Analysis/include/Luau/AnyTypeSummary.h

@@ -0,0 +1,148 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#pragma once
+
+#include "Luau/AstQuery.h"
+#include "Luau/Config.h"
+#include "Luau/ModuleResolver.h"
+#include "Luau/Scope.h"
+#include "Luau/Variant.h"
+#include "Luau/Normalize.h"
+#include "Luau/TypePack.h"
+#include "Luau/TypeArena.h"
+
+#include <mutex>
+#include <string>
+#include <vector>
+#include <optional>
+
+namespace Luau
+{
+
+class AstStat;
+class ParseError;
+struct TypeError;
+struct LintWarning;
+struct GlobalTypes;
+struct ModuleResolver;
+struct ParseResult;
+struct DcrLogger;
+
+struct TelemetryTypePair
+{
+    std::string annotatedType;
+    std::string inferredType;
+};
+
+struct AnyTypeSummary
+{
+    TypeArena arena;
+
+    AstStatBlock* rootSrc = nullptr;
+    DenseHashSet<TypeId> seenTypeFamilyInstances{nullptr};
+
+    int recursionCount = 0;
+
+    std::string root;
+    int strictCount = 0;
+
+    DenseHashMap<const void*, bool> seen{nullptr};
+
+    AnyTypeSummary();
+
+    void traverse(const Module* module, AstStat* src, NotNull<BuiltinTypes> builtinTypes);
+
+    std::pair<bool, TypeId> checkForAnyCast(const Scope* scope, AstExprTypeAssertion* expr);
+
+    bool containsAny(TypePackId typ);
+    bool containsAny(TypeId typ);
+
+    bool isAnyCast(const Scope* scope, AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    bool isAnyCall(const Scope* scope, AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+
+    bool hasVariadicAnys(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    bool hasArgAnys(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    bool hasAnyReturns(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+
+    TypeId checkForFamilyInhabitance(const TypeId instance, Location location);
+    TypeId lookupType(const AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    TypePackId reconstructTypePack(const AstArray<AstExpr*> exprs, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+
+    DenseHashSet<TypeId> seenTypeFunctionInstances{nullptr};
+    TypeId lookupAnnotation(AstType* annotation, const Module* module, NotNull<BuiltinTypes> builtintypes);
+    std::optional<TypePackId> lookupPackAnnotation(AstTypePack* annotation, const Module* module);
+    TypeId checkForTypeFunctionInhabitance(const TypeId instance, const Location location);
+
+    enum Pattern : uint64_t
+    {
+        Casts,
+        FuncArg,
+        FuncRet,
+        FuncApp,
+        VarAnnot,
+        VarAny,
+        TableProp,
+        Alias,
+        Assign,
+        TypePk
+    };
+
+    struct TypeInfo
+    {
+        Pattern code;
+        std::string node;
+        TelemetryTypePair type;
+
+        explicit TypeInfo(Pattern code, std::string node, TelemetryTypePair type);
+    };
+
+    struct FindReturnAncestry final : public AstVisitor
+    {
+        AstNode* currNode{nullptr};
+        AstNode* stat{nullptr};
+        Position rootEnd;
+        bool found = false;
+
+        explicit FindReturnAncestry(AstNode* stat, Position rootEnd);
+
+        bool visit(AstType* node) override;
+        bool visit(AstNode* node) override;
+        bool visit(AstStatFunction* node) override;
+        bool visit(AstStatLocalFunction* node) override;
+    };
+
+    std::vector<TypeInfo> typeInfo;
+
+    /**
+     * Fabricates a scope that is a child of another scope.
+     * @param node the lexical node that the scope belongs to.
+     * @param parent the parent scope of the new scope. Must not be null.
+     */
+    const Scope* childScope(const AstNode* node, const Scope* parent);
+
+    std::optional<AstExpr*> matchRequire(const AstExprCall& call);
+    AstNode* getNode(AstStatBlock* root, AstNode* node);
+    const Scope* findInnerMostScope(const Location location, const Module* module);
+    const AstNode* findAstAncestryAtLocation(const AstStatBlock* root, AstNode* node);
+
+    void visit(const Scope* scope, AstStat* stat, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatBlock* block, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatIf* ifStatement, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatWhile* while_, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatRepeat* repeat, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatReturn* ret, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatLocal* local, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatFor* for_, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatForIn* forIn, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatAssign* assign, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatCompoundAssign* assign, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatFunction* function, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatLocalFunction* function, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatTypeAlias* alias, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatDeclareGlobal* declareGlobal, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatDeclareClass* declareClass, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatDeclareFunction* declareFunction, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatError* error, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+};
+
+} // namespace Luau

Analysis/include/Luau/BuiltinDefinitions.h

@@ -70,7 +70,6 @@ Property makeProperty(TypeId ty, std::optional<std::string> documentationSymbol
 void assignPropDocumentationSymbols(TableType::Props& props, const std::string& baseName);
 
 std::string getBuiltinDefinitionSource();
-std::string getTypeFunctionDefinitionSource();
 
 void addGlobalBinding(GlobalTypes& globals, const std::string& name, TypeId ty, const std::string& packageName);
 void addGlobalBinding(GlobalTypes& globals, const std::string& name, Binding binding);

Analysis/include/Luau/Constraint.h

@@ -50,7 +50,6 @@ struct GeneralizationConstraint
     TypeId sourceType;
 
     std::vector<TypeId> interiorTypes;
-    bool hasDeprecatedAttribute = false;
 };
 
 // variables ~ iterate iterator

Analysis/include/Luau/ConstraintGenerator.h

@@ -117,23 +117,18 @@ struct ConstraintGenerator
 
     // Needed to register all available type functions for execution at later stages.
     NotNull<TypeFunctionRuntime> typeFunctionRuntime;
-    DenseHashMap<const AstStatTypeFunction*, ScopePtr> astTypeFunctionEnvironmentScopes{nullptr};
-
     // Needed to resolve modules to make 'require' import types properly.
     NotNull<ModuleResolver> moduleResolver;
     // Occasionally constraint generation needs to produce an ICE.
     const NotNull<InternalErrorReporter> ice;
 
     ScopePtr globalScope;
-    ScopePtr typeFunctionScope;
 
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope;
     std::vector<RequireCycle> requireCycles;
 
     DenseHashMap<TypeId, TypeIds> localTypes{nullptr};
 
-    DenseHashMap<AstExpr*, Inference> inferredExprCache{nullptr};
-
     DcrLogger* logger;
 
     ConstraintGenerator(
@@ -145,7 +140,6 @@ struct ConstraintGenerator
         NotNull<BuiltinTypes> builtinTypes,
         NotNull<InternalErrorReporter> ice,
         const ScopePtr& globalScope,
-        const ScopePtr& typeFunctionScope,
         std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
         DcrLogger* logger,
         NotNull<DataFlowGraph> dfg,

Analysis/include/Luau/ConstraintSolver.h

@@ -365,7 +365,7 @@ public:
      * @returns a non-free type that generalizes the argument, or `std::nullopt` if one
      * does not exist
      */
-    std::optional<TypeId> generalizeFreeType(NotNull<Scope> scope, TypeId type);
+    std::optional<TypeId> generalizeFreeType(NotNull<Scope> scope, TypeId type, bool avoidSealingTables = false);
 
     /**
      * Checks the existing set of constraints to see if there exist any that contain

Analysis/include/Luau/DataFlowGraph.h

@@ -38,6 +38,8 @@ struct DataFlowGraph
     DefId getDef(const AstExpr* expr) const;
     // Look up the definition optionally, knowing it may not be present.
     std::optional<DefId> getDefOptional(const AstExpr* expr) const;
+    // Look up for the rvalue def for a compound assignment.
+    std::optional<DefId> getRValueDefForCompoundAssign(const AstExpr* expr) const;
 
     DefId getDef(const AstLocal* local) const;
 
@@ -64,6 +66,10 @@ private:
     // All keys in this maps are really only statements that ambiently declares a symbol.
     DenseHashMap<const AstStat*, const Def*> declaredDefs{nullptr};
 
+    // Compound assignments are in a weird situation where the local being assigned to is also being used at its
+    // previous type implicitly in an rvalue position. This map provides the previous binding.
+    DenseHashMap<const AstExpr*, const Def*> compoundAssignDefs{nullptr};
+
     DenseHashMap<const AstExpr*, const RefinementKey*> astRefinementKeys{nullptr};
     friend struct DataFlowGraphBuilder;
 };

Analysis/include/Luau/FragmentAutocomplete.h

@@ -49,8 +49,6 @@ struct FragmentAutocompleteAncestryResult
     std::vector<AstLocal*> localStack;
     std::vector<AstNode*> ancestry;
     AstStat* nearestStatement = nullptr;
-    AstStatBlock* parentBlock = nullptr;
-    Location fragmentSelectionRegion;
 };
 
 struct FragmentParseResult
@@ -61,7 +59,6 @@ struct FragmentParseResult
     AstStat* nearestStatement = nullptr;
     std::vector<Comment> commentLocations;
     std::unique_ptr<Allocator> alloc = std::make_unique<Allocator>();
-    Position scopePos{0, 0};
 };
 
 struct FragmentTypeCheckResult
@@ -79,29 +76,10 @@ struct FragmentAutocompleteResult
     AutocompleteResult acResults;
 };
 
-struct FragmentRegion
-{
-    Location fragmentLocation;
-    AstStat* nearestStatement = nullptr; // used for tests
-    AstStatBlock* parentBlock = nullptr; // used for scope detection
-};
-
-std::optional<Position> blockDiffStart(AstStatBlock* blockOld, AstStatBlock* blockNew, AstStat* nearestStatementNewAst);
-FragmentRegion getFragmentRegion(AstStatBlock* root, const Position& cursorPosition);
-FragmentAutocompleteAncestryResult findAncestryForFragmentParse(AstStatBlock* stale, const Position& cursorPos, AstStatBlock* lastGoodParse);
-FragmentAutocompleteAncestryResult findAncestryForFragmentParse_DEPRECATED(AstStatBlock* root, const Position& cursorPos);
-
-std::optional<FragmentParseResult> parseFragment_DEPRECATED(
-    AstStatBlock* root,
-    AstNameTable* names,
-    std::string_view src,
-    const Position& cursorPos,
-    std::optional<Position> fragmentEndPosition
-);
+FragmentAutocompleteAncestryResult findAncestryForFragmentParse(AstStatBlock* root, const Position& cursorPos);
 
 std::optional<FragmentParseResult> parseFragment(
-    AstStatBlock* stale,
-    AstStatBlock* mostRecentParse,
+    AstStatBlock* root,
     AstNameTable* names,
     std::string_view src,
     const Position& cursorPos,
@@ -115,7 +93,6 @@ std::pair<FragmentTypeCheckStatus, FragmentTypeCheckResult> typecheckFragment(
     std::optional<FrontendOptions> opts,
     std::string_view src,
     std::optional<Position> fragmentEndPosition,
-    AstStatBlock* recentParse = nullptr,
     IFragmentAutocompleteReporter* reporter = nullptr
 );
 
@@ -127,7 +104,6 @@ FragmentAutocompleteResult fragmentAutocomplete(
     std::optional<FrontendOptions> opts,
     StringCompletionCallback callback,
     std::optional<Position> fragmentEndPosition = std::nullopt,
-    AstStatBlock* recentParse = nullptr,
     IFragmentAutocompleteReporter* reporter = nullptr
 );
 

Analysis/include/Luau/Frontend.h

@@ -10,6 +10,7 @@
 #include "Luau/Set.h"
 #include "Luau/TypeCheckLimits.h"
 #include "Luau/Variant.h"
+#include "Luau/AnyTypeSummary.h"
 
 #include <mutex>
 #include <string>
@@ -33,6 +34,7 @@ struct HotComment;
 struct BuildQueueItem;
 struct BuildQueueWorkState;
 struct FrontendCancellationToken;
+struct AnyTypeSummary;
 
 struct LoadDefinitionFileResult
 {
@@ -215,6 +217,11 @@ struct Frontend
         std::function<void(std::function<void()> task)> executeTask = {},
         std::function<bool(size_t done, size_t total)> progress = {}
     );
+    std::vector<ModuleName> checkQueuedModules_DEPRECATED(
+        std::optional<FrontendOptions> optionOverride = {},
+        std::function<void(std::function<void()> task)> executeTask = {},
+        std::function<bool(size_t done, size_t total)> progress = {}
+    );
 
     std::optional<CheckResult> getCheckResult(const ModuleName& name, bool accumulateNested, bool forAutocomplete = false);
     std::vector<ModuleName> getRequiredScripts(const ModuleName& name);
@@ -298,7 +305,6 @@ ModulePtr check(
     NotNull<ModuleResolver> moduleResolver,
     NotNull<FileResolver> fileResolver,
     const ScopePtr& globalScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     FrontendOptions options,
     TypeCheckLimits limits
@@ -313,7 +319,6 @@ ModulePtr check(
     NotNull<ModuleResolver> moduleResolver,
     NotNull<FileResolver> fileResolver,
     const ScopePtr& globalScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     FrontendOptions options,
     TypeCheckLimits limits,

Analysis/include/Luau/Generalization.h

@@ -12,8 +12,8 @@ std::optional<TypeId> generalize(
     NotNull<TypeArena> arena,
     NotNull<BuiltinTypes> builtinTypes,
     NotNull<Scope> scope,
-    NotNull<DenseHashSet<TypeId>> cachedTypes,
-    TypeId ty
+    NotNull<DenseHashSet<TypeId>> bakedTypes,
+    TypeId ty,
+    /* avoid sealing tables*/ bool avoidSealingTables = false
 );
-
 }

Analysis/include/Luau/GlobalTypes.h

@@ -19,9 +19,7 @@ struct GlobalTypes
 
     TypeArena globalTypes;
     SourceModule globalNames; // names for symbols entered into globalScope
-
     ScopePtr globalScope;     // shared by all modules
-    ScopePtr globalTypeFunctionScope; // shared by all modules
 };
 
 } // namespace Luau

Analysis/include/Luau/Module.h

@@ -8,6 +8,7 @@
 #include "Luau/ParseResult.h"
 #include "Luau/Scope.h"
 #include "Luau/TypeArena.h"
+#include "Luau/AnyTypeSummary.h"
 #include "Luau/DataFlowGraph.h"
 
 #include <memory>
@@ -15,16 +16,19 @@
 #include <unordered_map>
 #include <optional>
 
+LUAU_FASTFLAG(LuauIncrementalAutocompleteCommentDetection)
+
 namespace Luau
 {
 
-using LogLuauProc = void (*)(std::string_view, std::string_view);
+using LogLuauProc = void (*)(std::string_view);
 extern LogLuauProc logLuau;
 
 void setLogLuau(LogLuauProc ll);
 void resetLogLuauProc();
 
 struct Module;
+struct AnyTypeSummary;
 
 using ScopePtr = std::shared_ptr<struct Scope>;
 using ModulePtr = std::shared_ptr<Module>;
@@ -82,6 +86,10 @@ struct Module
     TypeArena interfaceTypes;
     TypeArena internalTypes;
 
+    // Summary of Ast Nodes that either contain
+    // user annotated anys or typechecker inferred anys
+    AnyTypeSummary ats{};
+
     // Scopes and AST types refer to parse data, so we need to keep that alive
     std::shared_ptr<Allocator> allocator;
     std::shared_ptr<AstNameTable> names;

Analysis/include/Luau/NonStrictTypeChecker.h

@@ -1,10 +1,9 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #pragma once
 
-#include "Luau/DataFlowGraph.h"
-#include "Luau/EqSatSimplification.h"
 #include "Luau/Module.h"
 #include "Luau/NotNull.h"
+#include "Luau/DataFlowGraph.h"
 
 namespace Luau
 {

Analysis/include/Luau/Scope.h

@@ -35,7 +35,7 @@ struct Scope
     explicit Scope(TypePackId returnType);                    // root scope
     explicit Scope(const ScopePtr& parent, int subLevel = 0); // child scope.  Parent must not be nullptr.
 
-    ScopePtr parent; // null for the root
+    const ScopePtr parent; // null for the root
 
     // All the children of this scope.
     std::vector<NotNull<Scope>> children;
@@ -59,8 +59,6 @@ struct Scope
 
     std::optional<TypeId> lookup(Symbol sym) const;
     std::optional<TypeId> lookupUnrefinedType(DefId def) const;
-
-    std::optional<TypeId> lookupRValueRefinementType(DefId def) const;
     std::optional<TypeId> lookup(DefId def) const;
     std::optional<std::pair<TypeId, Scope*>> lookupEx(DefId def);
     std::optional<std::pair<Binding*, Scope*>> lookupEx(Symbol sym);
@@ -73,7 +71,6 @@ struct Scope
 
     // WARNING: This function linearly scans for a string key of equal value!  It is thus O(n**2)
     std::optional<Binding> linearSearchForBinding(const std::string& name, bool traverseScopeChain = true) const;
-    std::optional<std::pair<Symbol, Binding>> linearSearchForBindingPair(const std::string& name, bool traverseScopeChain) const;
 
     RefinementMap refinements;
 

Analysis/include/Luau/TxnLog.h

@@ -192,6 +192,16 @@ struct TxnLog
     // The pointer returned lives until `commit` or `clear` is called.
     PendingTypePack* changeLevel(TypePackId tp, TypeLevel newLevel);
 
+    // Queues the replacement of a type's scope with the provided scope.
+    //
+    // The pointer returned lives until `commit` or `clear` is called.
+    PendingType* changeScope(TypeId ty, NotNull<Scope> scope);
+
+    // Queues the replacement of a type pack's scope with the provided scope.
+    //
+    // The pointer returned lives until `commit` or `clear` is called.
+    PendingTypePack* changeScope(TypePackId tp, NotNull<Scope> scope);
+
     // Queues a replacement of a table type with another table type with a new
     // indexer.
     //

Analysis/include/Luau/Type.h

@@ -19,6 +19,7 @@
 #include <optional>
 #include <set>
 #include <string>
+#include <unordered_map>
 #include <vector>
 
 LUAU_FASTINT(LuauTableTypeMaximumStringifierLength)
@@ -37,15 +38,6 @@ struct Constraint;
 struct Subtyping;
 struct TypeChecker2;
 
-enum struct Polarity : uint8_t
-{
-    None = 0b000,
-    Positive = 0b001,
-    Negative = 0b010,
-    Mixed = 0b011,
-    Unknown = 0b100,
-};
-
 /**
  * There are three kinds of type variables:
  * - `Free` variables are metavariables, which stand for unconstrained types.
@@ -356,8 +348,10 @@ struct FunctionType
     );
 
     // Local monomorphic function
+    FunctionType(TypeLevel level, TypePackId argTypes, TypePackId retTypes, std::optional<FunctionDefinition> defn = {}, bool hasSelf = false);
     FunctionType(
         TypeLevel level,
+        Scope* scope,
         TypePackId argTypes,
         TypePackId retTypes,
         std::optional<FunctionDefinition> defn = {},
@@ -374,6 +368,16 @@ struct FunctionType
         std::optional<FunctionDefinition> defn = {},
         bool hasSelf = false
     );
+    FunctionType(
+        TypeLevel level,
+        Scope* scope,
+        std::vector<TypeId> generics,
+        std::vector<TypePackId> genericPacks,
+        TypePackId argTypes,
+        TypePackId retTypes,
+        std::optional<FunctionDefinition> defn = {},
+        bool hasSelf = false
+    );
 
     std::optional<FunctionDefinition> definition;
     /// These should all be generic
@@ -382,6 +386,7 @@ struct FunctionType
     std::vector<std::optional<FunctionArgument>> argNames;
     Tags tags;
     TypeLevel level;
+    Scope* scope = nullptr;
     TypePackId argTypes;
     TypePackId retTypes;
     std::shared_ptr<MagicFunction> magic = nullptr;
@@ -391,7 +396,6 @@ struct FunctionType
     // this flag is used as an optimization to exit early from procedures that manipulate free or generic types.
     bool hasNoFreeOrGenericTypes = false;
     bool isCheckedFunction = false;
-    bool isDeprecatedFunction = false;
 };
 
 enum class TableState
@@ -468,9 +472,7 @@ struct Property
     TypeId type() const;
     void setType(TypeId ty);
 
-    // If this property has a present `writeTy`, set it equal to the `readTy`.
-    // This is to ensure that if we normalize a property that has divergent
-    // read and write types, we make them converge (for now).
+    // Sets the write type of this property to the read type.
     void makeShared();
 
     bool isShared() const;
@@ -515,6 +517,9 @@ struct TableType
     std::optional<TypeId> boundTo;
     Tags tags;
 
+    // Methods of this table that have an untyped self will use the same shared self type.
+    std::optional<TypeId> selfTy;
+
     // We track the number of as-yet-unadded properties to unsealed tables.
     // Some constraints will use this information to decide whether or not they
     // are able to dispatch.
@@ -617,6 +622,7 @@ struct UserDefinedFunctionData
     AstStatTypeFunction* definition = nullptr;
 
     DenseHashMap<Name, std::pair<AstStatTypeFunction*, size_t>> environment{""};
+    DenseHashMap<Name, AstStatTypeFunction*> environment_DEPRECATED{""};
 };
 
 /**
@@ -876,9 +882,6 @@ struct TypeFun
      */
     TypeId type;
 
-    // The location of where this TypeFun was defined, if available
-    std::optional<Location> definitionLocation;
-
     TypeFun() = default;
 
     explicit TypeFun(TypeId ty)
@@ -886,23 +889,16 @@ struct TypeFun
     {
     }
 
-    TypeFun(std::vector<GenericTypeDefinition> typeParams, TypeId type, std::optional<Location> definitionLocation = std::nullopt)
+    TypeFun(std::vector<GenericTypeDefinition> typeParams, TypeId type)
         : typeParams(std::move(typeParams))
         , type(type)
-        , definitionLocation(definitionLocation)
     {
     }
 
-    TypeFun(
-        std::vector<GenericTypeDefinition> typeParams,
-        std::vector<GenericTypePackDefinition> typePackParams,
-        TypeId type,
-        std::optional<Location> definitionLocation = std::nullopt
-    )
+    TypeFun(std::vector<GenericTypeDefinition> typeParams, std::vector<GenericTypePackDefinition> typePackParams, TypeId type)
         : typeParams(std::move(typeParams))
         , typePackParams(std::move(typePackParams))
         , type(type)
-        , definitionLocation(definitionLocation)
     {
     }
 

Analysis/include/Luau/TypeChecker2.h

@@ -13,8 +13,6 @@
 #include "Luau/TypeOrPack.h"
 #include "Luau/TypeUtils.h"
 
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
-
 namespace Luau
 {
 
@@ -40,29 +38,18 @@ struct Reasonings
 
     std::string toString()
     {
-        if (FFlag::LuauImproveTypePathsInErrors && reasons.empty())
-            return "";
-
         // DenseHashSet ordering is entirely undefined, so we want to
         // sort the reasons here to achieve a stable error
         // stringification.
         std::sort(reasons.begin(), reasons.end());
-        std::string allReasons = FFlag::LuauImproveTypePathsInErrors ? "\nthis is because " : "";
+        std::string allReasons;
         bool first = true;
         for (const std::string& reason : reasons)
         {
-            if (FFlag::LuauImproveTypePathsInErrors)
-            {
-                if (reasons.size() > 1)
-                    allReasons += "\n\t * ";
-            }
+            if (first)
+                first = false;
             else
-            {
-                if (first)
-                    first = false;
-                else
-                    allReasons += "\n\t";
-            }
+                allReasons += "\n\t";
 
             allReasons += reason;
         }

Analysis/include/Luau/TypeFunction.h

@@ -48,9 +48,6 @@ struct TypeFunctionRuntime
     // Evaluation of type functions should only be performed in the absence of parse errors in the source module
     bool allowEvaluation = true;
 
-    // Root scope in which the type function operates in, set up by ConstraintGenerator
-    ScopePtr rootScope;
-
     // Output created by 'print' function
     std::vector<std::string> messages;
 
@@ -177,7 +174,6 @@ struct FunctionGraphReductionResult
     DenseHashSet<TypePackId> blockedPacks{nullptr};
     DenseHashSet<TypeId> reducedTypes{nullptr};
     DenseHashSet<TypePackId> reducedPacks{nullptr};
-    DenseHashSet<TypeId> irreducibleTypes{nullptr};
 };
 
 /**

Analysis/include/Luau/TypeFunctionRuntime.h

@@ -223,6 +223,8 @@ struct TypeFunctionClassType
     std::optional<TypeFunctionTypeId> writeParent;
 
     TypeId classTy;
+
+    std::string name_DEPRECATED;
 };
 
 struct TypeFunctionGenericType

Analysis/include/Luau/TypeFunctionRuntimeBuilder.h

@@ -28,8 +28,14 @@ struct TypeFunctionRuntimeBuilderState
 {
     NotNull<TypeFunctionContext> ctx;
 
+    // Mapping of class name to ClassType
+    // Invariant: users can not create a new class types -> any class types that get deserialized must have been an argument to the type function
+    // Using this invariant, whenever a ClassType is serialized, we can put it into this map
+    // whenever a ClassType is deserialized, we can use this map to return the corresponding value
+    DenseHashMap<std::string, TypeId> classesSerialized_DEPRECATED{{}};
+
     // List of errors that occur during serialization/deserialization
-    // At every iteration of serialization/deserialization, if this list.size() != 0, we halt the process
+    // At every iteration of serialization/deserialzation, if this list.size() != 0, we halt the process
     std::vector<std::string> errors{};
 
     TypeFunctionRuntimeBuilderState(NotNull<TypeFunctionContext> ctx)

Analysis/include/Luau/TypePath.h

@@ -42,19 +42,9 @@ struct Property
 /// element.
 struct Index
 {
-    enum class Variant
-    {
-        Pack,
-        Union,
-        Intersection
-    };
-
     /// The 0-based index to use for the lookup.
     size_t index;
 
-    /// The sort of thing we're indexing from, this is used in stringifying the type path for errors.
-    Variant variant;
-
     bool operator==(const Index& other) const;
 };
 
@@ -215,9 +205,6 @@ using Path = TypePath::Path;
 /// terribly clear to end users of the Luau type system.
 std::string toString(const TypePath::Path& path, bool prefixDot = false);
 
-/// Converts a Path to a human readable string for error reporting.
-std::string toStringHuman(const TypePath::Path& path);
-
 std::optional<TypeOrPack> traverse(TypeId root, const Path& path, NotNull<BuiltinTypes> builtinTypes);
 std::optional<TypeOrPack> traverse(TypePackId root, const Path& path, NotNull<BuiltinTypes> builtinTypes);
 

Analysis/src/AnyTypeSummary.cpp

@@ -0,0 +1,902 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#include "Luau/AnyTypeSummary.h"
+
+#include "Luau/BuiltinDefinitions.h"
+#include "Luau/Clone.h"
+#include "Luau/Common.h"
+#include "Luau/Config.h"
+#include "Luau/ConstraintGenerator.h"
+#include "Luau/ConstraintSolver.h"
+#include "Luau/DataFlowGraph.h"
+#include "Luau/DcrLogger.h"
+#include "Luau/Module.h"
+#include "Luau/Parser.h"
+#include "Luau/Scope.h"
+#include "Luau/StringUtils.h"
+#include "Luau/TimeTrace.h"
+#include "Luau/ToString.h"
+#include "Luau/Transpiler.h"
+#include "Luau/TypeArena.h"
+#include "Luau/TypeChecker2.h"
+#include "Luau/NonStrictTypeChecker.h"
+#include "Luau/TypeInfer.h"
+#include "Luau/Variant.h"
+#include "Luau/VisitType.h"
+#include "Luau/TypePack.h"
+#include "Luau/TypeOrPack.h"
+
+#include <algorithm>
+#include <memory>
+#include <chrono>
+#include <condition_variable>
+#include <exception>
+#include <mutex>
+#include <stdexcept>
+#include <string>
+#include <iostream>
+
+
+#include <stdio.h>
+
+LUAU_FASTFLAGVARIABLE(StudioReportLuauAny2);
+LUAU_FASTINTVARIABLE(LuauAnySummaryRecursionLimit, 300);
+
+LUAU_FASTFLAG(DebugLuauMagicTypes);
+
+namespace Luau
+{
+
+void AnyTypeSummary::traverse(const Module* module, AstStat* src, NotNull<BuiltinTypes> builtinTypes)
+{
+    visit(findInnerMostScope(src->location, module), src, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStat* stat, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    RecursionLimiter limiter{&recursionCount, FInt::LuauAnySummaryRecursionLimit};
+
+    if (auto s = stat->as<AstStatBlock>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto i = stat->as<AstStatIf>())
+        return visit(scope, i, module, builtinTypes);
+    else if (auto s = stat->as<AstStatWhile>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatRepeat>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto r = stat->as<AstStatReturn>())
+        return visit(scope, r, module, builtinTypes);
+    else if (auto e = stat->as<AstStatExpr>())
+        return visit(scope, e, module, builtinTypes);
+    else if (auto s = stat->as<AstStatLocal>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatFor>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatForIn>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto a = stat->as<AstStatAssign>())
+        return visit(scope, a, module, builtinTypes);
+    else if (auto a = stat->as<AstStatCompoundAssign>())
+        return visit(scope, a, module, builtinTypes);
+    else if (auto f = stat->as<AstStatFunction>())
+        return visit(scope, f, module, builtinTypes);
+    else if (auto f = stat->as<AstStatLocalFunction>())
+        return visit(scope, f, module, builtinTypes);
+    else if (auto a = stat->as<AstStatTypeAlias>())
+        return visit(scope, a, module, builtinTypes);
+    else if (auto s = stat->as<AstStatDeclareGlobal>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatDeclareFunction>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatDeclareClass>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatError>())
+        return visit(scope, s, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatBlock* block, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    RecursionCounter counter{&recursionCount};
+
+    if (recursionCount >= FInt::LuauAnySummaryRecursionLimit)
+        return; // don't report
+
+    for (AstStat* stat : block->body)
+        visit(scope, stat, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatIf* ifStatement, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (ifStatement->thenbody)
+    {
+        const Scope* thenScope = findInnerMostScope(ifStatement->thenbody->location, module);
+        visit(thenScope, ifStatement->thenbody, module, builtinTypes);
+    }
+
+    if (ifStatement->elsebody)
+    {
+        const Scope* elseScope = findInnerMostScope(ifStatement->elsebody->location, module);
+        visit(elseScope, ifStatement->elsebody, module, builtinTypes);
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatWhile* while_, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* whileScope = findInnerMostScope(while_->location, module);
+    visit(whileScope, while_->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatRepeat* repeat, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* repeatScope = findInnerMostScope(repeat->location, module);
+    visit(repeatScope, repeat->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatReturn* ret, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* retScope = findInnerMostScope(ret->location, module);
+
+    auto ctxNode = getNode(rootSrc, ret);
+    bool seenTP = false;
+
+    for (auto val : ret->list)
+    {
+        if (isAnyCall(retScope, val, module, builtinTypes))
+        {
+            TelemetryTypePair types;
+            types.inferredType = toString(lookupType(val, module, builtinTypes));
+            TypeInfo ti{Pattern::FuncApp, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+
+        if (isAnyCast(retScope, val, module, builtinTypes))
+        {
+            if (auto cast = val->as<AstExprTypeAssertion>())
+            {
+                TelemetryTypePair types;
+
+                types.annotatedType = toString(lookupAnnotation(cast->annotation, module, builtinTypes));
+                types.inferredType = toString(lookupType(cast->expr, module, builtinTypes));
+
+                TypeInfo ti{Pattern::Casts, toString(ctxNode), types};
+                typeInfo.push_back(ti);
+            }
+        }
+
+        if (ret->list.size > 1 && !seenTP)
+        {
+            if (containsAny(retScope->returnType))
+            {
+                seenTP = true;
+
+                TelemetryTypePair types;
+
+                types.inferredType = toString(retScope->returnType);
+
+                TypeInfo ti{Pattern::TypePk, toString(ctxNode), types};
+                typeInfo.push_back(ti);
+            }
+        }
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatLocal* local, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, local);
+
+    TypePackId values = reconstructTypePack(local->values, module, builtinTypes);
+    auto [head, tail] = flatten(values);
+
+    size_t posn = 0;
+    for (AstLocal* loc : local->vars)
+    {
+        if (local->vars.data[0] == loc && posn < local->values.size)
+        {
+            if (loc->annotation)
+            {
+                auto annot = lookupAnnotation(loc->annotation, module, builtinTypes);
+                if (containsAny(annot))
+                {
+                    TelemetryTypePair types;
+
+                    types.annotatedType = toString(annot);
+                    types.inferredType = toString(lookupType(local->values.data[posn], module, builtinTypes));
+
+                    TypeInfo ti{Pattern::VarAnnot, toString(ctxNode), types};
+                    typeInfo.push_back(ti);
+                }
+            }
+
+            const AstExprTypeAssertion* maybeRequire = local->values.data[posn]->as<AstExprTypeAssertion>();
+            if (!maybeRequire)
+                continue;
+
+            if (std::min(local->values.size - 1, posn) < head.size())
+            {
+                if (isAnyCast(scope, local->values.data[posn], module, builtinTypes))
+                {
+                    TelemetryTypePair types;
+
+                    types.inferredType = toString(head[std::min(local->values.size - 1, posn)]);
+
+                    TypeInfo ti{Pattern::Casts, toString(ctxNode), types};
+                    typeInfo.push_back(ti);
+                }
+            }
+        }
+        else
+        {
+
+            if (std::min(local->values.size - 1, posn) < head.size())
+            {
+                if (loc->annotation)
+                {
+                    auto annot = lookupAnnotation(loc->annotation, module, builtinTypes);
+                    if (containsAny(annot))
+                    {
+                        TelemetryTypePair types;
+
+                        types.annotatedType = toString(annot);
+                        types.inferredType = toString(head[std::min(local->values.size - 1, posn)]);
+
+                        TypeInfo ti{Pattern::VarAnnot, toString(ctxNode), types};
+                        typeInfo.push_back(ti);
+                    }
+                }
+            }
+            else
+            {
+                if (tail)
+                {
+                    if (containsAny(*tail))
+                    {
+                        TelemetryTypePair types;
+
+                        types.inferredType = toString(*tail);
+
+                        TypeInfo ti{Pattern::VarAny, toString(ctxNode), types};
+                        typeInfo.push_back(ti);
+                    }
+                }
+            }
+        }
+
+        ++posn;
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatFor* for_, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* forScope = findInnerMostScope(for_->location, module);
+    visit(forScope, for_->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatForIn* forIn, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* loopScope = findInnerMostScope(forIn->location, module);
+    visit(loopScope, forIn->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatAssign* assign, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, assign);
+
+    TypePackId values = reconstructTypePack(assign->values, module, builtinTypes);
+    auto [head, tail] = flatten(values);
+
+    size_t posn = 0;
+    for (AstExpr* var : assign->vars)
+    {
+        TypeId tp = lookupType(var, module, builtinTypes);
+        if (containsAny(tp))
+        {
+            TelemetryTypePair types;
+
+            types.annotatedType = toString(tp);
+
+            auto loc = std::min(assign->vars.size - 1, posn);
+            if (head.size() >= assign->vars.size && posn < head.size())
+            {
+                types.inferredType = toString(head[posn]);
+            }
+            else if (loc < head.size())
+                types.inferredType = toString(head[loc]);
+            else
+                types.inferredType = toString(builtinTypes->nilType);
+
+            TypeInfo ti{Pattern::Assign, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+        ++posn;
+    }
+
+    for (AstExpr* val : assign->values)
+    {
+        if (isAnyCall(scope, val, module, builtinTypes))
+        {
+            TelemetryTypePair types;
+
+            types.inferredType = toString(lookupType(val, module, builtinTypes));
+
+            TypeInfo ti{Pattern::FuncApp, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+
+        if (isAnyCast(scope, val, module, builtinTypes))
+        {
+            if (auto cast = val->as<AstExprTypeAssertion>())
+            {
+                TelemetryTypePair types;
+
+                types.annotatedType = toString(lookupAnnotation(cast->annotation, module, builtinTypes));
+                types.inferredType = toString(lookupType(val, module, builtinTypes));
+
+                TypeInfo ti{Pattern::Casts, toString(ctxNode), types};
+                typeInfo.push_back(ti);
+            }
+        }
+    }
+
+    if (tail)
+    {
+        if (containsAny(*tail))
+        {
+            TelemetryTypePair types;
+
+            types.inferredType = toString(*tail);
+
+            TypeInfo ti{Pattern::Assign, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatCompoundAssign* assign, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, assign);
+
+    TelemetryTypePair types;
+
+    types.inferredType = toString(lookupType(assign->value, module, builtinTypes));
+    types.annotatedType = toString(lookupType(assign->var, module, builtinTypes));
+
+    if (module->astTypes.contains(assign->var))
+    {
+        if (containsAny(*module->astTypes.find(assign->var)))
+        {
+            TypeInfo ti{Pattern::Assign, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+    }
+    else if (module->astTypePacks.contains(assign->var))
+    {
+        if (containsAny(*module->astTypePacks.find(assign->var)))
+        {
+            TypeInfo ti{Pattern::Assign, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+    }
+
+    if (isAnyCall(scope, assign->value, module, builtinTypes))
+    {
+        TypeInfo ti{Pattern::FuncApp, toString(ctxNode), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (isAnyCast(scope, assign->value, module, builtinTypes))
+    {
+        if (auto cast = assign->value->as<AstExprTypeAssertion>())
+        {
+            types.annotatedType = toString(lookupAnnotation(cast->annotation, module, builtinTypes));
+            types.inferredType = toString(lookupType(cast->expr, module, builtinTypes));
+
+            TypeInfo ti{Pattern::Casts, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatFunction* function, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    TelemetryTypePair types;
+    types.inferredType = toString(lookupType(function->func, module, builtinTypes));
+
+    if (hasVariadicAnys(scope, function->func, module, builtinTypes))
+    {
+        TypeInfo ti{Pattern::VarAny, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (hasArgAnys(scope, function->func, module, builtinTypes))
+    {
+        TypeInfo ti{Pattern::FuncArg, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (hasAnyReturns(scope, function->func, module, builtinTypes))
+    {
+        TypeInfo ti{Pattern::FuncRet, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (function->func->body->body.size > 0)
+        visit(scope, function->func->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatLocalFunction* function, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    TelemetryTypePair types;
+
+    if (hasVariadicAnys(scope, function->func, module, builtinTypes))
+    {
+        types.inferredType = toString(lookupType(function->func, module, builtinTypes));
+        TypeInfo ti{Pattern::VarAny, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (hasArgAnys(scope, function->func, module, builtinTypes))
+    {
+        types.inferredType = toString(lookupType(function->func, module, builtinTypes));
+        TypeInfo ti{Pattern::FuncArg, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (hasAnyReturns(scope, function->func, module, builtinTypes))
+    {
+        types.inferredType = toString(lookupType(function->func, module, builtinTypes));
+        TypeInfo ti{Pattern::FuncRet, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (function->func->body->body.size > 0)
+        visit(scope, function->func->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatTypeAlias* alias, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, alias);
+
+    auto annot = lookupAnnotation(alias->type, module, builtinTypes);
+    if (containsAny(annot))
+    {
+        // no expr => no inference for aliases
+        TelemetryTypePair types;
+
+        types.annotatedType = toString(annot);
+        TypeInfo ti{Pattern::Alias, toString(ctxNode), types};
+        typeInfo.push_back(ti);
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, expr);
+
+    if (isAnyCall(scope, expr->expr, module, builtinTypes))
+    {
+        TelemetryTypePair types;
+        types.inferredType = toString(lookupType(expr->expr, module, builtinTypes));
+
+        TypeInfo ti{Pattern::FuncApp, toString(ctxNode), types};
+        typeInfo.push_back(ti);
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatDeclareGlobal* declareGlobal, const Module* module, NotNull<BuiltinTypes> builtinTypes) {}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatDeclareClass* declareClass, const Module* module, NotNull<BuiltinTypes> builtinTypes) {}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatDeclareFunction* declareFunction, const Module* module, NotNull<BuiltinTypes> builtinTypes) {}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatError* error, const Module* module, NotNull<BuiltinTypes> builtinTypes) {}
+
+TypeId AnyTypeSummary::checkForFamilyInhabitance(const TypeId instance, const Location location)
+{
+    if (seenTypeFamilyInstances.find(instance))
+        return instance;
+
+    seenTypeFamilyInstances.insert(instance);
+    return instance;
+}
+
+TypeId AnyTypeSummary::lookupType(const AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const TypeId* ty = module->astTypes.find(expr);
+    if (ty)
+        return checkForFamilyInhabitance(follow(*ty), expr->location);
+
+    const TypePackId* tp = module->astTypePacks.find(expr);
+    if (tp)
+    {
+        if (auto fst = first(*tp, /*ignoreHiddenVariadics*/ false))
+            return checkForFamilyInhabitance(*fst, expr->location);
+        else if (finite(*tp) && size(*tp) == 0)
+            return checkForFamilyInhabitance(builtinTypes->nilType, expr->location);
+    }
+
+    return builtinTypes->errorRecoveryType();
+}
+
+TypePackId AnyTypeSummary::reconstructTypePack(AstArray<AstExpr*> exprs, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (exprs.size == 0)
+        return arena.addTypePack(TypePack{{}, std::nullopt});
+
+    std::vector<TypeId> head;
+
+    for (size_t i = 0; i < exprs.size - 1; ++i)
+    {
+        head.push_back(lookupType(exprs.data[i], module, builtinTypes));
+    }
+
+    const TypePackId* tail = module->astTypePacks.find(exprs.data[exprs.size - 1]);
+    if (tail)
+        return arena.addTypePack(TypePack{std::move(head), follow(*tail)});
+    else
+        return arena.addTypePack(TypePack{std::move(head), builtinTypes->errorRecoveryTypePack()});
+}
+
+bool AnyTypeSummary::isAnyCall(const Scope* scope, AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (auto call = expr->as<AstExprCall>())
+    {
+        TypePackId args = reconstructTypePack(call->args, module, builtinTypes);
+        if (containsAny(args))
+            return true;
+
+        TypeId func = lookupType(call->func, module, builtinTypes);
+        if (containsAny(func))
+            return true;
+    }
+    return false;
+}
+
+bool AnyTypeSummary::hasVariadicAnys(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (expr->vararg && expr->varargAnnotation)
+    {
+        auto annot = lookupPackAnnotation(expr->varargAnnotation, module);
+        if (annot && containsAny(*annot))
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
+bool AnyTypeSummary::hasArgAnys(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (expr->args.size > 0)
+    {
+        for (const AstLocal* arg : expr->args)
+        {
+            if (arg->annotation)
+            {
+                auto annot = lookupAnnotation(arg->annotation, module, builtinTypes);
+                if (containsAny(annot))
+                {
+                    return true;
+                }
+            }
+        }
+    }
+    return false;
+}
+
+bool AnyTypeSummary::hasAnyReturns(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (!expr->returnAnnotation)
+    {
+        return false;
+    }
+
+    for (AstType* ret : expr->returnAnnotation->types)
+    {
+        if (containsAny(lookupAnnotation(ret, module, builtinTypes)))
+        {
+            return true;
+        }
+    }
+
+    if (expr->returnAnnotation->tailType)
+    {
+        auto annot = lookupPackAnnotation(expr->returnAnnotation->tailType, module);
+        if (annot && containsAny(*annot))
+        {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool AnyTypeSummary::isAnyCast(const Scope* scope, AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (auto cast = expr->as<AstExprTypeAssertion>())
+    {
+        auto annot = lookupAnnotation(cast->annotation, module, builtinTypes);
+        if (containsAny(annot))
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
+TypeId AnyTypeSummary::lookupAnnotation(AstType* annotation, const Module* module, NotNull<BuiltinTypes> builtintypes)
+{
+    if (FFlag::DebugLuauMagicTypes)
+    {
+        if (auto ref = annotation->as<AstTypeReference>(); ref && ref->parameters.size > 0)
+        {
+            if (auto ann = ref->parameters.data[0].type)
+            {
+                TypeId argTy = lookupAnnotation(ref->parameters.data[0].type, module, builtintypes);
+                return follow(argTy);
+            }
+        }
+    }
+
+    const TypeId* ty = module->astResolvedTypes.find(annotation);
+    if (ty)
+        return checkForTypeFunctionInhabitance(follow(*ty), annotation->location);
+    else
+        return checkForTypeFunctionInhabitance(builtintypes->errorRecoveryType(), annotation->location);
+}
+
+TypeId AnyTypeSummary::checkForTypeFunctionInhabitance(const TypeId instance, const Location location)
+{
+    if (seenTypeFunctionInstances.find(instance))
+        return instance;
+    seenTypeFunctionInstances.insert(instance);
+
+    return instance;
+}
+
+std::optional<TypePackId> AnyTypeSummary::lookupPackAnnotation(AstTypePack* annotation, const Module* module)
+{
+    const TypePackId* tp = module->astResolvedTypePacks.find(annotation);
+    if (tp != nullptr)
+        return {follow(*tp)};
+    return {};
+}
+
+bool AnyTypeSummary::containsAny(TypeId typ)
+{
+    typ = follow(typ);
+
+    if (auto t = seen.find(typ); t && !*t)
+    {
+        return false;
+    }
+
+    seen[typ] = false;
+
+    RecursionCounter counter{&recursionCount};
+    if (recursionCount >= FInt::LuauAnySummaryRecursionLimit)
+    {
+        return false;
+    }
+
+    bool found = false;
+
+    if (auto ty = get<AnyType>(typ))
+    {
+        found = true;
+    }
+    else if (auto ty = get<UnknownType>(typ))
+    {
+        found = true;
+    }
+    else if (auto ty = get<TableType>(typ))
+    {
+        for (auto& [_name, prop] : ty->props)
+        {
+            if (FFlag::LuauSolverV2)
+            {
+                if (auto newT = follow(prop.readTy))
+                {
+                    if (containsAny(*newT))
+                        found = true;
+                }
+                else if (auto newT = follow(prop.writeTy))
+                {
+                    if (containsAny(*newT))
+                        found = true;
+                }
+            }
+            else
+            {
+                if (containsAny(prop.type()))
+                    found = true;
+            }
+        }
+    }
+    else if (auto ty = get<IntersectionType>(typ))
+    {
+        for (auto part : ty->parts)
+        {
+            if (containsAny(part))
+            {
+                found = true;
+            }
+        }
+    }
+    else if (auto ty = get<UnionType>(typ))
+    {
+        for (auto option : ty->options)
+        {
+            if (containsAny(option))
+            {
+                found = true;
+            }
+        }
+    }
+    else if (auto ty = get<FunctionType>(typ))
+    {
+        if (containsAny(ty->argTypes))
+            found = true;
+        else if (containsAny(ty->retTypes))
+            found = true;
+    }
+
+    seen[typ] = found;
+
+    return found;
+}
+
+bool AnyTypeSummary::containsAny(TypePackId typ)
+{
+    typ = follow(typ);
+
+    if (auto t = seen.find(typ); t && !*t)
+    {
+        return false;
+    }
+
+    seen[typ] = false;
+
+    auto [head, tail] = flatten(typ);
+    bool found = false;
+
+    for (auto tp : head)
+    {
+        if (containsAny(tp))
+            found = true;
+    }
+
+    if (tail)
+    {
+        if (auto vtp = get<VariadicTypePack>(tail))
+        {
+            if (auto ty = get<AnyType>(follow(vtp->ty)))
+            {
+                found = true;
+            }
+        }
+        else if (auto tftp = get<TypeFunctionInstanceTypePack>(tail))
+        {
+
+            for (TypePackId tp : tftp->packArguments)
+            {
+                if (containsAny(tp))
+                {
+                    found = true;
+                }
+            }
+
+            for (TypeId t : tftp->typeArguments)
+            {
+                if (containsAny(t))
+                {
+                    found = true;
+                }
+            }
+        }
+    }
+
+    seen[typ] = found;
+
+    return found;
+}
+
+const Scope* AnyTypeSummary::findInnerMostScope(const Location location, const Module* module)
+{
+    const Scope* bestScope = module->getModuleScope().get();
+
+    bool didNarrow = false;
+    do
+    {
+        didNarrow = false;
+        for (auto scope : bestScope->children)
+        {
+            if (scope->location.encloses(location))
+            {
+                bestScope = scope.get();
+                didNarrow = true;
+                break;
+            }
+        }
+    } while (didNarrow && bestScope->children.size() > 0);
+
+    return bestScope;
+}
+
+std::optional<AstExpr*> AnyTypeSummary::matchRequire(const AstExprCall& call)
+{
+    const char* require = "require";
+
+    if (call.args.size != 1)
+        return std::nullopt;
+
+    const AstExprGlobal* funcAsGlobal = call.func->as<AstExprGlobal>();
+    if (!funcAsGlobal || funcAsGlobal->name != require)
+        return std::nullopt;
+
+    if (call.args.size != 1)
+        return std::nullopt;
+
+    return call.args.data[0];
+}
+
+AstNode* AnyTypeSummary::getNode(AstStatBlock* root, AstNode* node)
+{
+    FindReturnAncestry finder(node, root->location.end);
+    root->visit(&finder);
+
+    if (!finder.currNode)
+        finder.currNode = node;
+
+    LUAU_ASSERT(finder.found && finder.currNode);
+    return finder.currNode;
+}
+
+bool AnyTypeSummary::FindReturnAncestry::visit(AstStatLocalFunction* node)
+{
+    currNode = node;
+    return !found;
+}
+
+bool AnyTypeSummary::FindReturnAncestry::visit(AstStatFunction* node)
+{
+    currNode = node;
+    return !found;
+}
+
+bool AnyTypeSummary::FindReturnAncestry::visit(AstType* node)
+{
+    return !found;
+}
+
+bool AnyTypeSummary::FindReturnAncestry::visit(AstNode* node)
+{
+    if (node == stat)
+    {
+        found = true;
+    }
+
+    if (node->location.end == rootEnd && stat->location.end >= rootEnd)
+    {
+        currNode = node;
+        found = true;
+    }
+
+    return !found;
+}
+
+
+AnyTypeSummary::TypeInfo::TypeInfo(Pattern code, std::string node, TelemetryTypePair type)
+    : code(code)
+    , node(node)
+    , type(type)
+{
+}
+
+AnyTypeSummary::FindReturnAncestry::FindReturnAncestry(AstNode* stat, Position rootEnd)
+    : stat(stat)
+    , rootEnd(rootEnd)
+{
+}
+
+AnyTypeSummary::AnyTypeSummary() {}
+
+} // namespace Luau

Analysis/src/AstJsonEncoder.cpp

@@ -1065,11 +1065,6 @@ struct AstJsonEncoder : public AstVisitor
         );
     }
 
-    void write(class AstTypeOptional* node)
-    {
-        writeNode(node, "AstTypeOptional", [&]() {});
-    }
-
     void write(class AstTypeUnion* node)
     {
         writeNode(
@@ -1151,8 +1146,6 @@ struct AstJsonEncoder : public AstVisitor
             return writeString("checked");
         case AstAttr::Type::Native:
             return writeString("native");
-        case AstAttr::Type::Deprecated:
-            return writeString("deprecated");
         }
     }
 

Analysis/src/AutocompleteCore.cpp

@@ -30,7 +30,6 @@ LUAU_FASTFLAG(LuauExposeRequireByStringAutocomplete)
 LUAU_FASTFLAGVARIABLE(LuauAutocompleteRefactorsForIncrementalAutocomplete)
 
 LUAU_FASTFLAGVARIABLE(LuauAutocompleteUsesModuleForTypeCompatibility)
-LUAU_FASTFLAGVARIABLE(LuauAutocompleteUnionCopyPreviousSeen)
 
 static const std::unordered_set<std::string> kStatementStartingKeywords =
     {"while", "if", "local", "repeat", "function", "do", "for", "return", "break", "continue", "type", "export"};
@@ -485,21 +484,6 @@ static void autocompleteProps(
             AutocompleteEntryMap inner;
             std::unordered_set<TypeId> innerSeen;
 
-            // If we don't do this, and we have the misfortune of receiving a
-            // recursive union like:
-            //
-            //  t1 where t1 = t1 | Class
-            //
-            // Then we are on a one way journey to a stack overflow.
-            if (FFlag::LuauAutocompleteUnionCopyPreviousSeen)
-            {
-                for (auto ty: seen)
-                {
-                    if (is<UnionType, IntersectionType>(ty))
-                        innerSeen.insert(ty);
-                }
-            }
-
             if (isNil(*iter))
             {
                 ++iter;

Analysis/src/BuiltinDefinitions.cpp

@@ -29,10 +29,11 @@
  */
 
 LUAU_FASTFLAG(LuauSolverV2)
+LUAU_FASTFLAGVARIABLE(LuauStringFormatErrorSuppression)
 LUAU_FASTFLAGVARIABLE(LuauTableCloneClonesType3)
 LUAU_FASTFLAG(LuauTrackInteriorFreeTypesOnScope)
+LUAU_FASTFLAGVARIABLE(LuauFreezeIgnorePersistent)
 LUAU_FASTFLAGVARIABLE(LuauFollowTableFreeze)
-LUAU_FASTFLAGVARIABLE(LuauUserTypeFunTypecheck)
 
 namespace Luau
 {
@@ -287,22 +288,6 @@ void assignPropDocumentationSymbols(TableType::Props& props, const std::string&
     }
 }
 
-static void finalizeGlobalBindings(ScopePtr scope)
-{
-    LUAU_ASSERT(FFlag::LuauUserTypeFunTypecheck);
-
-    for (const auto& pair : scope->bindings)
-    {
-        persist(pair.second.typeId);
-
-        if (TableType* ttv = getMutable<TableType>(pair.second.typeId))
-        {
-            if (!ttv->name)
-                ttv->name = "typeof(" + toString(pair.first) + ")";
-        }
-    }
-}
-
 void registerBuiltinGlobals(Frontend& frontend, GlobalTypes& globals, bool typeCheckForAutocomplete)
 {
     LUAU_ASSERT(!globals.globalTypes.types.isFrozen());
@@ -414,21 +399,14 @@ void registerBuiltinGlobals(Frontend& frontend, GlobalTypes& globals, bool typeC
         // clang-format on
     }
 
-    if (FFlag::LuauUserTypeFunTypecheck)
+    for (const auto& pair : globals.globalScope->bindings)
     {
-        finalizeGlobalBindings(globals.globalScope);
-    }
-    else
-    {
-        for (const auto& pair : globals.globalScope->bindings)
-        {
-            persist(pair.second.typeId);
+        persist(pair.second.typeId);
 
-            if (TableType* ttv = getMutable<TableType>(pair.second.typeId))
-            {
-                if (!ttv->name)
-                    ttv->name = "typeof(" + toString(pair.first) + ")";
-            }
+        if (TableType* ttv = getMutable<TableType>(pair.second.typeId))
+        {
+            if (!ttv->name)
+                ttv->name = "typeof(" + toString(pair.first) + ")";
         }
     }
 
@@ -489,59 +467,6 @@ void registerBuiltinGlobals(Frontend& frontend, GlobalTypes& globals, bool typeC
     TypeId requireTy = getGlobalBinding(globals, "require");
     attachTag(requireTy, kRequireTagName);
     attachMagicFunction(requireTy, std::make_shared<MagicRequire>());
-
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // Global scope cannot be the parent of the type checking environment because it can be changed by the embedder
-        globals.globalTypeFunctionScope->exportedTypeBindings = globals.globalScope->exportedTypeBindings;
-        globals.globalTypeFunctionScope->builtinTypeNames = globals.globalScope->builtinTypeNames;
-
-        // Type function runtime also removes a few standard libraries and globals, so we will take only the ones that are defined
-        static const char* typeFunctionRuntimeBindings[] = {
-            // Libraries
-            "math",
-            "table",
-            "string",
-            "bit32",
-            "utf8",
-            "buffer",
-
-            // Globals
-            "assert",
-            "error",
-            "print",
-            "next",
-            "ipairs",
-            "pairs",
-            "select",
-            "unpack",
-            "getmetatable",
-            "setmetatable",
-            "rawget",
-            "rawset",
-            "rawlen",
-            "rawequal",
-            "tonumber",
-            "tostring",
-            "type",
-            "typeof",
-        };
-
-        for (auto& name : typeFunctionRuntimeBindings)
-        {
-            AstName astName = globals.globalNames.names->get(name);
-            LUAU_ASSERT(astName.value);
-
-            globals.globalTypeFunctionScope->bindings[astName] = globals.globalScope->bindings[astName];
-        }
-
-        LoadDefinitionFileResult typeFunctionLoadResult = frontend.loadDefinitionFile(
-            globals, globals.globalTypeFunctionScope, getTypeFunctionDefinitionSource(), "@luau", /* captureComments */ false, false
-        );
-        LUAU_ASSERT(typeFunctionLoadResult.success);
-
-        finalizeGlobalBindings(globals.globalTypeFunctionScope);
-    }
 }
 
 static std::vector<TypeId> parseFormatString(NotNull<BuiltinTypes> builtinTypes, const char* data, size_t size)
@@ -711,8 +636,10 @@ bool MagicFormat::typeCheck(const MagicFunctionTypeCheckContext& context)
 
         if (!result.isSubtype)
         {
-            switch (shouldSuppressErrors(NotNull{&context.typechecker->normalizer}, actualTy))
+            if (FFlag::LuauStringFormatErrorSuppression)
             {
+                switch (shouldSuppressErrors(NotNull{&context.typechecker->normalizer}, actualTy))
+                {
                 case ErrorSuppression::Suppress:
                     break;
                 case ErrorSuppression::NormalizationFailed:
@@ -722,6 +649,12 @@ bool MagicFormat::typeCheck(const MagicFunctionTypeCheckContext& context)
 
                     if (!reasonings.suppressed)
                         context.typechecker->reportError(TypeMismatch{expectedTy, actualTy, reasonings.toString()}, location);
+                }
+            }
+            else
+            {
+                Reasonings reasonings = context.typechecker->explainReasonings(actualTy, expectedTy, location, result);
+                context.typechecker->reportError(TypeMismatch{expectedTy, actualTy, reasonings.toString()}, location);
             }
         }
     }
@@ -1511,7 +1444,7 @@ bool MagicClone::infer(const MagicFunctionCallContext& context)
         return false;
 
     CloneState cloneState{context.solver->builtinTypes};
-    TypeId resultType = shallowClone(inputType, *arena, cloneState, /* ignorePersistent */ true);
+    TypeId resultType = shallowClone(inputType, *arena, cloneState, /* ignorePersistent */ FFlag::LuauFreezeIgnorePersistent);
 
     if (auto tableType = getMutable<TableType>(resultType))
     {
@@ -1548,7 +1481,7 @@ static std::optional<TypeId> freezeTable(TypeId inputType, const MagicFunctionCa
     {
         // Clone the input type, this will become our final result type after we mutate it.
         CloneState cloneState{context.solver->builtinTypes};
-        TypeId resultType = shallowClone(inputType, *arena, cloneState, /* ignorePersistent */ true);
+        TypeId resultType = shallowClone(inputType, *arena, cloneState, /* ignorePersistent */ FFlag::LuauFreezeIgnorePersistent);
         auto tableTy = getMutable<TableType>(resultType);
         // `clone` should not break this.
         LUAU_ASSERT(tableTy);

Analysis/src/Clone.cpp

@@ -9,12 +9,13 @@
 #include "Luau/VisitType.h"
 
 LUAU_FASTFLAG(LuauSolverV2)
+LUAU_FASTFLAG(LuauFreezeIgnorePersistent)
 
 // For each `Luau::clone` call, we will clone only up to N amount of types _and_ packs, as controlled by this limit.
 LUAU_FASTINTVARIABLE(LuauTypeCloneIterationLimit, 100'000)
 LUAU_FASTFLAGVARIABLE(LuauClonedTableAndFunctionTypesMustHaveScopes)
 LUAU_FASTFLAGVARIABLE(LuauDoNotClonePersistentBindings)
-LUAU_FASTFLAG(LuauIncrementalAutocompleteDemandBasedCloning)
+
 namespace Luau
 {
 
@@ -133,7 +134,7 @@ protected:
         ty = follow(ty, FollowOption::DisableLazyTypeThunks);
         if (auto it = types->find(ty); it != types->end())
             return it->second;
-        else if (ty->persistent && ty != forceTy)
+        else if (ty->persistent && (!FFlag::LuauFreezeIgnorePersistent || ty != forceTy))
             return ty;
         return std::nullopt;
     }
@@ -143,7 +144,7 @@ protected:
         tp = follow(tp);
         if (auto it = packs->find(tp); it != packs->end())
             return it->second;
-        else if (tp->persistent && tp != forceTp)
+        else if (tp->persistent && (!FFlag::LuauFreezeIgnorePersistent || tp != forceTp))
             return tp;
         return std::nullopt;
     }
@@ -169,7 +170,7 @@ public:
 
         if (auto clone = find(ty))
             return *clone;
-        else if (ty->persistent && ty != forceTy)
+        else if (ty->persistent && (!FFlag::LuauFreezeIgnorePersistent || ty != forceTy))
             return ty;
 
         TypeId target = arena->addType(ty->ty);
@@ -179,6 +180,8 @@ public:
             generic->scope = nullptr;
         else if (auto free = getMutable<FreeType>(target))
             free->scope = nullptr;
+        else if (auto fn = getMutable<FunctionType>(target))
+            fn->scope = nullptr;
         else if (auto table = getMutable<TableType>(target))
             table->scope = nullptr;
 
@@ -193,7 +196,7 @@ public:
 
         if (auto clone = find(tp))
             return *clone;
-        else if (tp->persistent && tp != forceTp)
+        else if (tp->persistent && (!FFlag::LuauFreezeIgnorePersistent || tp != forceTp))
             return tp;
 
         TypePackId target = arena->addTypePack(tp->ty);
@@ -395,7 +398,7 @@ private:
             ty = shallowClone(ty);
     }
 
-    virtual void cloneChildren(LazyType* t)
+    void cloneChildren(LazyType* t)
     {
         if (auto unwrapped = t->unwrapped.load())
             t->unwrapped.store(shallowClone(unwrapped));
@@ -502,7 +505,7 @@ public:
 
         if (auto clone = find(ty))
             return *clone;
-        else if (ty->persistent && ty != forceTy)
+        else if (ty->persistent && (!FFlag::LuauFreezeIgnorePersistent || ty != forceTy))
             return ty;
 
         TypeId target = arena->addType(ty->ty);
@@ -519,6 +522,11 @@ public:
             if (FFlag::LuauClonedTableAndFunctionTypesMustHaveScopes)
                 tt->scope = replacementForNullScope;
         }
+        else if (auto fn = getMutable<FunctionType>(target))
+        {
+            if (FFlag::LuauClonedTableAndFunctionTypesMustHaveScopes)
+                fn->scope = replacementForNullScope;
+        }
 
         (*types)[ty] = target;
         queue.emplace_back(target);
@@ -531,7 +539,7 @@ public:
 
         if (auto clone = find(tp))
             return *clone;
-        else if (tp->persistent && tp != forceTp)
+        else if (tp->persistent && (!FFlag::LuauFreezeIgnorePersistent || tp != forceTp))
             return tp;
 
         TypePackId target = arena->addTypePack(tp->ty);
@@ -545,16 +553,6 @@ public:
         queue.emplace_back(target);
         return target;
     }
-
-    void cloneChildren(LazyType* t) override
-    {
-        // Do not clone lazy types
-        if (!FFlag::LuauIncrementalAutocompleteDemandBasedCloning)
-        {
-            if (auto unwrapped = t->unwrapped.load())
-                t->unwrapped.store(shallowClone(unwrapped));
-        }
-    }
 };
 
 
@@ -562,7 +560,7 @@ public:
 
 TypePackId shallowClone(TypePackId tp, TypeArena& dest, CloneState& cloneState, bool ignorePersistent)
 {
-    if (tp->persistent && !ignorePersistent)
+    if (tp->persistent && (!FFlag::LuauFreezeIgnorePersistent || !ignorePersistent))
         return tp;
 
     TypeCloner cloner{
@@ -571,7 +569,7 @@ TypePackId shallowClone(TypePackId tp, TypeArena& dest, CloneState& cloneState,
         NotNull{&cloneState.seenTypes},
         NotNull{&cloneState.seenTypePacks},
         nullptr,
-        ignorePersistent ? tp : nullptr
+        FFlag::LuauFreezeIgnorePersistent && ignorePersistent ? tp : nullptr
     };
 
     return cloner.shallowClone(tp);
@@ -579,7 +577,7 @@ TypePackId shallowClone(TypePackId tp, TypeArena& dest, CloneState& cloneState,
 
 TypeId shallowClone(TypeId typeId, TypeArena& dest, CloneState& cloneState, bool ignorePersistent)
 {
-    if (typeId->persistent && !ignorePersistent)
+    if (typeId->persistent && (!FFlag::LuauFreezeIgnorePersistent || !ignorePersistent))
         return typeId;
 
     TypeCloner cloner{
@@ -587,7 +585,7 @@ TypeId shallowClone(TypeId typeId, TypeArena& dest, CloneState& cloneState, bool
         cloneState.builtinTypes,
         NotNull{&cloneState.seenTypes},
         NotNull{&cloneState.seenTypePacks},
-        ignorePersistent ? typeId : nullptr,
+        FFlag::LuauFreezeIgnorePersistent && ignorePersistent ? typeId : nullptr,
         nullptr
     };
 

Analysis/src/ConstraintGenerator.cpp

@@ -33,10 +33,10 @@ LUAU_FASTINT(LuauCheckRecursionLimit)
 LUAU_FASTFLAG(DebugLuauLogSolverToJson)
 LUAU_FASTFLAG(DebugLuauMagicTypes)
 LUAU_FASTFLAG(LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
-LUAU_FASTFLAGVARIABLE(LuauPropagateExpectedTypesForCalls)
 LUAU_FASTFLAG(DebugLuauGreedyGeneralization)
 
 LUAU_FASTFLAGVARIABLE(LuauTrackInteriorFreeTypesOnScope)
+LUAU_FASTFLAGVARIABLE(LuauDeferBidirectionalInferenceForTableAssignment)
 LUAU_FASTFLAGVARIABLE(LuauUngeneralizedTypesForRecursiveFunctions)
 LUAU_FASTFLAGVARIABLE(LuauGlobalSelfAssignmentCycle)
 
@@ -44,12 +44,6 @@ LUAU_FASTFLAG(LuauFreeTypesMustHaveBounds)
 LUAU_FASTFLAGVARIABLE(LuauInferLocalTypesInMultipleAssignments)
 LUAU_FASTFLAGVARIABLE(LuauDoNotLeakNilInRefinement)
 LUAU_FASTFLAGVARIABLE(LuauExtraFollows)
-LUAU_FASTFLAG(LuauUserTypeFunTypecheck)
-LUAU_FASTFLAGVARIABLE(LuauRetainDefinitionAliasLocations)
-
-LUAU_FASTFLAG(LuauDeprecatedAttribute)
-LUAU_FASTFLAGVARIABLE(LuauCacheInferencePerAstExpr)
-LUAU_FASTFLAGVARIABLE(LuauAlwaysResolveAstTypes)
 
 namespace Luau
 {
@@ -190,7 +184,6 @@ ConstraintGenerator::ConstraintGenerator(
     NotNull<BuiltinTypes> builtinTypes,
     NotNull<InternalErrorReporter> ice,
     const ScopePtr& globalScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     DcrLogger* logger,
     NotNull<DataFlowGraph> dfg,
@@ -207,7 +200,6 @@ ConstraintGenerator::ConstraintGenerator(
     , moduleResolver(moduleResolver)
     , ice(ice)
     , globalScope(globalScope)
-    , typeFunctionScope(typeFunctionScope)
     , prepareModuleScope(std::move(prepareModuleScope))
     , requireCycles(std::move(requireCycles))
     , logger(logger)
@@ -229,15 +221,7 @@ void ConstraintGenerator::visitModuleRoot(AstStatBlock* block)
 
     rootScope->returnType = freshTypePack(scope);
 
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // Create module-local scope for the type function environment
-        ScopePtr localTypeFunctionScope = std::make_shared<Scope>(typeFunctionScope);
-        localTypeFunctionScope->location = block->location;
-        typeFunctionRuntime->rootScope = localTypeFunctionScope;
-    }
-
-    TypeId moduleFnTy = arena->addType(FunctionType{TypeLevel{}, builtinTypes->anyTypePack, rootScope->returnType});
+    TypeId moduleFnTy = arena->addType(FunctionType{TypeLevel{}, rootScope, builtinTypes->anyTypePack, rootScope->returnType});
     interiorTypes.emplace_back();
 
     prepopulateGlobalScope(scope, block);
@@ -715,9 +699,6 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
     std::unordered_map<Name, Location> aliasDefinitionLocations;
     std::unordered_map<Name, Location> classDefinitionLocations;
 
-    bool hasTypeFunction = false;
-    ScopePtr typeFunctionEnvScope;
-
     // In order to enable mutually-recursive type aliases, we need to
     // populate the type bindings before we actually check any of the
     // alias statements.
@@ -753,9 +734,6 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
                 initialFun.typePackParams.push_back(genPack);
             }
 
-            if (FFlag::LuauRetainDefinitionAliasLocations)
-                initialFun.definitionLocation = alias->location;
-
             if (alias->exported)
                 scope->exportedTypeBindings[alias->name.value] = std::move(initialFun);
             else
@@ -766,9 +744,6 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
         }
         else if (auto function = stat->as<AstStatTypeFunction>())
         {
-            if (FFlag::LuauUserTypeFunTypecheck)
-                hasTypeFunction = true;
-
             // If a type function w/ same name has already been defined, error for having duplicates
             if (scope->exportedTypeBindings.count(function->name.value) || scope->privateTypeBindings.count(function->name.value))
             {
@@ -778,8 +753,7 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
                 continue;
             }
 
-            // Variable becomes unused with the removal of FFlag::LuauUserTypeFunTypecheck
-            ScopePtr defnScope = FFlag::LuauUserTypeFunTypecheck ? nullptr : childScope(function, scope);
+            ScopePtr defnScope = childScope(function, scope);
 
             // Create TypeFunctionInstanceType
 
@@ -813,9 +787,6 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
 
             TypeFun typeFunction{std::move(quantifiedTypeParams), typeFunctionTy};
 
-            if (FFlag::LuauRetainDefinitionAliasLocations)
-                typeFunction.definitionLocation = function->location;
-
             // Set type bindings and definition locations for this user-defined type function
             if (function->exported)
                 scope->exportedTypeBindings[function->name.value] = std::move(typeFunction);
@@ -843,30 +814,17 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
 
             TypeId initialType = arena->addType(BlockedType{});
             TypeFun initialFun{initialType};
-            if (FFlag::LuauRetainDefinitionAliasLocations)
-                initialFun.definitionLocation = classDeclaration->location;
             scope->exportedTypeBindings[classDeclaration->name.value] = std::move(initialFun);
 
             classDefinitionLocations[classDeclaration->name.value] = classDeclaration->location;
         }
     }
 
-    if (FFlag::LuauUserTypeFunTypecheck && hasTypeFunction)
-        typeFunctionEnvScope = std::make_shared<Scope>(typeFunctionRuntime->rootScope);
-
     // Additional pass for user-defined type functions to fill in their environments completely
     for (AstStat* stat : block->body)
     {
         if (auto function = stat->as<AstStatTypeFunction>())
         {
-            if (FFlag::LuauUserTypeFunTypecheck)
-            {
-                // Similar to global pre-population, create a binding for each type function in the scope upfront
-                TypeId bt = arena->addType(BlockedType{});
-                typeFunctionEnvScope->bindings[function->name] = Binding{bt, function->location};
-                astTypeFunctionEnvironmentScopes[function] = typeFunctionEnvScope;
-            }
-
             // Find the type function we have already created
             TypeFunctionInstanceType* mainTypeFun = nullptr;
 
@@ -885,60 +843,51 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
                 UserDefinedFunctionData& userFuncData = mainTypeFun->userFuncData;
                 size_t level = 0;
 
-                if (FFlag::LuauUserTypeFunTypecheck)
+                for (Scope* curr = scope.get(); curr; curr = curr->parent.get())
                 {
-                    auto addToEnvironment = [this](UserDefinedFunctionData& userFuncData, ScopePtr scope, const Name& name, TypeId type, size_t level)
+                    for (auto& [name, tf] : curr->privateTypeBindings)
                     {
                         if (userFuncData.environment.find(name))
-                            return;
+                            continue;
 
-                        if (auto ty = get<TypeFunctionInstanceType>(type); ty && ty->userFuncData.definition)
-                        {
+                        if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
                             userFuncData.environment[name] = std::make_pair(ty->userFuncData.definition, level);
-
-                            if (auto it = astTypeFunctionEnvironmentScopes.find(ty->userFuncData.definition))
-                            {
-                                if (auto existing = (*it)->linearSearchForBinding(name, /* traverseScopeChain */ false))
-                                    scope->bindings[ty->userFuncData.definition->name] =
-                                        Binding{existing->typeId, ty->userFuncData.definition->location};
-                            }
-                        }
-                    };
-
-                    for (Scope* curr = scope.get(); curr; curr = curr->parent.get())
-                    {
-                        for (auto& [name, tf] : curr->privateTypeBindings)
-                            addToEnvironment(userFuncData, typeFunctionEnvScope, name, tf.type, level);
-
-                        for (auto& [name, tf] : curr->exportedTypeBindings)
-                            addToEnvironment(userFuncData, typeFunctionEnvScope, name, tf.type, level);
-
-                        level++;
                     }
-                }
-                else
-                {
-                    for (Scope* curr = scope.get(); curr; curr = curr->parent.get())
+
+                    for (auto& [name, tf] : curr->exportedTypeBindings)
                     {
-                        for (auto& [name, tf] : curr->privateTypeBindings)
-                        {
-                            if (userFuncData.environment.find(name))
-                                continue;
+                        if (userFuncData.environment.find(name))
+                            continue;
 
-                            if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
-                                userFuncData.environment[name] = std::make_pair(ty->userFuncData.definition, level);
-                        }
+                        if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
+                            userFuncData.environment[name] = std::make_pair(ty->userFuncData.definition, level);
+                    }
 
-                        for (auto& [name, tf] : curr->exportedTypeBindings)
-                        {
-                            if (userFuncData.environment.find(name))
-                                continue;
+                    level++;
+                }
+            }
+            else if (mainTypeFun)
+            {
+                UserDefinedFunctionData& userFuncData = mainTypeFun->userFuncData;
 
-                            if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
-                                userFuncData.environment[name] = std::make_pair(ty->userFuncData.definition, level);
-                        }
+                for (Scope* curr = scope.get(); curr; curr = curr->parent.get())
+                {
+                    for (auto& [name, tf] : curr->privateTypeBindings)
+                    {
+                        if (userFuncData.environment_DEPRECATED.find(name))
+                            continue;
 
-                        level++;
+                        if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
+                            userFuncData.environment_DEPRECATED[name] = ty->userFuncData.definition;
+                    }
+
+                    for (auto& [name, tf] : curr->exportedTypeBindings)
+                    {
+                        if (userFuncData.environment_DEPRECATED.find(name))
+                            continue;
+
+                        if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
+                            userFuncData.environment_DEPRECATED[name] = ty->userFuncData.definition;
                     }
                 }
             }
@@ -1370,23 +1319,6 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatRepeat* rep
     return ControlFlow::None;
 }
 
-static void propagateDeprecatedAttributeToConstraint(ConstraintV& c, const AstExprFunction* func)
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-    if (GeneralizationConstraint* genConstraint = c.get_if<GeneralizationConstraint>())
-    {
-        genConstraint->hasDeprecatedAttribute = func->hasAttribute(AstAttr::Type::Deprecated);
-    }
-}
-
-static void propagateDeprecatedAttributeToType(TypeId signature, const AstExprFunction* func)
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-    FunctionType* fty = getMutable<FunctionType>(signature);
-    LUAU_ASSERT(fty);
-    fty->isDeprecatedFunction = func->hasAttribute(AstAttr::Type::Deprecated);
-}
-
 ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatLocalFunction* function)
 {
     // Local
@@ -1424,9 +1356,6 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatLocalFuncti
         std::unique_ptr<Constraint> c =
             std::make_unique<Constraint>(constraintScope, function->name->location, GeneralizationConstraint{functionType, sig.signature});
 
-        if (FFlag::LuauDeprecatedAttribute)
-            propagateDeprecatedAttributeToConstraint(c->c, function->func);
-
         Constraint* previous = nullptr;
         forEachConstraint(
             start,
@@ -1450,11 +1379,7 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatLocalFuncti
         module->astTypes[function->func] = functionType;
     }
     else
-    {
         module->astTypes[function->func] = sig.signature;
-        if (FFlag::LuauDeprecatedAttribute)
-            propagateDeprecatedAttributeToType(sig.signature, function->func);
-    }
 
     return ControlFlow::None;
 }
@@ -1495,11 +1420,7 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatFunction* f
 
     TypeId generalizedType = arena->addType(BlockedType{});
     if (sigFullyDefined)
-    {
         emplaceType<BoundType>(asMutable(generalizedType), sig.signature);
-        if (FFlag::LuauDeprecatedAttribute)
-            propagateDeprecatedAttributeToType(sig.signature, function->func);
-    }
     else
     {
         const ScopePtr& constraintScope = sig.signatureScope ? sig.signatureScope : sig.bodyScope;
@@ -1507,9 +1428,6 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatFunction* f
         NotNull<Constraint> c = addConstraint(constraintScope, function->name->location, GeneralizationConstraint{generalizedType, sig.signature});
         getMutable<BlockedType>(generalizedType)->setOwner(c);
 
-        if (FFlag::LuauDeprecatedAttribute)
-            propagateDeprecatedAttributeToConstraint(c->c, function->func);
-
         Constraint* previous = nullptr;
         forEachConstraint(
             start,
@@ -1771,64 +1689,6 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatTypeAlias*
 
 ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatTypeFunction* function)
 {
-    if (!FFlag::LuauUserTypeFunTypecheck)
-        return ControlFlow::None;
-
-    auto scopePtr = astTypeFunctionEnvironmentScopes.find(function);
-    LUAU_ASSERT(scopePtr);
-
-    Checkpoint startCheckpoint = checkpoint(this);
-    FunctionSignature sig = checkFunctionSignature(*scopePtr, function->body, /* expectedType */ std::nullopt);
-
-    // Place this function as a child of the non-type function scope
-    scope->children.push_back(NotNull{sig.signatureScope.get()});
-
-    interiorTypes.push_back(std::vector<TypeId>{});
-    checkFunctionBody(sig.bodyScope, function->body);
-    Checkpoint endCheckpoint = checkpoint(this);
-
-    TypeId generalizedTy = arena->addType(BlockedType{});
-    NotNull<Constraint> gc = addConstraint(
-        sig.signatureScope,
-        function->location,
-        GeneralizationConstraint{
-            generalizedTy, sig.signature, FFlag::LuauTrackInteriorFreeTypesOnScope ? std::vector<TypeId>{} : std::move(interiorTypes.back())
-        }
-    );
-
-    if (FFlag::LuauTrackInteriorFreeTypesOnScope)
-        sig.signatureScope->interiorFreeTypes = std::move(interiorTypes.back());
-
-    getMutable<BlockedType>(generalizedTy)->setOwner(gc);
-    interiorTypes.pop_back();
-
-    Constraint* previous = nullptr;
-    forEachConstraint(
-        startCheckpoint,
-        endCheckpoint,
-        this,
-        [gc, &previous](const ConstraintPtr& constraint)
-        {
-            gc->dependencies.emplace_back(constraint.get());
-
-            if (auto psc = get<PackSubtypeConstraint>(*constraint); psc && psc->returns)
-            {
-                if (previous)
-                    constraint->dependencies.push_back(NotNull{previous});
-
-                previous = constraint.get();
-            }
-        }
-    );
-
-    std::optional<TypeId> existingFunctionTy = (*scopePtr)->lookup(function->name);
-
-    if (!existingFunctionTy)
-        ice->ice("checkAliases did not populate type function name", function->nameLocation);
-
-    if (auto bt = get<BlockedType>(*existingFunctionTy); bt && nullptr == bt->getOwner())
-        emplaceType<BoundType>(asMutable(*existingFunctionTy), generalizedTy);
-
     return ControlFlow::None;
 }
 
@@ -2022,11 +1882,9 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatDeclareFunc
     defn.varargLocation = global->vararg ? std::make_optional(global->varargLocation) : std::nullopt;
     defn.originalNameLocation = global->nameLocation;
 
-    TypeId fnType = arena->addType(FunctionType{TypeLevel{}, std::move(genericTys), std::move(genericTps), paramPack, retPack, defn});
+    TypeId fnType = arena->addType(FunctionType{TypeLevel{}, funScope.get(), std::move(genericTys), std::move(genericTps), paramPack, retPack, defn});
     FunctionType* ftv = getMutable<FunctionType>(fnType);
     ftv->isCheckedFunction = global->isCheckedFunction();
-    if (FFlag::LuauDeprecatedAttribute)
-        ftv->isDeprecatedFunction = global->hasAttribute(AstAttr::Type::Deprecated);
 
     ftv->argNames.reserve(global->paramNames.size);
     for (const auto& el : global->paramNames)
@@ -2194,23 +2052,13 @@ InferencePack ConstraintGenerator::checkPack(const ScopePtr& scope, AstExprCall*
         }
         else if (i < exprArgs.size() - 1 || !(arg->is<AstExprCall>() || arg->is<AstExprVarargs>()))
         {
-            std::optional<TypeId> expectedType = std::nullopt;
-            if (FFlag::LuauPropagateExpectedTypesForCalls && i < expectedTypesForCall.size())
-            {
-                expectedType = expectedTypesForCall[i];
-            }
-            auto [ty, refinement] = check(scope, arg, expectedType, /*forceSingleton*/ false, /*generalize*/ false);
+            auto [ty, refinement] = check(scope, arg, /*expectedType*/ std::nullopt, /*forceSingleton*/ false, /*generalize*/ false);
             args.push_back(ty);
             argumentRefinements.push_back(refinement);
         }
         else
         {
-            std::vector<std::optional<Luau::TypeId>> expectedTypes = {};
-            if (FFlag::LuauPropagateExpectedTypesForCalls && i < expectedTypesForCall.size())
-            {
-                expectedTypes.insert(expectedTypes.end(), expectedTypesForCall.begin() + int(i), expectedTypesForCall.end());
-            }
-            auto [tp, refis] = checkPack(scope, arg, expectedTypes);
+            auto [tp, refis] = checkPack(scope, arg, {});
             argTail = tp;
             argumentRefinements.insert(argumentRefinements.end(), refis.begin(), refis.end());
         }
@@ -2312,7 +2160,7 @@ InferencePack ConstraintGenerator::checkPack(const ScopePtr& scope, AstExprCall*
     // TODO: How do expectedTypes play into this?  Do they?
     TypePackId rets = arena->addTypePack(BlockedTypePack{});
     TypePackId argPack = addTypePack(std::move(args), argTail);
-    FunctionType ftv(TypeLevel{}, argPack, rets, std::nullopt, call->self);
+    FunctionType ftv(TypeLevel{}, scope.get(), argPack, rets, std::nullopt, call->self);
 
     /*
      * To make bidirectional type checking work, we need to solve these constraints in a particular order:
@@ -2379,16 +2227,6 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExpr* expr, std::
         return Inference{builtinTypes->errorRecoveryType()};
     }
 
-    // We may recurse a given expression more than once when checking compound
-    // assignment, so we store and cache expressions here s.t. when we generate
-    // constraints for something like:
-    //
-    //   a[b] += c
-    //
-    // We only solve _one_ set of constraints for `b`.
-    if (FFlag::LuauCacheInferencePerAstExpr && inferredExprCache.contains(expr))
-        return inferredExprCache[expr];
-
     Inference result;
 
     if (auto group = expr->as<AstExprGroup>())
@@ -2441,9 +2279,6 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExpr* expr, std::
         result = Inference{freshType(scope)};
     }
 
-    if (FFlag::LuauCacheInferencePerAstExpr)
-        inferredExprCache[expr] = result;
-
     LUAU_ASSERT(result.ty);
     module->astTypes[expr] = result.ty;
     if (expectedType)
@@ -2483,7 +2318,8 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprConstantBool*
 Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprLocal* local)
 {
     const RefinementKey* key = dfg->getRefinementKey(local);
-    LUAU_ASSERT(key);
+    std::optional<DefId> rvalueDef = dfg->getRValueDefForCompoundAssign(local);
+    LUAU_ASSERT(key || rvalueDef);
 
     std::optional<TypeId> maybeTy;
 
@@ -2491,6 +2327,11 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprLocal* local)
     if (key)
         maybeTy = lookup(scope, local->location, key->def);
 
+    // if the current def doesn't have a type, we might be doing a compound assignment
+    // and therefore might need to look at the rvalue def instead.
+    if (!maybeTy && rvalueDef)
+        maybeTy = lookup(scope, local->location, *rvalueDef);
+
     if (maybeTy)
     {
         TypeId ty = follow(*maybeTy);
@@ -2506,9 +2347,11 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprLocal* local)
 Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprGlobal* global)
 {
     const RefinementKey* key = dfg->getRefinementKey(global);
-    LUAU_ASSERT(key);
+    std::optional<DefId> rvalueDef = dfg->getRValueDefForCompoundAssign(global);
+    LUAU_ASSERT(key || rvalueDef);
 
-    DefId def = key->def;
+    // we'll use whichever of the two definitions we have here.
+    DefId def = key ? key->def : *rvalueDef;
 
     /* prepopulateGlobalScope() has already added all global functions to the environment by this point, so any
      * global that is not already in-scope is definitely an unknown symbol.
@@ -3181,17 +3024,49 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprTable* expr,
 
     if (expectedType)
     {
-        addConstraint(
-            scope,
-            expr->location,
-            TableCheckConstraint{
-                *expectedType,
-                ty,
-                expr,
-                NotNull{&module->astTypes},
-                NotNull{&module->astExpectedTypes},
+        if (FFlag::LuauDeferBidirectionalInferenceForTableAssignment)
+        {
+            addConstraint(
+                scope,
+                expr->location,
+                TableCheckConstraint{
+                    *expectedType,
+                    ty,
+                    expr,
+                    NotNull{&module->astTypes},
+                    NotNull{&module->astExpectedTypes},
+                }
+            );
+        }
+        else
+        {
+            Unifier2 unifier{arena, builtinTypes, NotNull{scope.get()}, ice};
+            Subtyping sp{builtinTypes, arena, simplifier, normalizer, typeFunctionRuntime, ice};
+            std::vector<TypeId> toBlock;
+            // This logic is incomplete as we want to re-run this
+            // _after_ blocked types have resolved, but this
+            // allows us to do some bidirectional inference.
+            toBlock = findBlockedTypesIn(expr, NotNull{&module->astTypes});
+            if (toBlock.empty())
+            {
+                matchLiteralType(
+                    NotNull{&module->astTypes},
+                    NotNull{&module->astExpectedTypes},
+                    builtinTypes,
+                    arena,
+                    NotNull{&unifier},
+                    NotNull{&sp},
+                    *expectedType,
+                    ty,
+                    expr,
+                    toBlock
+                );
+                // The visitor we ran prior should ensure that there are no
+                // blocked types that we would encounter while matching on
+                // this expression.
+                LUAU_ASSERT(toBlock.empty());
             }
-        );
+        }
     }
 
     return Inference{ty};
@@ -3219,7 +3094,7 @@ ConstraintGenerator::FunctionSignature ConstraintGenerator::checkFunctionSignatu
     signatureScope = childScope(fn, parent);
 
     // We need to assign returnType before creating bodyScope so that the
-    // return type gets propagated to bodyScope.
+    // return type gets propogated to bodyScope.
     returnType = freshTypePack(signatureScope);
     signatureScope->returnType = returnType;
 
@@ -3362,7 +3237,7 @@ ConstraintGenerator::FunctionSignature ConstraintGenerator::checkFunctionSignatu
 
     // TODO: Preserve argument names in the function's type.
 
-    FunctionType actualFunction{TypeLevel{}, arena->addTypePack(argTypes, varargPack), returnType};
+    FunctionType actualFunction{TypeLevel{}, parent.get(), arena->addTypePack(argTypes, varargPack), returnType};
     actualFunction.generics = std::move(genericTypes);
     actualFunction.genericPacks = std::move(genericTypePacks);
     actualFunction.argNames = std::move(argNames);
@@ -3599,10 +3474,8 @@ TypeId ConstraintGenerator::resolveFunctionType(
 
     // TODO: FunctionType needs a pointer to the scope so that we know
     // how to quantify/instantiate it.
-    FunctionType ftv{TypeLevel{}, {}, {}, argTypes, returnTypes};
+    FunctionType ftv{TypeLevel{}, scope.get(), {}, {}, argTypes, returnTypes};
     ftv.isCheckedFunction = fn->isCheckedFunction();
-    if (FFlag::LuauDeprecatedAttribute)
-        ftv.isDeprecatedFunction = fn->hasAttribute(AstAttr::Type::Deprecated);
 
     // This replicates the behavior of the appropriate FunctionType
     // constructors.
@@ -3647,80 +3520,37 @@ TypeId ConstraintGenerator::resolveType(const ScopePtr& scope, AstType* ty, bool
         TypeId exprType = check(scope, tof->expr).ty;
         result = exprType;
     }
-    else if (ty->is<AstTypeOptional>())
-    {
-        if (FFlag::LuauAlwaysResolveAstTypes)
-            result = builtinTypes->nilType;
-        else
-            return builtinTypes->nilType;
-    }
     else if (auto unionAnnotation = ty->as<AstTypeUnion>())
     {
-        if (FFlag::LuauAlwaysResolveAstTypes)
+        if (FFlag::LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
         {
             if (unionAnnotation->types.size == 1)
-                result = resolveType(scope, unionAnnotation->types.data[0], inTypeArguments);
-            else
-            {
-                std::vector<TypeId> parts;
-                for (AstType* part : unionAnnotation->types)
-                {
-                    parts.push_back(resolveType(scope, part, inTypeArguments));
-                }
-
-                result = arena->addType(UnionType{parts});
-            }
+                return resolveType(scope, unionAnnotation->types.data[0], inTypeArguments);
         }
-        else
+
+        std::vector<TypeId> parts;
+        for (AstType* part : unionAnnotation->types)
         {
-            if (FFlag::LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
-            {
-                if (unionAnnotation->types.size == 1)
-                    return resolveType(scope, unionAnnotation->types.data[0], inTypeArguments);
-            }
-
-            std::vector<TypeId> parts;
-            for (AstType* part : unionAnnotation->types)
-            {
-                parts.push_back(resolveType(scope, part, inTypeArguments));
-            }
-
-            result = arena->addType(UnionType{parts});
+            parts.push_back(resolveType(scope, part, inTypeArguments));
         }
+
+        result = arena->addType(UnionType{parts});
     }
     else if (auto intersectionAnnotation = ty->as<AstTypeIntersection>())
     {
-        if (FFlag::LuauAlwaysResolveAstTypes)
+        if (FFlag::LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
         {
             if (intersectionAnnotation->types.size == 1)
-                result = resolveType(scope, intersectionAnnotation->types.data[0], inTypeArguments);
-            else
-            {
-                std::vector<TypeId> parts;
-                for (AstType* part : intersectionAnnotation->types)
-                {
-                    parts.push_back(resolveType(scope, part, inTypeArguments));
-                }
-
-                result = arena->addType(IntersectionType{parts});
-            }
+                return resolveType(scope, intersectionAnnotation->types.data[0], inTypeArguments);
         }
-        else
+
+        std::vector<TypeId> parts;
+        for (AstType* part : intersectionAnnotation->types)
         {
-            if (FFlag::LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
-            {
-                if (intersectionAnnotation->types.size == 1)
-                    return resolveType(scope, intersectionAnnotation->types.data[0], inTypeArguments);
-            }
-
-            std::vector<TypeId> parts;
-            for (AstType* part : intersectionAnnotation->types)
-            {
-                parts.push_back(resolveType(scope, part, inTypeArguments));
-            }
-
-            result = arena->addType(IntersectionType{parts});
+            parts.push_back(resolveType(scope, part, inTypeArguments));
         }
+
+        result = arena->addType(IntersectionType{parts});
     }
     else if (auto typeGroupAnnotation = ty->as<AstTypeGroup>())
     {
@@ -4052,18 +3882,9 @@ struct GlobalPrepopulator : AstVisitor
 void ConstraintGenerator::prepopulateGlobalScopeForFragmentTypecheck(const ScopePtr& globalScope, const ScopePtr& resumeScope, AstStatBlock* program)
 {
     FragmentTypeCheckGlobalPrepopulator gp{NotNull{globalScope.get()}, NotNull{resumeScope.get()}, dfg, arena};
-
     if (prepareModuleScope)
         prepareModuleScope(module->name, resumeScope);
-
     program->visit(&gp);
-
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // Handle type function globals as well, without preparing a module scope since they have a separate environment
-        GlobalPrepopulator tfgp{NotNull{typeFunctionRuntime->rootScope.get()}, arena, dfg};
-        program->visit(&tfgp);
-    }
 }
 
 void ConstraintGenerator::prepopulateGlobalScope(const ScopePtr& globalScope, AstStatBlock* program)
@@ -4074,13 +3895,6 @@ void ConstraintGenerator::prepopulateGlobalScope(const ScopePtr& globalScope, As
         prepareModuleScope(module->name, globalScope);
 
     program->visit(&gp);
-
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // Handle type function globals as well, without preparing a module scope since they have a separate environment
-        GlobalPrepopulator tfgp{NotNull{typeFunctionRuntime->rootScope.get()}, arena, dfg};
-        program->visit(&tfgp);
-    }
 }
 
 bool ConstraintGenerator::recordPropertyAssignment(TypeId ty)

Analysis/src/ConstraintSolver.cpp

@@ -35,13 +35,9 @@ LUAU_FASTINTVARIABLE(LuauSolverRecursionLimit, 500)
 LUAU_FASTFLAGVARIABLE(DebugLuauEqSatSimplification)
 LUAU_FASTFLAG(LuauTrackInteriorFreeTypesOnScope)
 LUAU_FASTFLAGVARIABLE(LuauTrackInteriorFreeTablesOnScope)
-LUAU_FASTFLAGVARIABLE(LuauHasPropProperBlock)
+LUAU_FASTFLAGVARIABLE(LuauPrecalculateMutatedFreeTypes2)
 LUAU_FASTFLAGVARIABLE(DebugLuauGreedyGeneralization)
 LUAU_FASTFLAG(LuauSearchForRefineableType)
-LUAU_FASTFLAG(LuauDeprecatedAttribute)
-LUAU_FASTFLAG(LuauBidirectionalInferenceCollectIndexerTypes)
-LUAU_FASTFLAG(LuauNewTypeFunReductionChecks2)
-LUAU_FASTFLAGVARIABLE(LuauTrackInferredFunctionTypeFromCall)
 
 namespace Luau
 {
@@ -361,19 +357,32 @@ ConstraintSolver::ConstraintSolver(
     {
         unsolvedConstraints.emplace_back(c);
 
-        auto maybeMutatedTypesPerConstraint = c->getMaybeMutatedFreeTypes();
-        for (auto ty : maybeMutatedTypesPerConstraint)
+        if (FFlag::LuauPrecalculateMutatedFreeTypes2)
         {
-            auto [refCount, _] = unresolvedConstraints.try_insert(ty, 0);
-            refCount += 1;
-
-            if (FFlag::DebugLuauGreedyGeneralization)
+            auto maybeMutatedTypesPerConstraint = c->getMaybeMutatedFreeTypes();
+            for (auto ty : maybeMutatedTypesPerConstraint)
             {
-                auto [it, fresh] = mutatedFreeTypeToConstraint.try_emplace(ty, DenseHashSet<const Constraint*>{nullptr});
-                it->second.insert(c.get());
+                auto [refCount, _] = unresolvedConstraints.try_insert(ty, 0);
+                refCount += 1;
+
+                if (FFlag::DebugLuauGreedyGeneralization)
+                {
+                    auto [it, fresh] = mutatedFreeTypeToConstraint.try_emplace(ty, DenseHashSet<const Constraint*>{nullptr});
+                    it->second.insert(c.get());
+                }
+            }
+            maybeMutatedFreeTypes.emplace(c, maybeMutatedTypesPerConstraint);
+        }
+        else
+        {
+            // initialize the reference counts for the free types in this constraint.
+            for (auto ty : c->getMaybeMutatedFreeTypes())
+            {
+                // increment the reference count for `ty`
+                auto [refCount, _] = unresolvedConstraints.try_insert(ty, 0);
+                refCount += 1;
             }
         }
-        maybeMutatedFreeTypes.emplace(c, maybeMutatedTypesPerConstraint);
 
 
         for (NotNull<const Constraint> dep : c->dependencies)
@@ -464,24 +473,48 @@ void ConstraintSolver::run()
                 unblock(c);
                 unsolvedConstraints.erase(unsolvedConstraints.begin() + ptrdiff_t(i));
 
-                const auto maybeMutated = maybeMutatedFreeTypes.find(c);
-                if (maybeMutated != maybeMutatedFreeTypes.end())
+                if (FFlag::LuauPrecalculateMutatedFreeTypes2)
                 {
-                    DenseHashSet<TypeId> seen{nullptr};
-                    for (auto ty : maybeMutated->second)
+                    const auto maybeMutated = maybeMutatedFreeTypes.find(c);
+                    if (maybeMutated != maybeMutatedFreeTypes.end())
                     {
-                        // There is a high chance that this type has been rebound
-                        // across blocked types, rebound free types, pending
-                        // expansion types, etc, so we need to follow it.
-                        ty = follow(ty);
-
-                        if (FFlag::DebugLuauGreedyGeneralization)
+                        DenseHashSet<TypeId> seen{nullptr};
+                        for (auto ty : maybeMutated->second)
                         {
-                            if (seen.contains(ty))
-                                continue;
-                            seen.insert(ty);
-                        }
+                            // There is a high chance that this type has been rebound
+                            // across blocked types, rebound free types, pending
+                            // expansion types, etc, so we need to follow it.
+                            ty = follow(ty);
 
+                            if (FFlag::DebugLuauGreedyGeneralization)
+                            {
+                                if (seen.contains(ty))
+                                    continue;
+                                seen.insert(ty);
+                            }
+
+                            size_t& refCount = unresolvedConstraints[ty];
+                            if (refCount > 0)
+                                refCount -= 1;
+
+                            // We have two constraints that are designed to wait for the
+                            // refCount on a free type to be equal to 1: the
+                            // PrimitiveTypeConstraint and ReduceConstraint. We
+                            // therefore wake any constraint waiting for a free type's
+                            // refcount to be 1 or 0.
+                            if (refCount <= 1)
+                                unblock(ty, Location{});
+
+                            if (FFlag::DebugLuauGreedyGeneralization && refCount == 0)
+                                generalizeOneType(ty);
+                        }
+                    }
+                }
+                else
+                {
+                    // decrement the referenced free types for this constraint if we dispatched successfully!
+                    for (auto ty : c->getMaybeMutatedFreeTypes())
+                    {
                         size_t& refCount = unresolvedConstraints[ty];
                         if (refCount > 0)
                             refCount -= 1;
@@ -493,9 +526,6 @@ void ConstraintSolver::run()
                         // refcount to be 1 or 0.
                         if (refCount <= 1)
                             unblock(ty, Location{});
-
-                        if (FFlag::DebugLuauGreedyGeneralization && refCount == 0)
-                            generalizeOneType(ty);
                     }
                 }
 
@@ -595,6 +625,14 @@ bool ConstraintSolver::isDone() const
 
 struct TypeSearcher : TypeVisitor
 {
+    enum struct Polarity: uint8_t
+    {
+        None = 0b00,
+        Positive = 0b01,
+        Negative = 0b10,
+        Mixed = 0b11,
+    };
+
     TypeId needle;
     Polarity current = Polarity::Positive;
 
@@ -710,12 +748,12 @@ void ConstraintSolver::generalizeOneType(TypeId ty)
 
         switch (ts.result)
         {
-            case Polarity::None:
+            case TypeSearcher::Polarity::None:
                 asMutable(ty)->reassign(Type{BoundType{upperBound}});
                 break;
 
-            case Polarity::Negative:
-            case Polarity::Mixed:
+            case TypeSearcher::Polarity::Negative:
+            case TypeSearcher::Polarity::Mixed:
                 if (get<UnknownType>(upperBound) && ts.count > 1)
                 {
                     asMutable(ty)->reassign(Type{GenericType{tyScope}});
@@ -725,17 +763,15 @@ void ConstraintSolver::generalizeOneType(TypeId ty)
                     asMutable(ty)->reassign(Type{BoundType{upperBound}});
                 break;
 
-            case Polarity::Positive:
-                if (get<UnknownType>(lowerBound) && ts.count > 1)
-                {
-                    asMutable(ty)->reassign(Type{GenericType{tyScope}});
-                    function->generics.emplace_back(ty);
-                }
-                else
-                    asMutable(ty)->reassign(Type{BoundType{lowerBound}});
-                break;
-            default:
-                LUAU_ASSERT(!"Unreachable");
+            case TypeSearcher::Polarity::Positive:
+            if (get<UnknownType>(lowerBound) && ts.count > 1)
+            {
+                asMutable(ty)->reassign(Type{GenericType{tyScope}});
+                function->generics.emplace_back(ty);
+            }
+            else
+                asMutable(ty)->reassign(Type{BoundType{lowerBound}});
+            break;
         }
     }
 }
@@ -882,15 +918,6 @@ bool ConstraintSolver::tryDispatch(const GeneralizationConstraint& c, NotNull<co
             bind(constraint, generalizedType, *generalizedTy);
         else
             unify(constraint, generalizedType, *generalizedTy);
-
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-            if (FunctionType* fty = getMutable<FunctionType>(follow(generalizedType)))
-            {
-                if (c.hasDeprecatedAttribute)
-                    fty->isDeprecatedFunction = true;
-            }
-        }
     }
     else
     {
@@ -904,12 +931,12 @@ bool ConstraintSolver::tryDispatch(const GeneralizationConstraint& c, NotNull<co
         // clang-tidy doesn't understand this is safe.
         if (constraint->scope->interiorFreeTypes)
             for (TypeId ty : *constraint->scope->interiorFreeTypes) // NOLINT(bugprone-unchecked-optional-access)
-                generalize(NotNull{arena}, builtinTypes, constraint->scope, generalizedTypes, ty);
+                generalize(NotNull{arena}, builtinTypes, constraint->scope, generalizedTypes, ty, /* avoidSealingTables */ false);
     }
     else
     {
         for (TypeId ty : c.interiorTypes)
-            generalize(NotNull{arena}, builtinTypes, constraint->scope, generalizedTypes, ty);
+            generalize(NotNull{arena}, builtinTypes, constraint->scope, generalizedTypes, ty, /* avoidSealingTables */ false);
     }
 
 
@@ -1483,7 +1510,7 @@ bool ConstraintSolver::tryDispatch(const FunctionCallConstraint& c, NotNull<cons
     if (status == OverloadResolver::Analysis::Ok)
         overloadToUse = overload;
 
-    TypeId inferredTy = arena->addType(FunctionType{TypeLevel{}, argsPack, c.result});
+    TypeId inferredTy = arena->addType(FunctionType{TypeLevel{}, constraint->scope.get(), argsPack, c.result});
     Unifier2 u2{NotNull{arena}, builtinTypes, constraint->scope, NotNull{&iceReporter}};
 
     const bool occursCheckPassed = u2.unify(overloadToUse, inferredTy);
@@ -1518,11 +1545,6 @@ bool ConstraintSolver::tryDispatch(const FunctionCallConstraint& c, NotNull<cons
     queuer.traverse(overloadToUse);
     queuer.traverse(inferredTy);
 
-    // This can potentially contain free types if the return type of
-    // `inferredTy` is never unified elsewhere.
-    if (FFlag::LuauTrackInteriorFreeTypesOnScope && FFlag::LuauTrackInferredFunctionTypeFromCall)
-        trackInteriorFreeType(constraint->scope, inferredTy);
-
     unblock(c.result, constraint->location);
 
     return true;
@@ -1536,43 +1558,6 @@ static AstExpr* unwrapGroup(AstExpr* expr)
     return expr;
 }
 
-struct ContainsGenerics : public TypeOnceVisitor
-{
-    DenseHashSet<const void*> generics{nullptr};
-
-    bool found = false;
-
-    bool visit(TypeId ty) override
-    {
-        return !found;
-    }
-
-    bool visit(TypeId ty, const GenericType&) override
-    {
-        found |= generics.contains(ty);
-        return true;
-    }
-
-    bool visit(TypeId ty, const TypeFunctionInstanceType&) override
-    {
-        return !found;
-    }
-
-    bool visit(TypePackId tp, const GenericTypePack&) override
-    {
-        found |= generics.contains(tp);
-        return !found;
-    }
-
-    bool hasGeneric(TypeId ty)
-    {
-        traverse(ty);
-        auto ret = found;
-        found = false;
-        return ret;
-    }
-};
-
 bool ConstraintSolver::tryDispatch(const FunctionCheckConstraint& c, NotNull<const Constraint> constraint)
 {
     TypeId fn = follow(c.fn);
@@ -1615,49 +1600,36 @@ bool ConstraintSolver::tryDispatch(const FunctionCheckConstraint& c, NotNull<con
     DenseHashMap<TypeId, TypeId> replacements{nullptr};
     DenseHashMap<TypePackId, TypePackId> replacementPacks{nullptr};
 
-    ContainsGenerics containsGenerics;
-
     for (auto generic : ftv->generics)
-    {
         replacements[generic] = builtinTypes->unknownType;
-        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-            containsGenerics.generics.insert(generic);
-    }
 
     for (auto genericPack : ftv->genericPacks)
-    {
         replacementPacks[genericPack] = builtinTypes->unknownTypePack;
-        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-            containsGenerics.generics.insert(genericPack);
-    }
 
     // If the type of the function has generics, we don't actually want to push any of the generics themselves
     // into the argument types as expected types because this creates an unnecessary loop. Instead, we want to
     // replace these types with `unknown` (and `...unknown`) to keep any structure but not create the cycle.
-    if (!FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
+    if (!replacements.empty() || !replacementPacks.empty())
     {
-        if (!replacements.empty() || !replacementPacks.empty())
+        Replacer replacer{arena, std::move(replacements), std::move(replacementPacks)};
+
+        std::optional<TypeId> res = replacer.substitute(fn);
+        if (res)
         {
-            Replacer replacer{arena, std::move(replacements), std::move(replacementPacks)};
-
-            std::optional<TypeId> res = replacer.substitute(fn);
-            if (res)
+            if (*res != fn)
             {
-                if (*res != fn)
-                {
-                    FunctionType* ftvMut = getMutable<FunctionType>(*res);
-                    LUAU_ASSERT(ftvMut);
-                    ftvMut->generics.clear();
-                    ftvMut->genericPacks.clear();
-                }
-
-                fn = *res;
-                ftv = get<FunctionType>(*res);
-                LUAU_ASSERT(ftv);
-
-                // we've potentially copied type functions here, so we need to reproduce their reduce constraint.
-                reproduceConstraints(constraint->scope, constraint->location, replacer);
+                FunctionType* ftvMut = getMutable<FunctionType>(*res);
+                LUAU_ASSERT(ftvMut);
+                ftvMut->generics.clear();
+                ftvMut->genericPacks.clear();
             }
+
+            fn = *res;
+            ftv = get<FunctionType>(*res);
+            LUAU_ASSERT(ftv);
+
+            // we've potentially copied type functions here, so we need to reproduce their reduce constraint.
+            reproduceConstraints(constraint->scope, constraint->location, replacer);
         }
     }
 
@@ -1676,10 +1648,6 @@ bool ConstraintSolver::tryDispatch(const FunctionCheckConstraint& c, NotNull<con
 
         (*c.astExpectedTypes)[expr] = expectedArgTy;
 
-        // Generic types are skipped over entirely, for now.
-        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes && containsGenerics.hasGeneric(expectedArgTy))
-            continue;
-
         const FunctionType* expectedLambdaTy = get<FunctionType>(expectedArgTy);
         const FunctionType* lambdaTy = get<FunctionType>(actualArgTy);
         const AstExprFunction* lambdaExpr = expr->as<AstExprFunction>();
@@ -1784,16 +1752,8 @@ bool ConstraintSolver::tryDispatch(const HasPropConstraint& c, NotNull<const Con
     LUAU_ASSERT(get<BlockedType>(resultType));
     LUAU_ASSERT(canMutate(resultType, constraint));
 
-    if (FFlag::LuauHasPropProperBlock)
-    {
-        if (isBlocked(subjectType))
-            return block(subjectType, constraint);
-    }
-    else
-    {
-        if (isBlocked(subjectType) || get<PendingExpansionType>(subjectType) || get<TypeFunctionInstanceType>(subjectType))
-            return block(subjectType, constraint);
-    }
+    if (isBlocked(subjectType) || get<PendingExpansionType>(subjectType) || get<TypeFunctionInstanceType>(subjectType))
+        return block(subjectType, constraint);
 
     if (const TableType* subjectTable = getTableType(subjectType))
     {
@@ -2399,18 +2359,11 @@ bool ConstraintSolver::tryDispatch(const ReduceConstraint& c, NotNull<const Cons
     for (TypePackId r : result.reducedPacks)
         unblock(r, constraint->location);
 
-    if (FFlag::LuauNewTypeFunReductionChecks2)
-    {
-        for (TypeId ity : result.irreducibleTypes)
-            uninhabitedTypeFunctions.insert(ity);
-    }
-
     bool reductionFinished = result.blockedTypes.empty() && result.blockedPacks.empty();
 
     ty = follow(ty);
-
     // If we couldn't reduce this type function, stick it in the set!
-    if (get<TypeFunctionInstanceType>(ty) && (!FFlag::LuauNewTypeFunReductionChecks2 || !result.irreducibleTypes.find(ty)))
+    if (get<TypeFunctionInstanceType>(ty))
         typeFunctionsToFinalize[ty] = constraint;
 
     if (force || reductionFinished)
@@ -3330,7 +3283,7 @@ void ConstraintSolver::shiftReferences(TypeId source, TypeId target)
     }
 }
 
-std::optional<TypeId> ConstraintSolver::generalizeFreeType(NotNull<Scope> scope, TypeId type)
+std::optional<TypeId> ConstraintSolver::generalizeFreeType(NotNull<Scope> scope, TypeId type, bool avoidSealingTables)
 {
     TypeId t = follow(type);
     if (get<FreeType>(t))
@@ -3345,7 +3298,7 @@ std::optional<TypeId> ConstraintSolver::generalizeFreeType(NotNull<Scope> scope,
         // that until all constraint generation is complete.
     }
 
-    return generalize(NotNull{arena}, builtinTypes, scope, generalizedTypes, type);
+    return generalize(NotNull{arena}, builtinTypes, scope, generalizedTypes, type, avoidSealingTables);
 }
 
 bool ConstraintSolver::hasUnresolvedConstraints(TypeId ty)

Analysis/src/DataFlowGraph.cpp

@@ -13,22 +13,32 @@
 
 LUAU_FASTFLAG(DebugLuauFreezeArena)
 LUAU_FASTFLAG(LuauSolverV2)
-LUAU_FASTFLAGVARIABLE(LuauPreprocessTypestatedArgument)
-LUAU_FASTFLAGVARIABLE(LuauDfgScopeStackTrueReset)
 
 namespace Luau
 {
 
 bool doesCallError(const AstExprCall* call); // TypeInfer.cpp
 
+struct ReferencedDefFinder : public AstVisitor
+{
+    bool visit(AstExprLocal* local) override
+    {
+        referencedLocalDefs.push_back(local->local);
+        return true;
+    }
+    // ast defs is just a mapping from expr -> def in general
+    // will get built up by the dfg builder
+
+    // localDefs, we need to copy over
+    std::vector<AstLocal*> referencedLocalDefs;
+};
+
 struct PushScope
 {
     ScopeStack& stack;
-    size_t previousSize;
 
     PushScope(ScopeStack& stack, DfgScope* scope)
         : stack(stack)
-        , previousSize(stack.size())
     {
         // `scope` should never be `nullptr` here.
         LUAU_ASSERT(scope);
@@ -37,18 +47,7 @@ struct PushScope
 
     ~PushScope()
     {
-        if (FFlag::LuauDfgScopeStackTrueReset)
-        {
-            // If somehow this stack has _shrunk_ to be smaller than we expect,
-            // something very strange has happened.
-            LUAU_ASSERT(stack.size() > previousSize);
-            while (stack.size() > previousSize)
-                stack.pop_back();
-        }
-        else
-        {
-            stack.pop_back();
-        }
+        stack.pop_back();
     }
 };
 
@@ -83,6 +82,12 @@ std::optional<DefId> DataFlowGraph::getDefOptional(const AstExpr* expr) const
     return NotNull{*def};
 }
 
+std::optional<DefId> DataFlowGraph::getRValueDefForCompoundAssign(const AstExpr* expr) const
+{
+    auto def = compoundAssignDefs.find(expr);
+    return def ? std::optional<DefId>(*def) : std::nullopt;
+}
+
 DefId DataFlowGraph::getDef(const AstLocal* local) const
 {
     auto def = localDefs.find(local);
@@ -873,12 +878,6 @@ DataFlowResult DataFlowGraphBuilder::visitExpr(AstExprCall* c)
 {
     visitExpr(c->func);
 
-    if (FFlag::LuauPreprocessTypestatedArgument)
-    {
-        for (AstExpr* arg : c->args)
-            visitExpr(arg);
-    }
-
     if (shouldTypestateForFirstArgument(*c) && c->args.size > 1 && isLValue(*c->args.begin()))
     {
         AstExpr* firstArg = *c->args.begin();
@@ -909,11 +908,8 @@ DataFlowResult DataFlowGraphBuilder::visitExpr(AstExprCall* c)
         visitLValue(firstArg, def);
     }
 
-    if (!FFlag::LuauPreprocessTypestatedArgument)
-    {
-        for (AstExpr* arg : c->args)
-            visitExpr(arg);
-    }
+    for (AstExpr* arg : c->args)
+        visitExpr(arg);
 
     // We treat function calls as "subscripted" as they could potentially
     // return a subscripted value, consider:
@@ -1172,8 +1168,6 @@ void DataFlowGraphBuilder::visitType(AstType* t)
         return visitType(f);
     else if (auto tyof = t->as<AstTypeTypeof>())
         return visitType(tyof);
-    else if (auto o = t->as<AstTypeOptional>())
-        return;
     else if (auto u = t->as<AstTypeUnion>())
         return visitType(u);
     else if (auto i = t->as<AstTypeIntersection>())

Analysis/src/EmbeddedBuiltinDefinitions.cpp

@@ -1,6 +1,8 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #include "Luau/BuiltinDefinitions.h"
 
+LUAU_FASTFLAGVARIABLE(LuauDebugInfoDefn)
+
 namespace Luau
 {
 
@@ -213,6 +215,15 @@ declare debug: {
 
 )BUILTIN_SRC";
 
+static const std::string kBuiltinDefinitionDebugSrc_DEPRECATED = R"BUILTIN_SRC(
+
+declare debug: {
+    info: (<R...>(thread: thread, level: number, options: string) -> R...) & (<R...>(level: number, options: string) -> R...) & (<A..., R1..., R2...>(func: (A...) -> R1..., options: string) -> R2...),
+    traceback: ((message: string?, level: number?) -> string) & ((thread: thread, message: string?, level: number?) -> string),
+}
+
+)BUILTIN_SRC";
+
 static const std::string kBuiltinDefinitionUtf8Src = R"BUILTIN_SRC(
 
 declare utf8: {
@@ -298,7 +309,7 @@ std::string getBuiltinDefinitionSource()
     result += kBuiltinDefinitionOsSrc;
     result += kBuiltinDefinitionCoroutineSrc;
     result += kBuiltinDefinitionTableSrc;
-    result += kBuiltinDefinitionDebugSrc;
+    result += FFlag::LuauDebugInfoDefn ? kBuiltinDefinitionDebugSrc : kBuiltinDefinitionDebugSrc_DEPRECATED;
     result += kBuiltinDefinitionUtf8Src;
     result += kBuiltinDefinitionBufferSrc;
     result += kBuiltinDefinitionVectorSrc;
@@ -306,83 +317,4 @@ std::string getBuiltinDefinitionSource()
     return result;
 }
 
-// TODO: split into separate tagged unions when the new solver can appropriately handle that.
-static const std::string kBuiltinDefinitionTypesSrc = R"BUILTIN_SRC(
-
-export type type = {
-    tag: "nil" | "unknown" | "never" | "any" | "boolean" | "number" | "string" | "buffer" | "thread" |
-         "singleton" | "negation" | "union" | "intesection" | "table" | "function" | "class" | "generic",
-
-    is: (self: type, arg: string) -> boolean,
-
-    -- for singleton type
-    value: (self: type) -> (string | boolean | nil),
-
-    -- for negation type
-    inner: (self: type) -> type,
-
-    -- for union and intersection types
-    components: (self: type) -> {type},
-
-    -- for table type
-    setproperty: (self: type, key: type, value: type?) -> (),
-    setreadproperty: (self: type, key: type, value: type?) -> (),
-    setwriteproperty: (self: type, key: type, value: type?) -> (),
-    readproperty: (self: type, key: type) -> type?,
-    writeproperty: (self: type, key: type) -> type?,
-    properties: (self: type) -> { [type]: { read: type?, write: type? } },
-    setindexer: (self: type, index: type, result: type) -> (),
-    setreadindexer: (self: type, index: type, result: type) -> (),
-    setwriteindexer: (self: type, index: type, result: type) -> (),
-    indexer: (self: type) -> { index: type, readresult: type, writeresult: type }?,
-    readindexer: (self: type) -> { index: type, result: type }?,
-    writeindexer: (self: type) -> { index: type, result: type }?,
-    setmetatable: (self: type, arg: type) -> (),
-    metatable: (self: type) -> type?,
-
-    -- for function type
-    setparameters: (self: type, head: {type}?, tail: type?) -> (),
-    parameters: (self: type) -> { head: {type}?, tail: type? },
-    setreturns: (self: type, head: {type}?, tail: type? ) -> (),
-    returns: (self: type) -> { head: {type}?, tail: type? },
-    setgenerics: (self: type, {type}?) -> (),
-    generics: (self: type) -> {type},
-
-    -- for class type
-    -- 'properties', 'metatable', 'indexer', 'readindexer' and 'writeindexer' are shared with table type
-    readparent: (self: type) -> type?,
-    writeparent: (self: type) -> type?,
-
-    -- for generic type
-    name: (self: type) -> string?,
-    ispack: (self: type) -> boolean,
-}
-
-declare types: {
-    unknown: type,
-    never: type,
-    any: type,
-    boolean: type,
-    number: type,
-    string: type,
-    thread: type,
-    buffer: type,
-
-    singleton: @checked (arg: string | boolean | nil) -> type,
-    generic: @checked (name: string, ispack: boolean?) -> type,
-    negationof: @checked (arg: type) -> type,
-    unionof: @checked (...type) -> type,
-    intersectionof: @checked (...type) -> type,
-    newtable: @checked (props: {[type]: type} | {[type]: { read: type, write: type } } | nil, indexer: { index: type, readresult: type, writeresult: type }?, metatable: type?) -> type,
-    newfunction: @checked (parameters: { head: {type}?, tail: type? }?, returns: { head: {type}?, tail: type? }?, generics: {type}?) -> type,
-    copy: @checked (arg: type) -> type,
-}
-
-)BUILTIN_SRC";
-
-std::string getTypeFunctionDefinitionSource()
-{
-    return kBuiltinDefinitionTypesSrc;
-}
-
 } // namespace Luau

Analysis/src/Error.cpp

@@ -8,7 +8,6 @@
 #include "Luau/StringUtils.h"
 #include "Luau/ToString.h"
 #include "Luau/Type.h"
-#include "Luau/TypeChecker2.h"
 #include "Luau/TypeFunction.h"
 
 #include <optional>
@@ -18,7 +17,6 @@
 #include <unordered_set>
 
 LUAU_FASTINTVARIABLE(LuauIndentTypeMismatchMaxTypeLength, 10)
-LUAU_FASTFLAG(LuauNonStrictFuncDefErrorFix)
 
 static std::string wrongNumberOfArgsString(
     size_t expectedCount,
@@ -118,10 +116,7 @@ struct ErrorConverter
             size_t luauIndentTypeMismatchMaxTypeLength = size_t(FInt::LuauIndentTypeMismatchMaxTypeLength);
             if (givenType.length() <= luauIndentTypeMismatchMaxTypeLength || wantedType.length() <= luauIndentTypeMismatchMaxTypeLength)
                 return "Type " + given + " could not be converted into " + wanted;
-            if (FFlag::LuauImproveTypePathsInErrors)
-                return "Type\n\t" + given + "\ncould not be converted into\n\t" + wanted;
-            else
-                return "Type\n    " + given + "\ncould not be converted into\n    " + wanted;
+            return "Type\n    " + given + "\ncould not be converted into\n    " + wanted;
         };
 
         if (givenTypeName == wantedTypeName)
@@ -756,15 +751,8 @@ struct ErrorConverter
 
     std::string operator()(const NonStrictFunctionDefinitionError& e) const
     {
-        if (FFlag::LuauNonStrictFuncDefErrorFix && e.functionName.empty())
-        {
-            return "Argument " + e.argument + " with type '" + toString(e.argumentType) + "' is used in a way that will run time error";
-        }
-        else
-        {
-            return "Argument " + e.argument + " with type '" + toString(e.argumentType) + "' in function '" + e.functionName +
-                   "' is used in a way that will run time error";
-        }
+        return "Argument " + e.argument + " with type '" + toString(e.argumentType) + "' in function '" + e.functionName +
+               "' is used in a way that will run time error";
     }
 
     std::string operator()(const PropertyAccessViolation& e) const

Analysis/src/Frontend.cpp

@@ -1,6 +1,7 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #include "Luau/Frontend.h"
 
+#include "Luau/AnyTypeSummary.h"
 #include "Luau/BuiltinDefinitions.h"
 #include "Luau/Clone.h"
 #include "Luau/Common.h"
@@ -39,7 +40,6 @@ LUAU_FASTINT(LuauTarjanChildLimit)
 LUAU_FASTFLAG(LuauInferInNoCheckMode)
 LUAU_FASTFLAGVARIABLE(LuauKnowsTheDataModel3)
 LUAU_FASTFLAG(LuauSolverV2)
-LUAU_DYNAMIC_FASTFLAGVARIABLE(LuauRethrowKnownExceptions, false)
 LUAU_FASTFLAGVARIABLE(DebugLuauLogSolverToJson)
 LUAU_FASTFLAGVARIABLE(DebugLuauLogSolverToJsonFile)
 LUAU_FASTFLAGVARIABLE(DebugLuauForbidInternalTypes)
@@ -47,8 +47,13 @@ LUAU_FASTFLAGVARIABLE(DebugLuauForceStrictMode)
 LUAU_FASTFLAGVARIABLE(DebugLuauForceNonStrictMode)
 LUAU_DYNAMIC_FASTFLAGVARIABLE(LuauRunCustomModuleChecks, false)
 
+LUAU_FASTFLAGVARIABLE(LuauModuleHoldsAstRoot)
+
+LUAU_FASTFLAGVARIABLE(LuauFixMultithreadTypecheck)
+
+LUAU_FASTFLAG(StudioReportLuauAny2)
+
 LUAU_FASTFLAGVARIABLE(LuauSelectivelyRetainDFGArena)
-LUAU_FASTFLAG(LuauTypeFunResultInAutocomplete)
 
 namespace Luau
 {
@@ -456,6 +461,20 @@ CheckResult Frontend::check(const ModuleName& name, std::optional<FrontendOption
 
         if (item.name == name)
             checkResult.lintResult = item.module->lintResult;
+
+        if (FFlag::StudioReportLuauAny2 && item.options.retainFullTypeGraphs)
+        {
+            if (item.module)
+            {
+                const SourceModule& sourceModule = *item.sourceModule;
+                if (sourceModule.mode == Luau::Mode::Strict)
+                {
+                    item.module->ats.root = toString(sourceModule.root);
+                }
+                item.module->ats.rootSrc = sourceModule.root;
+                item.module->ats.traverse(item.module.get(), sourceModule.root, NotNull{&builtinTypes_});
+            }
+        }
     }
 
     return checkResult;
@@ -477,6 +496,11 @@ std::vector<ModuleName> Frontend::checkQueuedModules(
     std::function<bool(size_t done, size_t total)> progress
 )
 {
+    if (!FFlag::LuauFixMultithreadTypecheck)
+    {
+        return checkQueuedModules_DEPRECATED(optionOverride, executeTask, progress);
+    }
+
     FrontendOptions frontendOptions = optionOverride.value_or(options);
     if (FFlag::LuauSolverV2)
         frontendOptions.forAutocomplete = false;
@@ -661,6 +685,247 @@ std::vector<ModuleName> Frontend::checkQueuedModules(
     return checkedModules;
 }
 
+std::vector<ModuleName> Frontend::checkQueuedModules_DEPRECATED(
+    std::optional<FrontendOptions> optionOverride,
+    std::function<void(std::function<void()> task)> executeTask,
+    std::function<bool(size_t done, size_t total)> progress
+)
+{
+    LUAU_ASSERT(!FFlag::LuauFixMultithreadTypecheck);
+
+    FrontendOptions frontendOptions = optionOverride.value_or(options);
+    if (FFlag::LuauSolverV2)
+        frontendOptions.forAutocomplete = false;
+
+    // By taking data into locals, we make sure queue is cleared at the end, even if an ICE or a different exception is thrown
+    std::vector<ModuleName> currModuleQueue;
+    std::swap(currModuleQueue, moduleQueue);
+
+    DenseHashSet<Luau::ModuleName> seen{{}};
+    std::vector<BuildQueueItem> buildQueueItems;
+
+    for (const ModuleName& name : currModuleQueue)
+    {
+        if (seen.contains(name))
+            continue;
+
+        if (!isDirty(name, frontendOptions.forAutocomplete))
+        {
+            seen.insert(name);
+            continue;
+        }
+
+        std::vector<ModuleName> queue;
+        bool cycleDetected = parseGraph(
+            queue,
+            name,
+            frontendOptions.forAutocomplete,
+            [&seen](const ModuleName& name)
+            {
+                return seen.contains(name);
+            }
+        );
+
+        addBuildQueueItems(buildQueueItems, queue, cycleDetected, seen, frontendOptions);
+    }
+
+    if (buildQueueItems.empty())
+        return {};
+
+    // We need a mapping from modules to build queue slots
+    std::unordered_map<ModuleName, size_t> moduleNameToQueue;
+
+    for (size_t i = 0; i < buildQueueItems.size(); i++)
+    {
+        BuildQueueItem& item = buildQueueItems[i];
+        moduleNameToQueue[item.name] = i;
+    }
+
+    // Default task execution is single-threaded and immediate
+    if (!executeTask)
+    {
+        executeTask = [](std::function<void()> task)
+        {
+            task();
+        };
+    }
+
+    std::mutex mtx;
+    std::condition_variable cv;
+    std::vector<size_t> readyQueueItems;
+
+    size_t processing = 0;
+    size_t remaining = buildQueueItems.size();
+
+    auto itemTask = [&](size_t i)
+    {
+        BuildQueueItem& item = buildQueueItems[i];
+
+        try
+        {
+            checkBuildQueueItem(item);
+        }
+        catch (...)
+        {
+            item.exception = std::current_exception();
+        }
+
+        {
+            std::unique_lock guard(mtx);
+            readyQueueItems.push_back(i);
+        }
+
+        cv.notify_one();
+    };
+
+    auto sendItemTask = [&](size_t i)
+    {
+        BuildQueueItem& item = buildQueueItems[i];
+
+        item.processing = true;
+        processing++;
+
+        executeTask(
+            [&itemTask, i]()
+            {
+                itemTask(i);
+            }
+        );
+    };
+
+    auto sendCycleItemTask = [&]
+    {
+        for (size_t i = 0; i < buildQueueItems.size(); i++)
+        {
+            BuildQueueItem& item = buildQueueItems[i];
+
+            if (!item.processing)
+            {
+                sendItemTask(i);
+                break;
+            }
+        }
+    };
+
+    // In a first pass, check modules that have no dependencies and record info of those modules that wait
+    for (size_t i = 0; i < buildQueueItems.size(); i++)
+    {
+        BuildQueueItem& item = buildQueueItems[i];
+
+        for (const ModuleName& dep : item.sourceNode->requireSet)
+        {
+            if (auto it = sourceNodes.find(dep); it != sourceNodes.end())
+            {
+                if (it->second->hasDirtyModule(frontendOptions.forAutocomplete))
+                {
+                    item.dirtyDependencies++;
+
+                    buildQueueItems[moduleNameToQueue[dep]].reverseDeps.push_back(i);
+                }
+            }
+        }
+
+        if (item.dirtyDependencies == 0)
+            sendItemTask(i);
+    }
+
+    // Not a single item was found, a cycle in the graph was hit
+    if (processing == 0)
+        sendCycleItemTask();
+
+    std::vector<size_t> nextItems;
+    std::optional<size_t> itemWithException;
+    bool cancelled = false;
+
+    while (remaining != 0)
+    {
+        {
+            std::unique_lock guard(mtx);
+
+            // If nothing is ready yet, wait
+            cv.wait(
+                guard,
+                [&readyQueueItems]
+                {
+                    return !readyQueueItems.empty();
+                }
+            );
+
+            // Handle checked items
+            for (size_t i : readyQueueItems)
+            {
+                const BuildQueueItem& item = buildQueueItems[i];
+
+                // If exception was thrown, stop adding new items and wait for processing items to complete
+                if (item.exception)
+                    itemWithException = i;
+
+                if (item.module && item.module->cancelled)
+                    cancelled = true;
+
+                if (itemWithException || cancelled)
+                    break;
+
+                recordItemResult(item);
+
+                // Notify items that were waiting for this dependency
+                for (size_t reverseDep : item.reverseDeps)
+                {
+                    BuildQueueItem& reverseDepItem = buildQueueItems[reverseDep];
+
+                    LUAU_ASSERT(reverseDepItem.dirtyDependencies != 0);
+                    reverseDepItem.dirtyDependencies--;
+
+                    // In case of a module cycle earlier, check if unlocked an item that was already processed
+                    if (!reverseDepItem.processing && reverseDepItem.dirtyDependencies == 0)
+                        nextItems.push_back(reverseDep);
+                }
+            }
+
+            LUAU_ASSERT(processing >= readyQueueItems.size());
+            processing -= readyQueueItems.size();
+
+            LUAU_ASSERT(remaining >= readyQueueItems.size());
+            remaining -= readyQueueItems.size();
+            readyQueueItems.clear();
+        }
+
+        if (progress)
+        {
+            if (!progress(buildQueueItems.size() - remaining, buildQueueItems.size()))
+                cancelled = true;
+        }
+
+        // Items cannot be submitted while holding the lock
+        for (size_t i : nextItems)
+            sendItemTask(i);
+        nextItems.clear();
+
+        if (processing == 0)
+        {
+            // Typechecking might have been cancelled by user, don't return partial results
+            if (cancelled)
+                return {};
+
+            // We might have stopped because of a pending exception
+            if (itemWithException)
+                recordItemResult(buildQueueItems[*itemWithException]);
+        }
+
+        // If we aren't done, but don't have anything processing, we hit a cycle
+        if (remaining != 0 && processing == 0)
+            sendCycleItemTask();
+    }
+
+    std::vector<ModuleName> checkedModules;
+    checkedModules.reserve(buildQueueItems.size());
+
+    for (size_t i = 0; i < buildQueueItems.size(); i++)
+        checkedModules.push_back(std::move(buildQueueItems[i].name));
+
+    return checkedModules;
+}
+
 std::optional<CheckResult> Frontend::getCheckResult(const ModuleName& name, bool accumulateNested, bool forAutocomplete)
 {
     if (FFlag::LuauSolverV2)
@@ -1102,27 +1367,13 @@ void Frontend::performQueueItemTask(std::shared_ptr<BuildQueueWorkState> state,
 {
     BuildQueueItem& item = state->buildQueueItems[itemPos];
 
-    if (DFFlag::LuauRethrowKnownExceptions)
+    try
     {
-        try
-        {
-            checkBuildQueueItem(item);
-        }
-        catch (const Luau::InternalCompilerError&)
-        {
-            item.exception = std::current_exception();
-        }
+        checkBuildQueueItem(item);
     }
-    else
+    catch (...)
     {
-        try
-        {
-            checkBuildQueueItem(item);
-        }
-        catch (...)
-        {
-            item.exception = std::current_exception();
-        }
+        item.exception = std::current_exception();
     }
 
     {
@@ -1281,7 +1532,6 @@ ModulePtr check(
     NotNull<ModuleResolver> moduleResolver,
     NotNull<FileResolver> fileResolver,
     const ScopePtr& parentScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     FrontendOptions options,
     TypeCheckLimits limits,
@@ -1298,7 +1548,6 @@ ModulePtr check(
         moduleResolver,
         fileResolver,
         parentScope,
-        typeFunctionScope,
         std::move(prepareModuleScope),
         options,
         limits,
@@ -1360,7 +1609,6 @@ ModulePtr check(
     NotNull<ModuleResolver> moduleResolver,
     NotNull<FileResolver> fileResolver,
     const ScopePtr& parentScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     FrontendOptions options,
     TypeCheckLimits limits,
@@ -1381,7 +1629,8 @@ ModulePtr check(
     result->interfaceTypes.owningModule = result.get();
     result->allocator = sourceModule.allocator;
     result->names = sourceModule.names;
-    result->root = sourceModule.root;
+    if (FFlag::LuauModuleHoldsAstRoot)
+        result->root = sourceModule.root;
 
     iceHandler->moduleName = sourceModule.name;
 
@@ -1406,7 +1655,7 @@ ModulePtr check(
     SimplifierPtr simplifier = newSimplifier(NotNull{&result->internalTypes}, builtinTypes);
     TypeFunctionRuntime typeFunctionRuntime{iceHandler, NotNull{&limits}};
 
-    typeFunctionRuntime.allowEvaluation = FFlag::LuauTypeFunResultInAutocomplete || sourceModule.parseErrors.empty();
+    typeFunctionRuntime.allowEvaluation = sourceModule.parseErrors.empty();
 
     ConstraintGenerator cg{
         result,
@@ -1417,7 +1666,6 @@ ModulePtr check(
         builtinTypes,
         iceHandler,
         parentScope,
-        typeFunctionScope,
         std::move(prepareModuleScope),
         logger.get(),
         NotNull{&dfg},
@@ -1600,7 +1848,6 @@ ModulePtr Frontend::check(
                 NotNull{forAutocomplete ? &moduleResolverForAutocomplete : &moduleResolver},
                 NotNull{fileResolver},
                 environmentScope ? *environmentScope : globals.globalScope,
-                globals.globalTypeFunctionScope,
                 prepareModuleScopeWrap,
                 options,
                 typeCheckLimits,

Analysis/src/Generalization.cpp

@@ -12,6 +12,7 @@
 #include "Luau/VisitType.h"
 
 LUAU_FASTFLAG(LuauAutocompleteRefactorsForIncrementalAutocomplete)
+LUAU_FASTFLAGVARIABLE(LuauGeneralizationRemoveRecursiveUpperBound2)
 
 namespace Luau
 {
@@ -29,6 +30,7 @@ struct MutatingGeneralizer : TypeOnceVisitor
     std::vector<TypePackId> genericPacks;
 
     bool isWithinFunction = false;
+    bool avoidSealingTables = false;
 
     MutatingGeneralizer(
         NotNull<TypeArena> arena,
@@ -36,7 +38,8 @@ struct MutatingGeneralizer : TypeOnceVisitor
         NotNull<Scope> scope,
         NotNull<DenseHashSet<TypeId>> cachedTypes,
         DenseHashMap<const void*, size_t> positiveTypes,
-        DenseHashMap<const void*, size_t> negativeTypes
+        DenseHashMap<const void*, size_t> negativeTypes,
+        bool avoidSealingTables
     )
         : TypeOnceVisitor(/* skipBoundTypes */ true)
         , arena(arena)
@@ -45,6 +48,7 @@ struct MutatingGeneralizer : TypeOnceVisitor
         , cachedTypes(cachedTypes)
         , positiveTypes(std::move(positiveTypes))
         , negativeTypes(std::move(negativeTypes))
+        , avoidSealingTables(avoidSealingTables)
     {
     }
 
@@ -95,7 +99,7 @@ struct MutatingGeneralizer : TypeOnceVisitor
                 LUAU_ASSERT(onlyType != haystack);
                 emplaceType<BoundType>(asMutable(haystack), onlyType);
             }
-            else if (ut->options.empty())
+            else if (FFlag::LuauGeneralizationRemoveRecursiveUpperBound2 && ut->options.empty())
             {
                 emplaceType<BoundType>(asMutable(haystack), builtinTypes->neverType);
             }
@@ -142,7 +146,7 @@ struct MutatingGeneralizer : TypeOnceVisitor
                 LUAU_ASSERT(onlyType != needle);
                 emplaceType<BoundType>(asMutable(needle), onlyType);
             } 
-            else if (it->parts.empty())
+            else if (FFlag::LuauGeneralizationRemoveRecursiveUpperBound2 && it->parts.empty())
             {
                 emplaceType<BoundType>(asMutable(needle), builtinTypes->unknownType);
             }
@@ -288,7 +292,8 @@ struct MutatingGeneralizer : TypeOnceVisitor
         TableType* tt = getMutable<TableType>(ty);
         LUAU_ASSERT(tt);
 
-        tt->state = TableState::Sealed;
+        if (!avoidSealingTables)
+            tt->state = TableState::Sealed;
 
         return true;
     }
@@ -327,19 +332,26 @@ struct FreeTypeSearcher : TypeVisitor
     {
     }
 
-    Polarity polarity = Polarity::Positive;
+    enum Polarity
+    {
+        Positive,
+        Negative,
+        Both,
+    };
+
+    Polarity polarity = Positive;
 
     void flip()
     {
         switch (polarity)
         {
-        case Polarity::Positive:
-            polarity = Polarity::Negative;
+        case Positive:
+            polarity = Negative;
             break;
-        case Polarity::Negative:
-            polarity = Polarity::Positive;
+        case Negative:
+            polarity = Positive;
             break;
-        default:
+        case Both:
             break;
         }
     }
@@ -347,11 +359,11 @@ struct FreeTypeSearcher : TypeVisitor
     DenseHashSet<const void*> seenPositive{nullptr};
     DenseHashSet<const void*> seenNegative{nullptr};
 
-    bool seenWithCurrentPolarity(const void* ty)
+    bool seenWithPolarity(const void* ty)
     {
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
         {
             if (seenPositive.contains(ty))
                 return true;
@@ -359,7 +371,7 @@ struct FreeTypeSearcher : TypeVisitor
             seenPositive.insert(ty);
             return false;
         }
-        case Polarity::Negative:
+        case Negative:
         {
             if (seenNegative.contains(ty))
                 return true;
@@ -367,7 +379,7 @@ struct FreeTypeSearcher : TypeVisitor
             seenNegative.insert(ty);
             return false;
         }
-        case Polarity::Mixed:
+        case Both:
         {
             if (seenPositive.contains(ty) && seenNegative.contains(ty))
                 return true;
@@ -376,8 +388,6 @@ struct FreeTypeSearcher : TypeVisitor
             seenNegative.insert(ty);
             return false;
         }
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return false;
@@ -391,7 +401,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty) override
     {
-        if (cachedTypes->contains(ty) || seenWithCurrentPolarity(ty))
+        if (cachedTypes->contains(ty) || seenWithPolarity(ty))
             return false;
 
         LUAU_ASSERT(ty);
@@ -400,7 +410,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const FreeType& ft) override
     {
-        if (cachedTypes->contains(ty) || seenWithCurrentPolarity(ty))
+        if (cachedTypes->contains(ty) || seenWithPolarity(ty))
             return false;
 
         if (!subsumes(scope, ft.scope))
@@ -408,18 +418,16 @@ struct FreeTypeSearcher : TypeVisitor
 
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
             positiveTypes[ty]++;
             break;
-        case Polarity::Negative:
+        case Negative:
             negativeTypes[ty]++;
             break;
-        case Polarity::Mixed:
+        case Both:
             positiveTypes[ty]++;
             negativeTypes[ty]++;
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return true;
@@ -427,25 +435,23 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const TableType& tt) override
     {
-        if (cachedTypes->contains(ty) || seenWithCurrentPolarity(ty))
+        if (cachedTypes->contains(ty) || seenWithPolarity(ty))
             return false;
 
         if ((tt.state == TableState::Free || tt.state == TableState::Unsealed) && subsumes(scope, tt.scope))
         {
             switch (polarity)
             {
-            case Polarity::Positive:
+            case Positive:
                 positiveTypes[ty]++;
                 break;
-            case Polarity::Negative:
+            case Negative:
                 negativeTypes[ty]++;
                 break;
-            case Polarity::Mixed:
+            case Both:
                 positiveTypes[ty]++;
                 negativeTypes[ty]++;
                 break;
-            default:
-                LUAU_ASSERT(!"Unreachable");
             }
         }
 
@@ -458,7 +464,7 @@ struct FreeTypeSearcher : TypeVisitor
                 LUAU_ASSERT(prop.isShared() || FFlag::LuauAutocompleteRefactorsForIncrementalAutocomplete);
 
                 Polarity p = polarity;
-                polarity = Polarity::Mixed;
+                polarity = Both;
                 traverse(prop.type());
                 polarity = p;
             }
@@ -475,7 +481,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const FunctionType& ft) override
     {
-        if (cachedTypes->contains(ty) || seenWithCurrentPolarity(ty))
+        if (cachedTypes->contains(ty) || seenWithPolarity(ty))
             return false;
 
         flip();
@@ -494,7 +500,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypePackId tp, const FreeTypePack& ftp) override
     {
-        if (seenWithCurrentPolarity(tp))
+        if (seenWithPolarity(tp))
             return false;
 
         if (!subsumes(scope, ftp.scope))
@@ -502,18 +508,16 @@ struct FreeTypeSearcher : TypeVisitor
 
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
             positiveTypes[tp]++;
             break;
-        case Polarity::Negative:
+        case Negative:
             negativeTypes[tp]++;
             break;
-        case Polarity::Mixed:
+        case Both:
             positiveTypes[tp]++;
             negativeTypes[tp]++;
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return true;
@@ -543,7 +547,7 @@ struct TypeCacher : TypeOnceVisitor
     {
     }
 
-    void cache(TypeId ty) const
+    void cache(TypeId ty)
     {
         cachedTypes->insert(ty);
     }
@@ -968,7 +972,8 @@ std::optional<TypeId> generalize(
     NotNull<BuiltinTypes> builtinTypes,
     NotNull<Scope> scope,
     NotNull<DenseHashSet<TypeId>> cachedTypes,
-    TypeId ty
+    TypeId ty,
+    bool avoidSealingTables
 )
 {
     ty = follow(ty);
@@ -979,7 +984,7 @@ std::optional<TypeId> generalize(
     FreeTypeSearcher fts{scope, cachedTypes};
     fts.traverse(ty);
 
-    MutatingGeneralizer gen{arena, builtinTypes, scope, cachedTypes, std::move(fts.positiveTypes), std::move(fts.negativeTypes)};
+    MutatingGeneralizer gen{arena, builtinTypes, scope, cachedTypes, std::move(fts.positiveTypes), std::move(fts.negativeTypes), avoidSealingTables};
 
     gen.traverse(ty);
 

Analysis/src/GlobalTypes.cpp

@@ -9,7 +9,6 @@ GlobalTypes::GlobalTypes(NotNull<BuiltinTypes> builtinTypes)
     : builtinTypes(builtinTypes)
 {
     globalScope = std::make_shared<Scope>(globalTypes.addTypePack(TypePackVar{FreeTypePack{TypeLevel{}}}));
-    globalTypeFunctionScope = std::make_shared<Scope>(globalTypes.addTypePack(TypePackVar{FreeTypePack{TypeLevel{}}}));
 
     globalScope->addBuiltinTypeBinding("any", TypeFun{{}, builtinTypes->anyType});
     globalScope->addBuiltinTypeBinding("nil", TypeFun{{}, builtinTypes->nilType});

Analysis/src/Instantiation.cpp

@@ -61,7 +61,7 @@ TypeId Instantiation::clean(TypeId ty)
     const FunctionType* ftv = log->getMutable<FunctionType>(ty);
     LUAU_ASSERT(ftv);
 
-    FunctionType clone = FunctionType{level, ftv->argTypes, ftv->retTypes, ftv->definition, ftv->hasSelf};
+    FunctionType clone = FunctionType{level, scope, ftv->argTypes, ftv->retTypes, ftv->definition, ftv->hasSelf};
     clone.magic = ftv->magic;
     clone.tags = ftv->tags;
     clone.argNames = ftv->argNames;

Analysis/src/Linter.cpp

@@ -19,8 +19,6 @@ LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTFLAG(LuauAttribute)
 LUAU_FASTFLAGVARIABLE(LintRedundantNativeAttribute)
 
-LUAU_FASTFLAG(LuauDeprecatedAttribute)
-
 namespace Luau
 {
 
@@ -2282,57 +2280,6 @@ private:
     {
     }
 
-    bool visit(AstExprLocal* node) override
-    {
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-
-            const FunctionType* fty = getFunctionType(node);
-            bool shouldReport = fty && fty->isDeprecatedFunction && !inScope(fty);
-
-            if (shouldReport)
-                report(node->location, node->local->name.value);
-        }
-
-        return true;
-    }
-
-    bool visit(AstExprGlobal* node) override
-    {
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-            const FunctionType* fty = getFunctionType(node);
-            bool shouldReport = fty && fty->isDeprecatedFunction && !inScope(fty);
-
-            if (shouldReport)
-                report(node->location, node->name.value);
-        }
-
-        return true;
-    }
-
-    bool visit(AstStatLocalFunction* node) override
-    {
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-            check(node->func);
-            return false;
-        }
-        else
-            return true;
-    }
-
-    bool visit(AstStatFunction* node) override
-    {
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-            check(node->func);
-            return false;
-        }
-        else
-            return true;
-    }
-
     bool visit(AstExprIndexName* node) override
     {
         if (std::optional<TypeId> ty = context->getType(node->expr))
@@ -2378,59 +2325,18 @@ private:
 
             if (prop && prop->deprecated)
                 report(node->location, *prop, cty->name.c_str(), node->index.value);
-            else if (FFlag::LuauDeprecatedAttribute && prop)
-            {
-                if (std::optional<TypeId> ty = prop->readTy)
-                {
-                    const FunctionType* fty = get<FunctionType>(follow(ty));
-                    bool shouldReport = fty && fty->isDeprecatedFunction && !inScope(fty);
-
-                    if (shouldReport)
-                    {
-                        const char* className = nullptr;
-                        if (AstExprGlobal* global = node->expr->as<AstExprGlobal>())
-                            className = global->name.value;
-
-                        const char* functionName = node->index.value;
-
-                        report(node->location, className, functionName);
-                    }
-                }
-            }
         }
         else if (const TableType* tty = get<TableType>(ty))
         {
             auto prop = tty->props.find(node->index.value);
 
-            if (prop != tty->props.end())
+            if (prop != tty->props.end() && prop->second.deprecated)
             {
-                if (prop->second.deprecated)
-                {
-                    // strip synthetic typeof() for builtin tables
-                    if (tty->name && tty->name->compare(0, 7, "typeof(") == 0 && tty->name->back() == ')')
-                        report(node->location, prop->second, tty->name->substr(7, tty->name->length() - 8).c_str(), node->index.value);
-                    else
-                        report(node->location, prop->second, tty->name ? tty->name->c_str() : nullptr, node->index.value);
-                }
-                else if (FFlag::LuauDeprecatedAttribute)
-                {
-                    if (std::optional<TypeId> ty = prop->second.readTy)
-                    {
-                        const FunctionType* fty = get<FunctionType>(follow(ty));
-                        bool shouldReport = fty && fty->isDeprecatedFunction && !inScope(fty);
-
-                        if (shouldReport)
-                        {
-                            const char* className = nullptr;
-                            if (AstExprGlobal* global = node->expr->as<AstExprGlobal>())
-                                className = global->name.value;
-
-                            const char* functionName = node->index.value;
-
-                            report(node->location, className, functionName);
-                        }
-                    }
-                }
+                // strip synthetic typeof() for builtin tables
+                if (tty->name && tty->name->compare(0, 7, "typeof(") == 0 && tty->name->back() == ')')
+                    report(node->location, prop->second, tty->name->substr(7, tty->name->length() - 8).c_str(), node->index.value);
+                else
+                    report(node->location, prop->second, tty->name ? tty->name->c_str() : nullptr, node->index.value);
             }
         }
     }
@@ -2449,26 +2355,6 @@ private:
         }
     }
 
-    void check(AstExprFunction* func)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-        LUAU_ASSERT(func);
-
-        const FunctionType* fty = getFunctionType(func);
-        bool isDeprecated = fty && fty->isDeprecatedFunction;
-
-        // If a function is deprecated, we don't want to flag its recursive uses.
-        // So we push it on a stack while its body is being analyzed.
-        // When a deprecated function is used, we check the stack to ensure that we are not inside that function.
-        if (isDeprecated)
-            pushScope(fty);
-
-        func->visit(this);
-
-        if (isDeprecated)
-            popScope(fty);
-    }
-
     void report(const Location& location, const Property& prop, const char* container, const char* field)
     {
         std::string suggestion = prop.deprecatedSuggestion.empty() ? "" : format(", use '%s' instead", prop.deprecatedSuggestion.c_str());
@@ -2478,63 +2364,6 @@ private:
         else
             emitWarning(*context, LintWarning::Code_DeprecatedApi, location, "Member '%s' is deprecated%s", field, suggestion.c_str());
     }
-
-    void report(const Location& location, const char* tableName, const char* functionName)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-        if (tableName)
-            emitWarning(*context, LintWarning::Code_DeprecatedApi, location, "Member '%s.%s' is deprecated", tableName, functionName);
-        else
-            emitWarning(*context, LintWarning::Code_DeprecatedApi, location, "Member '%s' is deprecated", functionName);
-    }
-
-    void report(const Location& location, const char* functionName)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-        emitWarning(*context, LintWarning::Code_DeprecatedApi, location, "Function '%s' is deprecated", functionName);
-    }
-
-    std::vector<const FunctionType*> functionTypeScopeStack;
-
-    void pushScope(const FunctionType* fty)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-        LUAU_ASSERT(fty);
-
-        functionTypeScopeStack.push_back(fty);
-    }
-
-    void popScope(const FunctionType* fty)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-        LUAU_ASSERT(fty);
-
-        LUAU_ASSERT(fty == functionTypeScopeStack.back());
-        functionTypeScopeStack.pop_back();
-    }
-
-    bool inScope(const FunctionType* fty) const
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-        LUAU_ASSERT(fty);
-
-        return std::find(functionTypeScopeStack.begin(), functionTypeScopeStack.end(), fty) != functionTypeScopeStack.end();
-    }
-
-    const FunctionType* getFunctionType(AstExpr* node)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-        std::optional<TypeId> ty = context->getType(node);
-        if (!ty)
-            return nullptr;
-
-        const FunctionType* fty = get<FunctionType>(follow(ty));
-
-        return fty;
-    }
 };
 
 class LintTableOperations : AstVisitor

Analysis/src/Module.cpp

@@ -15,12 +15,12 @@
 #include <algorithm>
 
 LUAU_FASTFLAG(LuauSolverV2);
-LUAU_FASTFLAG(LuauRetainDefinitionAliasLocations)
+LUAU_FASTFLAGVARIABLE(LuauIncrementalAutocompleteCommentDetection)
 
 namespace Luau
 {
 
-static void defaultLogLuau(std::string_view context, std::string_view input)
+static void defaultLogLuau(std::string_view input)
 {
     // The default is to do nothing because we don't want to mess with
     // the xml parsing done by the dcr script.
@@ -38,6 +38,21 @@ void resetLogLuauProc()
     logLuau = &defaultLogLuau;
 }
 
+
+
+static bool contains_DEPRECATED(Position pos, Comment comment)
+{
+    if (comment.location.contains(pos))
+        return true;
+    else if (comment.type == Lexeme::BrokenComment && comment.location.begin <= pos) // Broken comments are broken specifically because they don't
+                                                                                     // have an end
+        return true;
+    else if (comment.type == Lexeme::Comment && comment.location.end == pos)
+        return true;
+    else
+        return false;
+}
+
 static bool contains(Position pos, Comment comment)
 {
     if (comment.location.contains(pos))
@@ -61,8 +76,11 @@ bool isWithinComment(const std::vector<Comment>& commentLocations, Position pos)
         Comment{Lexeme::Comment, Location{pos, pos}},
         [](const Comment& a, const Comment& b)
         {
-            if (a.type == Lexeme::Comment)
-                return a.location.end.line < b.location.end.line;
+            if (FFlag::LuauIncrementalAutocompleteCommentDetection)
+            {
+                if (a.type == Lexeme::Comment)
+                    return a.location.end.line < b.location.end.line;
+            }
             return a.location.end < b.location.end;
         }
     );
@@ -70,7 +88,7 @@ bool isWithinComment(const std::vector<Comment>& commentLocations, Position pos)
     if (iter == commentLocations.end())
         return false;
 
-    if (contains(pos, *iter))
+    if (FFlag::LuauIncrementalAutocompleteCommentDetection ? contains(pos, *iter) : contains_DEPRECATED(pos, *iter))
         return true;
 
     // Due to the nature of std::lower_bound, it is possible that iter points at a comment that ends
@@ -154,6 +172,8 @@ struct ClonePublicInterface : Substitution
             }
 
             ftv->level = TypeLevel{0, 0};
+            if (FFlag::LuauSolverV2)
+                ftv->scope = nullptr;
         }
         else if (TableType* ttv = getMutable<TableType>(result))
         {
@@ -265,10 +285,7 @@ struct ClonePublicInterface : Substitution
 
         TypeId type = cloneType(tf.type);
 
-        if (FFlag::LuauRetainDefinitionAliasLocations)
-            return TypeFun{typeParams, typePackParams, type, tf.definitionLocation};
-        else
-            return TypeFun{typeParams, typePackParams, type};
+        return TypeFun{typeParams, typePackParams, type};
     }
 };
 

Analysis/src/NonStrictTypeChecker.cpp

@@ -2,7 +2,6 @@
 #include "Luau/NonStrictTypeChecker.h"
 
 #include "Luau/Ast.h"
-#include "Luau/AstQuery.h"
 #include "Luau/Common.h"
 #include "Luau/Simplify.h"
 #include "Luau/Type.h"
@@ -23,7 +22,6 @@
 LUAU_FASTFLAG(LuauFreeTypesMustHaveBounds)
 LUAU_FASTFLAGVARIABLE(LuauNonStrictVisitorImprovements)
 LUAU_FASTFLAGVARIABLE(LuauNewNonStrictWarnOnUnknownGlobals)
-LUAU_FASTFLAGVARIABLE(LuauNonStrictFuncDefErrorFix)
 
 namespace Luau
 {
@@ -765,17 +763,7 @@ struct NonStrictTypeChecker
         for (AstLocal* local : exprFn->args)
         {
             if (std::optional<TypeId> ty = willRunTimeErrorFunctionDefinition(local, remainder))
-            {
-                if (FFlag::LuauNonStrictFuncDefErrorFix)
-                {
-                    const char* debugname = exprFn->debugname.value;
-                    reportError(NonStrictFunctionDefinitionError{debugname ? debugname : "", local->name.value, *ty}, local->location);
-                }
-                else
-                {
-                    reportError(NonStrictFunctionDefinitionError{exprFn->debugname.value, local->name.value, *ty}, local->location);
-                }
-            }
+                reportError(NonStrictFunctionDefinitionError{exprFn->debugname.value, local->name.value, *ty}, local->location);
             remainder.remove(dfg->getDef(local));
         }
         return remainder;

Analysis/src/Normalize.cpp

@@ -17,16 +17,12 @@
 
 LUAU_FASTFLAGVARIABLE(DebugLuauCheckNormalizeInvariant)
 
-LUAU_FASTFLAGVARIABLE(LuauNormalizeNegatedErrorToAnError)
-LUAU_FASTFLAGVARIABLE(LuauNormalizeIntersectErrorToAnError)
 LUAU_FASTINTVARIABLE(LuauNormalizeCacheLimit, 100000)
 LUAU_FASTINTVARIABLE(LuauNormalizeIntersectionLimit, 200)
-LUAU_FASTINTVARIABLE(LuauNormalizeUnionLimit, 100)
 LUAU_FASTFLAG(LuauSolverV2)
+LUAU_FASTFLAGVARIABLE(LuauNormalizeNegationFix)
 LUAU_FASTFLAGVARIABLE(LuauFixInfiniteRecursionInNormalization)
-LUAU_FASTFLAGVARIABLE(LuauNormalizedBufferIsNotUnknown)
-LUAU_FASTFLAGVARIABLE(LuauNormalizeLimitFunctionSet)
-LUAU_FASTFLAGVARIABLE(LuauNormalizationCatchMetatableCycles)
+LUAU_FASTFLAGVARIABLE(LuauFixNormalizedIntersectionOfNegatedClass)
 
 namespace Luau
 {
@@ -308,9 +304,7 @@ bool NormalizedType::isUnknown() const
 
     // Otherwise, we can still be unknown!
     bool hasAllPrimitives = isPrim(booleans, PrimitiveType::Boolean) && isPrim(nils, PrimitiveType::NilType) && isNumber(numbers) &&
-                            strings.isString() &&
-                            (FFlag::LuauNormalizedBufferIsNotUnknown ? isThread(threads) && isBuffer(buffers)
-                                                                     : isPrim(threads, PrimitiveType::Thread) && isThread(threads));
+                            strings.isString() && isPrim(threads, PrimitiveType::Thread) && isThread(threads);
 
     // Check is class
     bool isTopClass = false;
@@ -585,7 +579,7 @@ NormalizationResult Normalizer::isIntersectionInhabited(TypeId left, TypeId righ
 {
     left = follow(left);
     right = follow(right);
-    // We're asking if intersection is inhabited between left and right but we've already seen them ....
+    // We're asking if intersection is inahbited between left and right but we've already seen them ....
 
     if (cacheInhabitance)
     {
@@ -1691,13 +1685,6 @@ NormalizationResult Normalizer::unionNormals(NormalizedType& here, const Normali
             return res;
     }
 
-    if (FFlag::LuauNormalizeLimitFunctionSet)
-    {
-        // Limit based on worst-case expansion of the function unions
-        if (here.functions.parts.size() * there.functions.parts.size() >= size_t(FInt::LuauNormalizeUnionLimit))
-            return NormalizationResult::HitLimits;
-    }
-
     here.booleans = unionOfBools(here.booleans, there.booleans);
     unionClasses(here.classes, there.classes);
 
@@ -1709,7 +1696,6 @@ NormalizationResult Normalizer::unionNormals(NormalizedType& here, const Normali
     here.buffers = (get<NeverType>(there.buffers) ? here.buffers : there.buffers);
     unionFunctions(here.functions, there.functions);
     unionTables(here.tables, there.tables);
-
     return NormalizationResult::True;
 }
 
@@ -1749,7 +1735,7 @@ NormalizationResult Normalizer::intersectNormalWithNegationTy(TypeId toNegate, N
     return NormalizationResult::True;
 }
 
-// See above for an explanation of `ignoreSmallerTyvars`.
+// See above for an explaination of `ignoreSmallerTyvars`.
 NormalizationResult Normalizer::unionNormalWithTy(
     NormalizedType& here,
     TypeId there,
@@ -2303,7 +2289,7 @@ void Normalizer::intersectClassesWithClass(NormalizedClassType& heres, TypeId th
 
             for (auto nIt = negations.begin(); nIt != negations.end();)
             {
-                if (isSubclass(there, *nIt))
+                if (FFlag::LuauFixNormalizedIntersectionOfNegatedClass && isSubclass(there, *nIt))
                 {
                     // Hitting this block means that the incoming class is a
                     // subclass of this type, _and_ one of its negations is a
@@ -3064,7 +3050,7 @@ NormalizationResult Normalizer::intersectTyvarsWithTy(
     return NormalizationResult::True;
 }
 
-// See above for an explanation of `ignoreSmallerTyvars`.
+// See above for an explaination of `ignoreSmallerTyvars`.
 NormalizationResult Normalizer::intersectNormals(NormalizedType& here, const NormalizedType& there, int ignoreSmallerTyvars)
 {
     RecursionCounter _rc(&sharedState->counters.recursionCount);
@@ -3082,17 +3068,11 @@ NormalizationResult Normalizer::intersectNormals(NormalizedType& here, const Nor
         return unionNormals(here, there, ignoreSmallerTyvars);
     }
 
-    // Limit based on worst-case expansion of the table/function intersections
+    // Limit based on worst-case expansion of the table intersection
     // This restriction can be relaxed when table intersection simplification is improved
     if (here.tables.size() * there.tables.size() >= size_t(FInt::LuauNormalizeIntersectionLimit))
         return NormalizationResult::HitLimits;
 
-    if (FFlag::LuauNormalizeLimitFunctionSet)
-    {
-        if (here.functions.parts.size() * there.functions.parts.size() >= size_t(FInt::LuauNormalizeIntersectionLimit))
-            return NormalizationResult::HitLimits;
-    }
-
     here.booleans = intersectionOfBools(here.booleans, there.booleans);
 
     intersectClasses(here.classes, there.classes);
@@ -3228,7 +3208,7 @@ NormalizationResult Normalizer::intersectNormalWithTy(
     {
         TypeId errors = here.errors;
         clearNormal(here);
-        here.errors = FFlag::LuauNormalizeIntersectErrorToAnError && get<ErrorType>(errors) ? errors : there;
+        here.errors = errors;
     }
     else if (const PrimitiveType* ptv = get<PrimitiveType>(there))
     {
@@ -3325,16 +3305,11 @@ NormalizationResult Normalizer::intersectNormalWithTy(
             clearNormal(here);
             return NormalizationResult::True;
         }
-        else if (FFlag::LuauNormalizeNegatedErrorToAnError && get<ErrorType>(t))
-        {
-            // ~error is still an error, so intersecting with the negation is the same as intersecting with a type
-            TypeId errors = here.errors;
-            clearNormal(here);
-            here.errors = FFlag::LuauNormalizeIntersectErrorToAnError && get<ErrorType>(errors) ? errors : t;
-        }
         else if (auto nt = get<NegationType>(t))
         {
-            here.tyvars = std::move(tyvars);
+            if (FFlag::LuauNormalizeNegationFix)
+                here.tyvars = std::move(tyvars);
+
             return intersectNormalWithTy(here, nt->ty, seenTablePropPairs, seenSetTypes);
         }
         else
@@ -3364,43 +3339,19 @@ NormalizationResult Normalizer::intersectNormalWithTy(
     return NormalizationResult::True;
 }
 
-void makeTableShared_DEPRECATED(TypeId ty)
-{
-    ty = follow(ty);
-    if (auto tableTy = getMutable<TableType>(ty))
-    {
-        for (auto& [_, prop] : tableTy->props)
-            prop.makeShared();
-    }
-    else if (auto metatableTy = get<MetatableType>(ty))
-    {
-        makeTableShared_DEPRECATED(metatableTy->metatable);
-        makeTableShared_DEPRECATED(metatableTy->table);
-    }
-}
-
-void makeTableShared(TypeId ty, DenseHashSet<TypeId>& seen)
-{
-    ty = follow(ty);
-    if (seen.contains(ty))
-        return;
-    seen.insert(ty);
-    if (auto tableTy = getMutable<TableType>(ty))
-    {
-        for (auto& [_, prop] : tableTy->props)
-            prop.makeShared();
-    }
-    else if (auto metatableTy = get<MetatableType>(ty))
-    {
-        makeTableShared(metatableTy->metatable, seen);
-        makeTableShared(metatableTy->table, seen);
-    }
-}
-
 void makeTableShared(TypeId ty)
 {
-    DenseHashSet<TypeId> seen{nullptr};
-    makeTableShared(ty, seen);
+    ty = follow(ty);
+    if (auto tableTy = getMutable<TableType>(ty))
+    {
+        for (auto& [_, prop] : tableTy->props)
+            prop.makeShared();
+    }
+    else if (auto metatableTy = get<MetatableType>(ty))
+    {
+        makeTableShared(metatableTy->metatable);
+        makeTableShared(metatableTy->table);
+    }
 }
 
 // -------- Convert back from a normalized type to a type
@@ -3502,10 +3453,7 @@ TypeId Normalizer::typeFromNormal(const NormalizedType& norm)
         result.reserve(result.size() + norm.tables.size());
         for (auto table : norm.tables)
         {
-            if (FFlag::LuauNormalizationCatchMetatableCycles)
-                makeTableShared(table);
-            else
-                makeTableShared_DEPRECATED(table);
+            makeTableShared(table);
             result.push_back(table);
         }
     }

Analysis/src/OverloadResolution.cpp

@@ -454,7 +454,7 @@ SolveResult solveFunctionCall(
 
     TypePackId resultPack = arena->freshTypePack(scope);
 
-    TypeId inferredTy = arena->addType(FunctionType{TypeLevel{}, argsPack, resultPack});
+    TypeId inferredTy = arena->addType(FunctionType{TypeLevel{}, scope.get(), argsPack, resultPack});
     Unifier2 u2{NotNull{arena}, builtinTypes, scope, iceReporter};
 
     const bool occursCheckPassed = u2.unify(*overloadToUse, inferredTy);

Analysis/src/RequireTracer.cpp

@@ -4,6 +4,8 @@
 #include "Luau/Ast.h"
 #include "Luau/Module.h"
 
+LUAU_FASTFLAGVARIABLE(LuauExtendedSimpleRequire)
+
 namespace Luau
 {
 
@@ -104,50 +106,96 @@ struct RequireTracer : AstVisitor
     {
         ModuleInfo moduleContext{currentModuleName};
 
-        // seed worklist with require arguments
-        work.reserve(requireCalls.size());
-
-        for (AstExprCall* require : requireCalls)
-            work.push_back(require->args.data[0]);
-
-        // push all dependent expressions to the work stack; note that the vector is modified during traversal
-        for (size_t i = 0; i < work.size(); ++i)
+        if (FFlag::LuauExtendedSimpleRequire)
         {
-            if (AstNode* dep = getDependent(work[i]))
-                work.push_back(dep);
-        }
+            // seed worklist with require arguments
+            work.reserve(requireCalls.size());
 
-        // resolve all expressions to a module info
-        for (size_t i = work.size(); i > 0; --i)
-        {
-            AstNode* expr = work[i - 1];
+            for (AstExprCall* require : requireCalls)
+                work.push_back(require->args.data[0]);
 
-            // when multiple expressions depend on the same one we push it to work queue multiple times
-            if (result.exprs.contains(expr))
-                continue;
-
-            std::optional<ModuleInfo> info;
-
-            if (AstNode* dep = getDependent(expr))
+            // push all dependent expressions to the work stack; note that the vector is modified during traversal
+            for (size_t i = 0; i < work.size(); ++i)
             {
-                const ModuleInfo* context = result.exprs.find(dep);
+                if (AstNode* dep = getDependent(work[i]))
+                    work.push_back(dep);
+            }
 
-                if (context && expr->is<AstExprLocal>())
-                    info = *context; // locals just inherit their dependent context, no resolution required
-                else if (context && (expr->is<AstExprGroup>() || expr->is<AstTypeGroup>()))
-                    info = *context; // simple group nodes propagate their value
-                else if (context && (expr->is<AstTypeTypeof>() || expr->is<AstExprTypeAssertion>()))
-                    info = *context; // typeof type annotations will resolve to the typeof content
+            // resolve all expressions to a module info
+            for (size_t i = work.size(); i > 0; --i)
+            {
+                AstNode* expr = work[i - 1];
+
+                // when multiple expressions depend on the same one we push it to work queue multiple times
+                if (result.exprs.contains(expr))
+                    continue;
+
+                std::optional<ModuleInfo> info;
+
+                if (AstNode* dep = getDependent(expr))
+                {
+                    const ModuleInfo* context = result.exprs.find(dep);
+
+                    if (context && expr->is<AstExprLocal>())
+                        info = *context; // locals just inherit their dependent context, no resolution required
+                    else if (context && (expr->is<AstExprGroup>() || expr->is<AstTypeGroup>()))
+                        info = *context; // simple group nodes propagate their value
+                    else if (context && (expr->is<AstTypeTypeof>() || expr->is<AstExprTypeAssertion>()))
+                        info = *context; // typeof type annotations will resolve to the typeof content
+                    else if (AstExpr* asExpr = expr->asExpr())
+                        info = fileResolver->resolveModule(context, asExpr);
+                }
                 else if (AstExpr* asExpr = expr->asExpr())
-                    info = fileResolver->resolveModule(context, asExpr);
-            }
-            else if (AstExpr* asExpr = expr->asExpr())
-            {
-                info = fileResolver->resolveModule(&moduleContext, asExpr);
-            }
+                {
+                    info = fileResolver->resolveModule(&moduleContext, asExpr);
+                }
 
-            if (info)
-                result.exprs[expr] = std::move(*info);
+                if (info)
+                    result.exprs[expr] = std::move(*info);
+            }
+        }
+        else
+        {
+            // seed worklist with require arguments
+            work_DEPRECATED.reserve(requireCalls.size());
+
+            for (AstExprCall* require : requireCalls)
+                work_DEPRECATED.push_back(require->args.data[0]);
+
+            // push all dependent expressions to the work stack; note that the vector is modified during traversal
+            for (size_t i = 0; i < work_DEPRECATED.size(); ++i)
+                if (AstExpr* dep = getDependent_DEPRECATED(work_DEPRECATED[i]))
+                    work_DEPRECATED.push_back(dep);
+
+            // resolve all expressions to a module info
+            for (size_t i = work_DEPRECATED.size(); i > 0; --i)
+            {
+                AstExpr* expr = work_DEPRECATED[i - 1];
+
+                // when multiple expressions depend on the same one we push it to work queue multiple times
+                if (result.exprs.contains(expr))
+                    continue;
+
+                std::optional<ModuleInfo> info;
+
+                if (AstExpr* dep = getDependent_DEPRECATED(expr))
+                {
+                    const ModuleInfo* context = result.exprs.find(dep);
+
+                    // locals just inherit their dependent context, no resolution required
+                    if (expr->is<AstExprLocal>())
+                        info = context ? std::optional<ModuleInfo>(*context) : std::nullopt;
+                    else
+                        info = fileResolver->resolveModule(context, expr);
+                }
+                else
+                {
+                    info = fileResolver->resolveModule(&moduleContext, expr);
+                }
+
+                if (info)
+                    result.exprs[expr] = std::move(*info);
+            }
         }
 
         // resolve all requires according to their argument
@@ -176,6 +224,7 @@ struct RequireTracer : AstVisitor
     ModuleName currentModuleName;
 
     DenseHashMap<AstLocal*, AstExpr*> locals;
+    std::vector<AstExpr*> work_DEPRECATED;
     std::vector<AstNode*> work;
     std::vector<AstExprCall*> requireCalls;
 };

Analysis/src/Scope.cpp

@@ -84,17 +84,6 @@ std::optional<TypeId> Scope::lookupUnrefinedType(DefId def) const
     return std::nullopt;
 }
 
-std::optional<TypeId> Scope::lookupRValueRefinementType(DefId def) const
-{
-    for (const Scope* current = this; current; current = current->parent.get())
-    {
-        if (auto ty = current->rvalueRefinements.find(def))
-            return *ty;
-    }
-
-    return std::nullopt;
-}
-
 std::optional<TypeId> Scope::lookup(DefId def) const
 {
     for (const Scope* current = this; current; current = current->parent.get())
@@ -192,29 +181,6 @@ std::optional<Binding> Scope::linearSearchForBinding(const std::string& name, bo
     return std::nullopt;
 }
 
-std::optional<std::pair<Symbol, Binding>> Scope::linearSearchForBindingPair(const std::string& name, bool traverseScopeChain) const
-{
-    const Scope* scope = this;
-
-    while (scope)
-    {
-        for (auto& [n, binding] : scope->bindings)
-        {
-            if (n.local && n.local->name == name.c_str())
-                return {{n, binding}};
-            else if (n.global.value && n.global == name.c_str())
-                return {{n, binding}};
-        }
-
-        scope = scope->parent.get();
-
-        if (!traverseScopeChain)
-            break;
-    }
-
-    return std::nullopt;
-}
-
 // Updates the `this` scope with the assignments from the `childScope` including ones that doesn't exist in `this`.
 void Scope::inheritAssignments(const ScopePtr& childScope)
 {

Analysis/src/Substitution.cpp

@@ -13,7 +13,6 @@ LUAU_FASTINTVARIABLE(LuauTarjanChildLimit, 10000)
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTINTVARIABLE(LuauTarjanPreallocationSize, 256)
 LUAU_FASTFLAG(LuauSyntheticErrors)
-LUAU_FASTFLAG(LuauDeprecatedAttribute)
 
 namespace Luau
 {
@@ -96,15 +95,13 @@ static TypeId shallowClone(TypeId ty, TypeArena& dest, const TxnLog* log, bool a
             return dest.addType(a);
         else if constexpr (std::is_same_v<T, FunctionType>)
         {
-            FunctionType clone = FunctionType{a.level, a.argTypes, a.retTypes, a.definition, a.hasSelf};
+            FunctionType clone = FunctionType{a.level, a.scope, a.argTypes, a.retTypes, a.definition, a.hasSelf};
             clone.generics = a.generics;
             clone.genericPacks = a.genericPacks;
             clone.magic = a.magic;
             clone.tags = a.tags;
             clone.argNames = a.argNames;
             clone.isCheckedFunction = a.isCheckedFunction;
-            if (FFlag::LuauDeprecatedAttribute)
-                clone.isDeprecatedFunction = a.isDeprecatedFunction;
             return dest.addType(std::move(clone));
         }
         else if constexpr (std::is_same_v<T, TableType>)

Analysis/src/Subtyping.cpp

@@ -22,7 +22,7 @@
 #include <algorithm>
 
 LUAU_FASTFLAGVARIABLE(DebugLuauSubtypingCheckPathValidity)
-LUAU_FASTFLAGVARIABLE(LuauSubtypingStopAtNormFail)
+LUAU_FASTFLAGVARIABLE(LuauSubtypingFixTailPack)
 
 namespace Luau
 {
@@ -416,14 +416,6 @@ SubtypingResult Subtyping::isSubtype(TypeId subTy, TypeId superTy, NotNull<Scope
 
     SubtypingResult result = isCovariantWith(env, subTy, superTy, scope);
 
-    if (FFlag::LuauSubtypingStopAtNormFail && result.normalizationTooComplex)
-    {
-        if (result.isCacheable)
-            resultCache[{subTy, superTy}] = result;
-
-        return result;
-    }
-
     for (const auto& [subTy, bounds] : env.mappedGenerics)
     {
         const auto& lb = bounds.lowerBound;
@@ -601,12 +593,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypeId sub
         if (!result.isSubtype && !result.normalizationTooComplex)
         {
             SubtypingResult semantic = isCovariantWith(env, normalizer->normalize(subTy), normalizer->normalize(superTy), scope);
-
-            if (FFlag::LuauSubtypingStopAtNormFail && semantic.normalizationTooComplex)
-            {
-                result = semantic;
-            }
-            else if (semantic.isSubtype)
+            if (semantic.isSubtype)
             {
                 semantic.reasoning.clear();
                 result = semantic;
@@ -621,12 +608,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypeId sub
         if (!result.isSubtype && !result.normalizationTooComplex)
         {
             SubtypingResult semantic = isCovariantWith(env, normalizer->normalize(subTy), normalizer->normalize(superTy), scope);
-
-            if (FFlag::LuauSubtypingStopAtNormFail && semantic.normalizationTooComplex)
-            {
-                result = semantic;
-            }
-            else if (semantic.isSubtype)
+            if (semantic.isSubtype)
             {
                 // Clear the semantic reasoning, as any reasonings within
                 // potentially contain invalid paths.
@@ -772,8 +754,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypePackId
     // Match head types pairwise
 
     for (size_t i = 0; i < headSize; ++i)
-        results.push_back(isCovariantWith(env, subHead[i], superHead[i], scope).withBothComponent(TypePath::Index{i, TypePath::Index::Variant::Pack})
-        );
+        results.push_back(isCovariantWith(env, subHead[i], superHead[i], scope).withBothComponent(TypePath::Index{i}));
 
     // Handle mismatched head sizes
 
@@ -786,7 +767,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypePackId
                 for (size_t i = headSize; i < superHead.size(); ++i)
                     results.push_back(isCovariantWith(env, vt->ty, superHead[i], scope)
                                           .withSubPath(TypePath::PathBuilder().tail().variadic().build())
-                                          .withSuperComponent(TypePath::Index{i, TypePath::Index::Variant::Pack}));
+                                          .withSuperComponent(TypePath::Index{i}));
             }
             else if (auto gt = get<GenericTypePack>(*subTail))
             {
@@ -840,7 +821,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypePackId
             {
                 for (size_t i = headSize; i < subHead.size(); ++i)
                     results.push_back(isCovariantWith(env, subHead[i], vt->ty, scope)
-                                          .withSubComponent(TypePath::Index{i, TypePath::Index::Variant::Pack})
+                                          .withSubComponent(TypePath::Index{i})
                                           .withSuperPath(TypePath::PathBuilder().tail().variadic().build()));
             }
             else if (auto gt = get<GenericTypePack>(*superTail))
@@ -878,7 +859,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypePackId
             else
                 return SubtypingResult{false}
                     .withSuperComponent(TypePath::PackField::Tail)
-                    .withError({scope->location, UnexpectedTypePackInSubtyping{*superTail}});
+                    .withError({scope->location, UnexpectedTypePackInSubtyping{FFlag::LuauSubtypingFixTailPack ? *superTail : *subTail}});
         }
         else
             return {false};
@@ -1101,10 +1082,6 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypeId sub
     for (TypeId ty : superUnion)
     {
         SubtypingResult next = isCovariantWith(env, subTy, ty, scope);
-
-        if (FFlag::LuauSubtypingStopAtNormFail && next.normalizationTooComplex)
-            return SubtypingResult{false, /* normalizationTooComplex */ true};
-
         if (next.isSubtype)
             return SubtypingResult{true};
     }
@@ -1123,13 +1100,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, const Unio
     std::vector<SubtypingResult> subtypings;
     size_t i = 0;
     for (TypeId ty : subUnion)
-    {
-        subtypings.push_back(isCovariantWith(env, ty, superTy, scope).withSubComponent(TypePath::Index{i++, TypePath::Index::Variant::Union}));
-
-        if (FFlag::LuauSubtypingStopAtNormFail && subtypings.back().normalizationTooComplex)
-            return SubtypingResult{false, /* normalizationTooComplex */ true};
-    }
-
+        subtypings.push_back(isCovariantWith(env, ty, superTy, scope).withSubComponent(TypePath::Index{i++}));
     return SubtypingResult::all(subtypings);
 }
 
@@ -1139,13 +1110,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypeId sub
     std::vector<SubtypingResult> subtypings;
     size_t i = 0;
     for (TypeId ty : superIntersection)
-    {
-        subtypings.push_back(isCovariantWith(env, subTy, ty, scope).withSuperComponent(TypePath::Index{i++, TypePath::Index::Variant::Intersection}));
-
-        if (FFlag::LuauSubtypingStopAtNormFail && subtypings.back().normalizationTooComplex)
-            return SubtypingResult{false, /* normalizationTooComplex */ true};
-    }
-
+        subtypings.push_back(isCovariantWith(env, subTy, ty, scope).withSuperComponent(TypePath::Index{i++}));
     return SubtypingResult::all(subtypings);
 }
 
@@ -1155,13 +1120,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, const Inte
     std::vector<SubtypingResult> subtypings;
     size_t i = 0;
     for (TypeId ty : subIntersection)
-    {
-        subtypings.push_back(isCovariantWith(env, ty, superTy, scope).withSubComponent(TypePath::Index{i++, TypePath::Index::Variant::Intersection}));
-
-        if (FFlag::LuauSubtypingStopAtNormFail && subtypings.back().normalizationTooComplex)
-            return SubtypingResult{false, /* normalizationTooComplex */ true};
-    }
-
+        subtypings.push_back(isCovariantWith(env, ty, superTy, scope).withSubComponent(TypePath::Index{i++}));
     return SubtypingResult::any(subtypings);
 }
 
@@ -1451,7 +1410,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, const Meta
         // of the supertype table.
         //
         // There's a flaw here in that if the __index metamethod contributes a new
-        // field that would satisfy the subtyping relationship, we'll erroneously say
+        // field that would satisfy the subtyping relationship, we'll erronously say
         // that the metatable isn't a subtype of the table, even though they have
         // compatible properties/shapes. We'll revisit this later when we have a
         // better understanding of how important this is.
@@ -1801,12 +1760,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, const Type
     {
         results.emplace_back();
         for (TypeId superTy : superTypes)
-        {
             results.back().orElse(isCovariantWith(env, subTy, superTy, scope));
-
-            if (FFlag::LuauSubtypingStopAtNormFail && results.back().normalizationTooComplex)
-                return SubtypingResult{false, /* normalizationTooComplex */ true};
-        }
     }
 
     return SubtypingResult::all(results);

Analysis/src/TableLiteralInference.cpp

@@ -13,10 +13,9 @@
 #include "Luau/TypeUtils.h"
 #include "Luau/Unifier2.h"
 
+LUAU_FASTFLAGVARIABLE(LuauDontInPlaceMutateTableType)
+LUAU_FASTFLAGVARIABLE(LuauAllowNonSharedTableTypesInLiteral)
 LUAU_FASTFLAGVARIABLE(LuauBidirectionalInferenceUpcast)
-LUAU_FASTFLAGVARIABLE(LuauBidirectionalInferenceCollectIndexerTypes)
-LUAU_FASTFLAGVARIABLE(LuauBidirectionalFailsafe)
-LUAU_FASTFLAGVARIABLE(LuauBidirectionalInferenceElideAssert)
 
 namespace Luau
 {
@@ -139,13 +138,14 @@ TypeId matchLiteralType(
      * things like replace explicit named properties with indexers as required
      * by the expected type.
      */
-
     if (!isLiteral(expr))
     {
         if (FFlag::LuauBidirectionalInferenceUpcast)
         {
             auto result = subtyping->isSubtype(/*subTy=*/exprType, /*superTy=*/expectedType, unifier->scope);
-            return result.isSubtype ? expectedType : exprType;
+            return result.isSubtype
+                ? expectedType
+                : exprType;
         }
         else
             return exprType;
@@ -154,23 +154,11 @@ TypeId matchLiteralType(
     expectedType = follow(expectedType);
     exprType = follow(exprType);
 
-    if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
+    if (get<AnyType>(expectedType) || get<UnknownType>(expectedType))
     {
-        // The intent of `matchLiteralType` is to upcast values when it's safe
-        // to do so. it's always safe to upcast to `any` or `unknown`, so we
-        // can unconditionally do so here.
-        if (is<AnyType, UnknownType>(expectedType))
-            return expectedType;
+        // "Narrowing" to unknown or any is not going to do anything useful.
+        return exprType;
     }
-    else
-    {
-        if (get<AnyType>(expectedType) || get<UnknownType>(expectedType))
-        {
-            // "Narrowing" to unknown or any is not going to do anything useful.
-            return exprType;
-        }
-    }
-
 
     if (expr->is<AstExprConstantString>())
     {
@@ -252,15 +240,6 @@ TypeId matchLiteralType(
     if (auto exprTable = expr->as<AstExprTable>())
     {
         TableType* const tableTy = getMutable<TableType>(exprType);
-
-        // This can occur if we have an expression like:
-        //
-        //  { x = {}, x = 42 }
-        //
-        // The type of this will be `{ x: number }`
-        if (FFlag::LuauBidirectionalFailsafe && !tableTy)
-            return exprType;
-
         LUAU_ASSERT(tableTy);
 
         const TableType* expectedTableTy = get<TableType>(expectedType);
@@ -287,9 +266,6 @@ TypeId matchLiteralType(
 
         DenseHashSet<AstExprConstantString*> keysToDelete{nullptr};
 
-        DenseHashSet<TypeId> indexerKeyTypes{nullptr};
-        DenseHashSet<TypeId> indexerValueTypes{nullptr};
-
         for (const AstExprTable::Item& item : exprTable->items)
         {
             if (isRecord(item))
@@ -297,20 +273,23 @@ TypeId matchLiteralType(
                 const AstArray<char>& s = item.key->as<AstExprConstantString>()->value;
                 std::string keyStr{s.data, s.data + s.size};
                 auto it = tableTy->props.find(keyStr);
-
-                // This can occur, potentially, if we are re-entrant.
-                if (FFlag::LuauBidirectionalFailsafe && it == tableTy->props.end())
-                    continue;
-
                 LUAU_ASSERT(it != tableTy->props.end());
 
                 Property& prop = it->second;
 
-                // If we encounter a duplcate property, we may have already
-                // set it to be read-only. If that's the case, the only thing
-                // that will definitely crash is trying to access a write
-                // only property.
-                LUAU_ASSERT(!prop.isWriteOnly());
+                if (FFlag::LuauAllowNonSharedTableTypesInLiteral)
+                {
+                    // If we encounter a duplcate property, we may have already
+                    // set it to be read-only. If that's the case, the only thing
+                    // that will definitely crash is trying to access a write
+                    // only property.
+                    LUAU_ASSERT(!prop.isWriteOnly());
+                }
+                else
+                {
+                    // Table literals always initially result in shared read-write types
+                    LUAU_ASSERT(prop.isShared());
+                }
                 TypeId propTy = *prop.readTy;
 
                 auto it2 = expectedTableTy->props.find(keyStr);
@@ -338,20 +317,15 @@ TypeId matchLiteralType(
                             toBlock
                         );
 
-                        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-                        {
-                            indexerKeyTypes.insert(arena->addType(SingletonType{StringSingleton{keyStr}}));
-                            indexerValueTypes.insert(matchedType);
-                        }
+                        if (tableTy->indexer)
+                            unifier->unify(matchedType, tableTy->indexer->indexResultType);
                         else
-                        {
-                            if (tableTy->indexer)
-                                unifier->unify(matchedType, tableTy->indexer->indexResultType);
-                            else
-                                tableTy->indexer = TableIndexer{expectedTableTy->indexer->indexType, matchedType};
-                        }
+                            tableTy->indexer = TableIndexer{expectedTableTy->indexer->indexType, matchedType};
 
-                        keysToDelete.insert(item.key->as<AstExprConstantString>());
+                        if (FFlag::LuauDontInPlaceMutateTableType)
+                            keysToDelete.insert(item.key->as<AstExprConstantString>());
+                        else
+                            tableTy->props.erase(keyStr);
 
                     }
 
@@ -407,16 +381,10 @@ TypeId matchLiteralType(
                 LUAU_ASSERT(matchedType);
 
                 (*astExpectedTypes)[item.value] = matchedType;
-                // NOTE: We do *not* add to the potential indexer types here.
-                // I think this is correct to support something like:
-                //
-                //  { [string]: number, foo: boolean }
-                //
             }
             else if (item.kind == AstExprTable::Item::List)
             {
-                if (!FFlag::LuauBidirectionalInferenceCollectIndexerTypes || !FFlag::LuauBidirectionalInferenceElideAssert)
-                    LUAU_ASSERT(tableTy->indexer);
+                LUAU_ASSERT(tableTy->indexer);
 
                 if (expectedTableTy->indexer)
                 {
@@ -437,18 +405,9 @@ TypeId matchLiteralType(
                         toBlock
                     );
 
-                    if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-                    {
-                        indexerKeyTypes.insert(builtinTypes->numberType);
-                        indexerValueTypes.insert(matchedType);
-                    }
-                    else
-                    {
-                        // if the index result type is the prop type, we can replace it with the matched type here.
-                        if (tableTy->indexer->indexResultType == *propTy)
-                            tableTy->indexer->indexResultType = matchedType;
-                    }
-
+                    // if the index result type is the prop type, we can replace it with the matched type here.
+                    if (tableTy->indexer->indexResultType == *propTy)
+                        tableTy->indexer->indexResultType = matchedType;
                 }
             }
             else if (item.kind == AstExprTable::Item::General)
@@ -470,23 +429,19 @@ TypeId matchLiteralType(
                 // Populate expected types for non-string keys declared with [] (the code below will handle the case where they are strings)
                 if (!item.key->as<AstExprConstantString>() && expectedTableTy->indexer)
                     (*astExpectedTypes)[item.key] = expectedTableTy->indexer->indexType;
-
-                if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-                {
-                    indexerKeyTypes.insert(tKey);
-                    indexerValueTypes.insert(tProp);
-                }
-
             }
             else
                 LUAU_ASSERT(!"Unexpected");
         }
 
-        for (const auto& key : keysToDelete)
+        if (FFlag::LuauDontInPlaceMutateTableType)
         {
-            const AstArray<char>& s = key->value;
-            std::string keyStr{s.data, s.data + s.size};
-            tableTy->props.erase(keyStr);
+            for (const auto& key : keysToDelete)
+            {
+                const AstArray<char>& s = key->value;
+                std::string keyStr{s.data, s.data + s.size};
+                tableTy->props.erase(keyStr);
+            }
         }
 
         // Keys that the expectedType says we should have, but that aren't
@@ -538,39 +493,9 @@ TypeId matchLiteralType(
         // have one too.
         // TODO: If the expected table also has an indexer, we might want to
         // push the expected indexer's types into it.
-        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes && expectedTableTy->indexer)
+        if (expectedTableTy->indexer && !tableTy->indexer)
         {
-            if (indexerValueTypes.size() > 0 && indexerKeyTypes.size() > 0)
-            {
-                TypeId inferredKeyType = builtinTypes->neverType;
-                TypeId inferredValueType = builtinTypes->neverType;
-                for (auto kt: indexerKeyTypes)
-                {
-                    auto simplified = simplifyUnion(builtinTypes, arena, inferredKeyType, kt);
-                    inferredKeyType = simplified.result;
-                }
-                for (auto vt: indexerValueTypes)
-                {
-                    auto simplified = simplifyUnion(builtinTypes, arena, inferredValueType, vt);
-                    inferredValueType = simplified.result;
-                }
-                tableTy->indexer = TableIndexer{inferredKeyType, inferredValueType};
-                auto keyCheck = subtyping->isSubtype(inferredKeyType, expectedTableTy->indexer->indexType, unifier->scope);
-                if (keyCheck.isSubtype)
-                    tableTy->indexer->indexType = expectedTableTy->indexer->indexType;
-                auto valueCheck = subtyping->isSubtype(inferredValueType, expectedTableTy->indexer->indexResultType, unifier->scope);
-                if (valueCheck.isSubtype)
-                    tableTy->indexer->indexResultType = expectedTableTy->indexer->indexResultType;
-            }
-            else
-                LUAU_ASSERT(indexerKeyTypes.empty() && indexerValueTypes.empty());
-        }
-        else
-        {
-            if (expectedTableTy->indexer && !tableTy->indexer)
-            {
-                tableTy->indexer = expectedTableTy->indexer;
-            }
+            tableTy->indexer = expectedTableTy->indexer;
         }
     }
 

Analysis/src/Transpiler.cpp

@@ -10,12 +10,10 @@
 #include <limits>
 #include <math.h>
 
-LUAU_FASTFLAG(LuauStoreCSTData2)
+LUAU_FASTFLAG(LuauStoreCSTData)
 LUAU_FASTFLAG(LuauExtendStatEndPosWithSemicolon)
 LUAU_FASTFLAG(LuauAstTypeGroup3)
 LUAU_FASTFLAG(LuauFixDoBlockEndLocation)
-LUAU_FASTFLAG(LuauParseOptionalAsNode2)
-LUAU_FASTFLAG(LuauFixFunctionWithAttributesStartLocation)
 
 namespace
 {
@@ -168,7 +166,7 @@ struct StringWriter : Writer
 
     void symbol(std::string_view s) override
     {
-        if (FFlag::LuauStoreCSTData2)
+        if (FFlag::LuauStoreCSTData)
         {
             write(s);
         }
@@ -258,7 +256,7 @@ public:
             first = !first;
         else
         {
-            if (FFlag::LuauStoreCSTData2 && commaPosition)
+            if (FFlag::LuauStoreCSTData && commaPosition)
             {
                 writer.advance(*commaPosition);
                 commaPosition++;
@@ -273,43 +271,6 @@ private:
     const Position* commaPosition;
 };
 
-class ArgNameInserter
-{
-public:
-    ArgNameInserter(Writer& w, AstArray<std::optional<AstArgumentName>> names, AstArray<std::optional<Position>> colonPositions)
-        : writer(w)
-        , names(names)
-        , colonPositions(colonPositions)
-    {
-    }
-
-    void operator()()
-    {
-        if (idx < names.size)
-        {
-            const auto name = names.data[idx];
-            if (name.has_value())
-            {
-                writer.advance(name->second.begin);
-                writer.identifier(name->first.value);
-                if (idx < colonPositions.size)
-                {
-                    LUAU_ASSERT(colonPositions.data[idx].has_value());
-                    writer.advance(*colonPositions.data[idx]);
-                }
-                writer.symbol(":");
-            }
-        }
-        idx++;
-    }
-
-private:
-    Writer& writer;
-    AstArray<std::optional<AstArgumentName>> names;
-    AstArray<std::optional<Position>> colonPositions;
-    size_t idx = 0;
-};
-
 struct Printer_DEPRECATED
 {
     explicit Printer_DEPRECATED(Writer& writer)
@@ -1230,18 +1191,9 @@ struct Printer_DEPRECATED
                 AstType* l = a->types.data[0];
                 AstType* r = a->types.data[1];
 
-                if (FFlag::LuauParseOptionalAsNode2)
-                {
-                    auto lta = l->as<AstTypeReference>();
-                    if (lta && lta->name == "nil" && !r->is<AstTypeOptional>())
-                        std::swap(l, r);
-                }
-                else
-                {
-                    auto lta = l->as<AstTypeReference>();
-                    if (lta && lta->name == "nil")
-                        std::swap(l, r);
-                }
+                auto lta = l->as<AstTypeReference>();
+                if (lta && lta->name == "nil")
+                    std::swap(l, r);
 
                 // it's still possible that we had a (T | U) or (T | nil) and not (nil | T)
                 auto rta = r->as<AstTypeReference>();
@@ -1264,15 +1216,6 @@ struct Printer_DEPRECATED
 
             for (size_t i = 0; i < a->types.size; ++i)
             {
-                if (FFlag::LuauParseOptionalAsNode2)
-                {
-                    if (a->types.data[i]->is<AstTypeOptional>())
-                    {
-                        writer.symbol("?");
-                        continue;
-                    }
-                }
-
                 if (i > 0)
                 {
                     writer.maybeSpace(a->types.data[i]->location.begin, 2);
@@ -1369,7 +1312,7 @@ struct Printer
         }
     }
 
-    void visualizeTypePackAnnotation(AstTypePack& annotation, bool forVarArg)
+    void visualizeTypePackAnnotation(const AstTypePack& annotation, bool forVarArg)
     {
         advance(annotation.location.begin);
         if (const AstTypePackVariadic* variadicTp = annotation.as<AstTypePackVariadic>())
@@ -1379,22 +1322,15 @@ struct Printer
 
             visualizeTypeAnnotation(*variadicTp->variadicType);
         }
-        else if (AstTypePackGeneric* genericTp = annotation.as<AstTypePackGeneric>())
+        else if (const AstTypePackGeneric* genericTp = annotation.as<AstTypePackGeneric>())
         {
             writer.symbol(genericTp->genericName.value);
-            if (const auto cstNode = lookupCstNode<CstTypePackGeneric>(genericTp))
-                advance(cstNode->ellipsisPosition);
             writer.symbol("...");
         }
-        else if (AstTypePackExplicit* explicitTp = annotation.as<AstTypePackExplicit>())
+        else if (const AstTypePackExplicit* explicitTp = annotation.as<AstTypePackExplicit>())
         {
             LUAU_ASSERT(!forVarArg);
-            if (const auto cstNode = lookupCstNode<CstTypePackExplicit>(explicitTp))
-                visualizeTypeList(
-                    explicitTp->typeList, true, cstNode->openParenthesesPosition, cstNode->closeParenthesesPosition, cstNode->commaPositions
-                );
-            else
-                visualizeTypeList(explicitTp->typeList, true);
+            visualizeTypeList(explicitTp->typeList, true);
         }
         else
         {
@@ -1402,37 +1338,19 @@ struct Printer
         }
     }
 
-    void visualizeNamedTypeList(
-        const AstTypeList& list,
-        bool unconditionallyParenthesize,
-        std::optional<Position> openParenthesesPosition,
-        std::optional<Position> closeParenthesesPosition,
-        AstArray<Position> commaPositions,
-        AstArray<std::optional<AstArgumentName>> argNames,
-        AstArray<std::optional<Position>> argNamesColonPositions
-    )
+    void visualizeTypeList(const AstTypeList& list, bool unconditionallyParenthesize)
     {
         size_t typeCount = list.types.size + (list.tailType != nullptr ? 1 : 0);
         if (typeCount == 0)
         {
-            if (openParenthesesPosition)
-                advance(*openParenthesesPosition);
             writer.symbol("(");
-            if (closeParenthesesPosition)
-                advance(*closeParenthesesPosition);
             writer.symbol(")");
         }
         else if (typeCount == 1)
         {
             bool shouldParenthesize = unconditionallyParenthesize && (list.types.size == 0 || !list.types.data[0]->is<AstTypeGroup>());
             if (FFlag::LuauAstTypeGroup3 ? shouldParenthesize : unconditionallyParenthesize)
-            {
-                if (openParenthesesPosition)
-                    advance(*openParenthesesPosition);
                 writer.symbol("(");
-            }
-
-            ArgNameInserter(writer, argNames, argNamesColonPositions)();
 
             // Only variadic tail
             if (list.types.size == 0)
@@ -1445,50 +1363,33 @@ struct Printer
             }
 
             if (FFlag::LuauAstTypeGroup3 ? shouldParenthesize : unconditionallyParenthesize)
-            {
-                if (closeParenthesesPosition)
-                    advance(*closeParenthesesPosition);
                 writer.symbol(")");
-            }
         }
         else
         {
-            if (openParenthesesPosition)
-                advance(*openParenthesesPosition);
             writer.symbol("(");
 
-            CommaSeparatorInserter comma(writer, commaPositions.size > 0 ? commaPositions.begin() : nullptr);
-            ArgNameInserter argName(writer, argNames, argNamesColonPositions);
+            bool first = true;
             for (const auto& el : list.types)
             {
-                comma();
-                argName();
+                if (first)
+                    first = false;
+                else
+                    writer.symbol(",");
+
                 visualizeTypeAnnotation(*el);
             }
 
             if (list.tailType)
             {
-                comma();
+                writer.symbol(",");
                 visualizeTypePackAnnotation(*list.tailType, false);
             }
 
-            if (closeParenthesesPosition)
-                advance(*closeParenthesesPosition);
             writer.symbol(")");
         }
     }
 
-    void visualizeTypeList(
-        const AstTypeList& list,
-        bool unconditionallyParenthesize,
-        std::optional<Position> openParenthesesPosition = std::nullopt,
-        std::optional<Position> closeParenthesesPosition = std::nullopt,
-        AstArray<Position> commaPositions = {}
-    )
-    {
-        visualizeNamedTypeList(list, unconditionallyParenthesize, openParenthesesPosition, closeParenthesesPosition, commaPositions, {}, {});
-    }
-
     bool isIntegerish(double d)
     {
         if (d <= std::numeric_limits<int>::max() && d >= std::numeric_limits<int>::min())
@@ -1499,14 +1400,13 @@ struct Printer
 
     void visualize(AstExpr& expr)
     {
-        if (!expr.is<AstExprFunction>() || FFlag::LuauFixFunctionWithAttributesStartLocation)
-            advance(expr.location.begin);
+        advance(expr.location.begin);
 
         if (const auto& a = expr.as<AstExprGroup>())
         {
             writer.symbol("(");
             visualize(*a->expr);
-            advanceBefore(a->location.end, 1);
+            advance(Position{a->location.end.line, a->location.end.column - 1});
             writer.symbol(")");
         }
         else if (expr.is<AstExprConstantNil>())
@@ -1634,17 +1534,6 @@ struct Printer
         }
         else if (const auto& a = expr.as<AstExprFunction>())
         {
-            for (const auto& attribute : a->attributes)
-                visualizeAttribute(*attribute);
-            if (FFlag::LuauFixFunctionWithAttributesStartLocation)
-            {
-                if (const auto cstNode = lookupCstNode<CstExprFunction>(a))
-                    advance(cstNode->functionKeywordPosition);
-            }
-            else
-            {
-                advance(a->location.begin);
-            }
             writer.keyword("function");
             visualizeFunctionBody(*a);
         }
@@ -1886,18 +1775,9 @@ struct Printer
         writer.advance(newPos);
     }
 
-    void advanceBefore(const Position& newPos, unsigned int tokenLength)
-    {
-        if (newPos.column >= tokenLength)
-            advance(Position{newPos.line, newPos.column - tokenLength});
-        else
-            advance(newPos);
-    }
-
     void visualize(AstStat& program)
     {
-        if ((!program.is<AstStatLocalFunction>() && !program.is<AstStatFunction>()) || FFlag::LuauFixFunctionWithAttributesStartLocation)
-            advance(program.location.begin);
+        advance(program.location.begin);
 
         if (const auto& block = program.as<AstStatBlock>())
         {
@@ -1937,8 +1817,8 @@ struct Printer
             visualizeBlock(*a->body);
             if (const auto cstNode = lookupCstNode<CstStatRepeat>(a))
                 writer.advance(cstNode->untilPosition);
-            else
-                advanceBefore(a->condition->location.begin, 6);
+            else if (a->condition->location.begin.column > 5)
+                writer.advance(Position{a->condition->location.begin.line, a->condition->location.begin.column - 6});
             writer.keyword("until");
             visualize(*a->condition);
         }
@@ -2134,36 +2014,13 @@ struct Printer
         }
         else if (const auto& a = program.as<AstStatFunction>())
         {
-            for (const auto& attribute : a->func->attributes)
-                visualizeAttribute(*attribute);
-            if (FFlag::LuauFixFunctionWithAttributesStartLocation)
-            {
-                if (const auto cstNode = lookupCstNode<CstStatFunction>(a))
-                    advance(cstNode->functionKeywordPosition);
-            }
-            else
-            {
-                advance(a->location.begin);
-            }
             writer.keyword("function");
             visualize(*a->name);
             visualizeFunctionBody(*a->func);
         }
         else if (const auto& a = program.as<AstStatLocalFunction>())
         {
-            for (const auto& attribute : a->func->attributes)
-                visualizeAttribute(*attribute);
-
             const auto cstNode = lookupCstNode<CstStatLocalFunction>(a);
-            if (FFlag::LuauFixFunctionWithAttributesStartLocation)
-            {
-                if (cstNode)
-                    advance(cstNode->localKeywordPosition);
-            }
-            else
-            {
-                advance(a->location.begin);
-            }
 
             writer.keyword("local");
 
@@ -2264,20 +2121,7 @@ struct Printer
         {
             if (writeTypes)
             {
-                const auto cstNode = lookupCstNode<CstStatTypeFunction>(t);
-                if (t->exported)
-                    writer.keyword("export");
-                if (cstNode)
-                    advance(cstNode->typeKeywordPosition);
-                else
-                    writer.space();
-                writer.keyword("type");
-                if (cstNode)
-                    advance(cstNode->functionKeywordPosition);
-                else
-                    writer.space();
-                writer.keyword("function");
-                advance(t->nameLocation.begin);
+                writer.keyword("type function");
                 writer.identifier(t->name.value);
                 visualizeFunctionBody(*t->body);
             }
@@ -2307,23 +2151,17 @@ struct Printer
 
         if (program.hasSemicolon)
         {
-            if (FFlag::LuauStoreCSTData2)
-                advanceBefore(program.location.end, 1);
+            if (FFlag::LuauStoreCSTData)
+                advance(Position{program.location.end.line, program.location.end.column - 1});
             writer.symbol(";");
         }
     }
 
     void visualizeFunctionBody(AstExprFunction& func)
     {
-        const auto cstNode = lookupCstNode<CstExprFunction>(&func);
-
-        // TODO(CLI-139347): need to handle return type (incl. parentheses of return type)
-
         if (func.generics.size > 0 || func.genericPacks.size > 0)
         {
-            CommaSeparatorInserter comma(writer, cstNode ? cstNode->genericsCommaPositions.begin() : nullptr);
-            if (cstNode)
-                advance(cstNode->openGenericsPosition);
+            CommaSeparatorInserter comma(writer);
             writer.symbol("<");
             for (const auto& o : func.generics)
             {
@@ -2338,19 +2176,13 @@ struct Printer
 
                 writer.advance(o->location.begin);
                 writer.identifier(o->name.value);
-                if (const auto* genericTypePackCstNode = lookupCstNode<CstGenericTypePack>(o))
-                    advance(genericTypePackCstNode->ellipsisPosition);
                 writer.symbol("...");
             }
-            if (cstNode)
-                advance(cstNode->closeGenericsPosition);
             writer.symbol(">");
         }
 
-        if (func.argLocation)
-            advance(func.argLocation->begin);
         writer.symbol("(");
-        CommaSeparatorInserter comma(writer, cstNode ? cstNode->argsCommaPositions.begin() : nullptr);
+        CommaSeparatorInserter comma(writer);
 
         for (size_t i = 0; i < func.args.size; ++i)
         {
@@ -2380,14 +2212,10 @@ struct Printer
             }
         }
 
-        if (func.argLocation)
-            advanceBefore(func.argLocation->end, 1);
         writer.symbol(")");
 
         if (writeTypes && func.returnAnnotation)
         {
-            if (cstNode)
-                advance(cstNode->returnSpecifierPosition);
             writer.symbol(":");
             writer.space();
 
@@ -2473,23 +2301,6 @@ struct Printer
         }
     }
 
-    void visualizeAttribute(AstAttr& attribute)
-    {
-        advance(attribute.location.begin);
-        switch (attribute.type)
-        {
-        case AstAttr::Checked:
-            writer.keyword("@checked");
-            break;
-        case AstAttr::Native:
-            writer.keyword("@native");
-            break;
-        case AstAttr::Deprecated:
-            writer.keyword("@deprecated");
-            break;
-        }
-    }
-
     void visualizeTypeAnnotation(AstType& typeAnnotation)
     {
         advance(typeAnnotation.location.begin);
@@ -2529,13 +2340,9 @@ struct Printer
         }
         else if (const auto& a = typeAnnotation.as<AstTypeFunction>())
         {
-            const auto cstNode = lookupCstNode<CstTypeFunction>(a);
-
             if (a->generics.size > 0 || a->genericPacks.size > 0)
             {
-                CommaSeparatorInserter comma(writer, cstNode ? cstNode->genericsCommaPositions.begin() : nullptr);
-                if (cstNode)
-                    advance(cstNode->openGenericsPosition);
+                CommaSeparatorInserter comma(writer);
                 writer.symbol("<");
                 for (const auto& o : a->generics)
                 {
@@ -2550,29 +2357,15 @@ struct Printer
 
                     writer.advance(o->location.begin);
                     writer.identifier(o->name.value);
-                    if (const auto* genericTypePackCstNode = lookupCstNode<CstGenericTypePack>(o))
-                        advance(genericTypePackCstNode->ellipsisPosition);
                     writer.symbol("...");
                 }
-                if (cstNode)
-                    advance(cstNode->closeGenericsPosition);
                 writer.symbol(">");
             }
 
             {
-                visualizeNamedTypeList(
-                    a->argTypes,
-                    true,
-                    cstNode ? std::make_optional(cstNode->openArgsPosition) : std::nullopt,
-                    cstNode ? std::make_optional(cstNode->closeArgsPosition) : std::nullopt,
-                    cstNode ? cstNode->argumentsCommaPositions : Luau::AstArray<Position>{},
-                    a->argNames,
-                    cstNode ? cstNode->argumentNameColonPositions : Luau::AstArray<std::optional<Position>>{}
-                );
+                visualizeTypeList(a->argTypes, true);
             }
 
-            if (cstNode)
-                advance(cstNode->returnArrowPosition);
             writer.symbol("->");
             visualizeTypeList(a->returnTypes, true);
         }
@@ -2734,25 +2527,14 @@ struct Printer
         }
         else if (const auto& a = typeAnnotation.as<AstTypeUnion>())
         {
-            const auto cstNode = lookupCstNode<CstTypeUnion>(a);
-
-            if (!cstNode && a->types.size == 2)
+            if (a->types.size == 2)
             {
                 AstType* l = a->types.data[0];
                 AstType* r = a->types.data[1];
 
-                if (FFlag::LuauParseOptionalAsNode2)
-                {
-                    auto lta = l->as<AstTypeReference>();
-                    if (lta && lta->name == "nil" && !r->is<AstTypeOptional>())
-                        std::swap(l, r);
-                }
-                else
-                {
-                    auto lta = l->as<AstTypeReference>();
-                    if (lta && lta->name == "nil")
-                        std::swap(l, r);
-                }
+                auto lta = l->as<AstTypeReference>();
+                if (lta && lta->name == "nil")
+                    std::swap(l, r);
 
                 // it's still possible that we had a (T | U) or (T | nil) and not (nil | T)
                 auto rta = r->as<AstTypeReference>();
@@ -2773,39 +2555,15 @@ struct Printer
                 }
             }
 
-            if (cstNode && cstNode->leadingPosition)
-            {
-                advance(*cstNode->leadingPosition);
-                writer.symbol("|");
-            }
-
-            size_t separatorIndex = 0;
             for (size_t i = 0; i < a->types.size; ++i)
             {
-                if (FFlag::LuauParseOptionalAsNode2)
-                {
-                    if (const auto optional = a->types.data[i]->as<AstTypeOptional>())
-                    {
-                        advance(optional->location.begin);
-                        writer.symbol("?");
-                        continue;
-                    }
-                }
-
                 if (i > 0)
                 {
-                    if (cstNode && FFlag::LuauParseOptionalAsNode2)
-                    {
-                        // separatorIndex is only valid if `?` is handled as an AstTypeOptional
-                        advance(cstNode->separatorPositions.data[separatorIndex]);
-                        separatorIndex++;
-                    }
-                    else
-                        writer.maybeSpace(a->types.data[i]->location.begin, 2);
+                    writer.maybeSpace(a->types.data[i]->location.begin, 2);
                     writer.symbol("|");
                 }
 
-                bool wrap = !cstNode && (a->types.data[i]->as<AstTypeIntersection>() || a->types.data[i]->as<AstTypeFunction>());
+                bool wrap = a->types.data[i]->as<AstTypeIntersection>() || a->types.data[i]->as<AstTypeFunction>();
 
                 if (wrap)
                     writer.symbol("(");
@@ -2818,27 +2576,15 @@ struct Printer
         }
         else if (const auto& a = typeAnnotation.as<AstTypeIntersection>())
         {
-            const auto cstNode = lookupCstNode<CstTypeIntersection>(a);
-
-            // If the sizes are equal, we know there is a leading & token
-            if (cstNode && cstNode->leadingPosition)
-            {
-                advance(*cstNode->leadingPosition);
-                writer.symbol("&");
-            }
-
             for (size_t i = 0; i < a->types.size; ++i)
             {
                 if (i > 0)
                 {
-                    if (cstNode)
-                        advance(cstNode->separatorPositions.data[i - 1]);
-                    else
-                        writer.maybeSpace(a->types.data[i]->location.begin, 2);
+                    writer.maybeSpace(a->types.data[i]->location.begin, 2);
                     writer.symbol("&");
                 }
 
-                bool wrap = !cstNode && (a->types.data[i]->as<AstTypeUnion>() || a->types.data[i]->as<AstTypeFunction>());
+                bool wrap = a->types.data[i]->as<AstTypeUnion>() || a->types.data[i]->as<AstTypeFunction>();
 
                 if (wrap)
                     writer.symbol("(");
@@ -2853,7 +2599,7 @@ struct Printer
         {
             writer.symbol("(");
             visualizeTypeAnnotation(*a->type);
-            advanceBefore(a->location.end, 1);
+            advance(Position{a->location.end.line, a->location.end.column - 1});
             writer.symbol(")");
         }
         else if (const auto& a = typeAnnotation.as<AstTypeSingletonBool>())
@@ -2887,7 +2633,7 @@ std::string toString(AstNode* node)
     StringWriter writer;
     writer.pos = node->location.begin;
 
-    if (FFlag::LuauStoreCSTData2)
+    if (FFlag::LuauStoreCSTData)
     {
         Printer printer(writer, CstNodeMap{nullptr});
         printer.writeTypes = true;
@@ -2923,7 +2669,7 @@ void dump(AstNode* node)
 std::string transpile(AstStatBlock& block, const CstNodeMap& cstNodeMap)
 {
     StringWriter writer;
-    if (FFlag::LuauStoreCSTData2)
+    if (FFlag::LuauStoreCSTData)
     {
         Printer(writer, cstNodeMap).visualizeBlock(block);
     }
@@ -2937,7 +2683,7 @@ std::string transpile(AstStatBlock& block, const CstNodeMap& cstNodeMap)
 std::string transpileWithTypes(AstStatBlock& block, const CstNodeMap& cstNodeMap)
 {
     StringWriter writer;
-    if (FFlag::LuauStoreCSTData2)
+    if (FFlag::LuauStoreCSTData)
     {
         Printer printer(writer, cstNodeMap);
         printer.writeTypes = true;

Analysis/src/TxnLog.cpp

@@ -407,6 +407,41 @@ PendingTypePack* TxnLog::changeLevel(TypePackId tp, TypeLevel newLevel)
     return newTp;
 }
 
+PendingType* TxnLog::changeScope(TypeId ty, NotNull<Scope> newScope)
+{
+    LUAU_ASSERT(get<FreeType>(ty) || get<TableType>(ty) || get<FunctionType>(ty));
+
+    PendingType* newTy = queue(ty);
+    if (FreeType* ftv = Luau::getMutable<FreeType>(newTy))
+    {
+        ftv->scope = newScope;
+    }
+    else if (TableType* ttv = Luau::getMutable<TableType>(newTy))
+    {
+        LUAU_ASSERT(ttv->state == TableState::Free || ttv->state == TableState::Generic);
+        ttv->scope = newScope;
+    }
+    else if (FunctionType* ftv = Luau::getMutable<FunctionType>(newTy))
+    {
+        ftv->scope = newScope;
+    }
+
+    return newTy;
+}
+
+PendingTypePack* TxnLog::changeScope(TypePackId tp, NotNull<Scope> newScope)
+{
+    LUAU_ASSERT(get<FreeTypePack>(tp));
+
+    PendingTypePack* newTp = queue(tp);
+    if (FreeTypePack* ftp = Luau::getMutable<FreeTypePack>(newTp))
+    {
+        ftp->scope = newScope;
+    }
+
+    return newTp;
+}
+
 PendingType* TxnLog::changeIndexer(TypeId ty, std::optional<TableIndexer> indexer)
 {
     LUAU_ASSERT(get<TableType>(ty));

Analysis/src/Type.cpp

@@ -630,6 +630,23 @@ FunctionType::FunctionType(TypeLevel level, TypePackId argTypes, TypePackId retT
 {
 }
 
+FunctionType::FunctionType(
+    TypeLevel level,
+    Scope* scope,
+    TypePackId argTypes,
+    TypePackId retTypes,
+    std::optional<FunctionDefinition> defn,
+    bool hasSelf
+)
+    : definition(std::move(defn))
+    , level(level)
+    , scope(scope)
+    , argTypes(argTypes)
+    , retTypes(retTypes)
+    , hasSelf(hasSelf)
+{
+}
+
 FunctionType::FunctionType(
     std::vector<TypeId> generics,
     std::vector<TypePackId> genericPacks,
@@ -666,6 +683,27 @@ FunctionType::FunctionType(
 {
 }
 
+FunctionType::FunctionType(
+    TypeLevel level,
+    Scope* scope,
+    std::vector<TypeId> generics,
+    std::vector<TypePackId> genericPacks,
+    TypePackId argTypes,
+    TypePackId retTypes,
+    std::optional<FunctionDefinition> defn,
+    bool hasSelf
+)
+    : definition(std::move(defn))
+    , generics(generics)
+    , genericPacks(genericPacks)
+    , level(level)
+    , scope(scope)
+    , argTypes(argTypes)
+    , retTypes(retTypes)
+    , hasSelf(hasSelf)
+{
+}
+
 Property::Property() {}
 
 Property::Property(

Analysis/src/TypeAttach.cpp

@@ -13,8 +13,6 @@
 
 #include <string>
 
-LUAU_FASTFLAG(LuauStoreCSTData2)
-
 static char* allocateString(Luau::Allocator& allocator, std::string_view contents)
 {
     char* result = (char*)allocator.allocate(contents.size() + 1);
@@ -307,8 +305,7 @@ public:
             std::optional<AstArgumentName>* arg = &argNames.data[i++];
 
             if (el)
-                new (arg)
-                    std::optional<AstArgumentName>(AstArgumentName(AstName(el->name.c_str()), FFlag::LuauStoreCSTData2 ? Location() : el->location));
+                new (arg) std::optional<AstArgumentName>(AstArgumentName(AstName(el->name.c_str()), el->location));
             else
                 new (arg) std::optional<AstArgumentName>();
         }

Analysis/src/TypeChecker2.cpp

@@ -26,14 +26,10 @@
 #include "Luau/VisitType.h"
 
 #include <algorithm>
-#include <sstream>
 
 LUAU_FASTFLAG(DebugLuauMagicTypes)
 
 LUAU_FASTFLAG(LuauFreeTypesMustHaveBounds)
-LUAU_FASTFLAGVARIABLE(LuauImproveTypePathsInErrors)
-LUAU_FASTFLAG(LuauUserTypeFunTypecheck)
-LUAU_FASTFLAGVARIABLE(LuauTypeCheckerAcceptNumberConcats)
 
 namespace Luau
 {
@@ -1205,8 +1201,7 @@ void TypeChecker2::visit(AstStatTypeAlias* stat)
 
 void TypeChecker2::visit(AstStatTypeFunction* stat)
 {
-    if (FFlag::LuauUserTypeFunTypecheck)
-        visit(stat->body);
+    // TODO: add type checking for user-defined type functions
 }
 
 void TypeChecker2::visit(AstTypeList types)
@@ -2230,21 +2225,10 @@ TypeId TypeChecker2::visit(AstExprBinary* expr, AstNode* overrideKey)
 
         return builtinTypes->numberType;
     case AstExprBinary::Op::Concat:
-    {
-        if (FFlag::LuauTypeCheckerAcceptNumberConcats)
-        {
-            const TypeId numberOrString = module->internalTypes.addType(UnionType{{builtinTypes->numberType, builtinTypes->stringType}});
-            testIsSubtype(leftType, numberOrString, expr->left->location);
-            testIsSubtype(rightType, numberOrString, expr->right->location);
-        }
-        else
-        {
-            testIsSubtype(leftType, builtinTypes->stringType, expr->left->location);
-            testIsSubtype(rightType, builtinTypes->stringType, expr->right->location);
-        }
+        testIsSubtype(leftType, builtinTypes->stringType, expr->left->location);
+        testIsSubtype(rightType, builtinTypes->stringType, expr->right->location);
 
         return builtinTypes->stringType;
-    }
     case AstExprBinary::Op::CompareGe:
     case AstExprBinary::Op::CompareGt:
     case AstExprBinary::Op::CompareLe:
@@ -2717,61 +2701,20 @@ Reasonings TypeChecker2::explainReasonings_(TID subTy, TID superTy, Location loc
         if (!subLeafTy && !superLeafTy && !subLeafTp && !superLeafTp)
             ice->ice("Subtyping test returned a reasoning where one path ends at a type and the other ends at a pack.", location);
 
-        if (FFlag::LuauImproveTypePathsInErrors)
-        {
-            std::string relation = "a subtype of";
-            if (reasoning.variance == SubtypingVariance::Invariant)
-                relation = "exactly";
-            else if (reasoning.variance == SubtypingVariance::Contravariant)
-                relation = "a supertype of";
+        std::string relation = "a subtype of";
+        if (reasoning.variance == SubtypingVariance::Invariant)
+            relation = "exactly";
+        else if (reasoning.variance == SubtypingVariance::Contravariant)
+            relation = "a supertype of";
 
-            std::string subLeafAsString = toString(subLeaf);
-            // if the string is empty, it must be an empty type pack
-            if (subLeafAsString.empty())
-                subLeafAsString = "()";
-
-            std::string superLeafAsString = toString(superLeaf);
-            // if the string is empty, it must be an empty type pack
-            if (superLeafAsString.empty())
-                superLeafAsString = "()";
-
-            std::stringstream baseReasonBuilder;
-            baseReasonBuilder << "`" << subLeafAsString << "` is not " << relation << " `" << superLeafAsString << "`";
-            std::string baseReason = baseReasonBuilder.str();
-
-            std::stringstream reason;
-
-            if (reasoning.subPath == reasoning.superPath)
-                reason << toStringHuman(reasoning.subPath) << "`" << subLeafAsString << "` in the former type and `" << superLeafAsString
-                       << "` in the latter type, and " << baseReason;
-            else if (!reasoning.subPath.empty() && !reasoning.superPath.empty())
-                reason << toStringHuman(reasoning.subPath) << "`" << subLeafAsString << "` and " << toStringHuman(reasoning.superPath) << "`"
-                       << superLeafAsString << "`, and " << baseReason;
-            else if (!reasoning.subPath.empty())
-                reason << toStringHuman(reasoning.subPath) << "`" << subLeafAsString << "`, which is not " << relation << " `" << superLeafAsString
-                       << "`";
-            else
-                reason << toStringHuman(reasoning.superPath) << "`" << superLeafAsString << "`, and " << baseReason;
-
-            reasons.push_back(reason.str());
-        }
+        std::string reason;
+        if (reasoning.subPath == reasoning.superPath)
+            reason = "at " + toString(reasoning.subPath) + ", " + toString(subLeaf) + " is not " + relation + " " + toString(superLeaf);
         else
-        {
-            std::string relation = "a subtype of";
-            if (reasoning.variance == SubtypingVariance::Invariant)
-                relation = "exactly";
-            else if (reasoning.variance == SubtypingVariance::Contravariant)
-                relation = "a supertype of";
+            reason = "type " + toString(subTy) + toString(reasoning.subPath, /* prefixDot */ true) + " (" + toString(subLeaf) + ") is not " +
+                     relation + " " + toString(superTy) + toString(reasoning.superPath, /* prefixDot */ true) + " (" + toString(superLeaf) + ")";
 
-            std::string reason;
-            if (reasoning.subPath == reasoning.superPath)
-                reason = "at " + toString(reasoning.subPath) + ", " + toString(subLeaf) + " is not " + relation + " " + toString(superLeaf);
-            else
-                reason = "type " + toString(subTy) + toString(reasoning.subPath, /* prefixDot */ true) + " (" + toString(subLeaf) + ") is not " +
-                         relation + " " + toString(superTy) + toString(reasoning.superPath, /* prefixDot */ true) + " (" + toString(superLeaf) + ")";
-
-            reasons.push_back(reason);
-        }
+        reasons.push_back(reason);
 
         // if we haven't already proved this isn't suppressing, we have to keep checking.
         if (suppressed)

Analysis/src/TypeFunctionRuntime.cpp

@@ -13,7 +13,11 @@
 #include <set>
 #include <vector>
 
+LUAU_FASTFLAGVARIABLE(LuauTypeFunFixHydratedClasses)
 LUAU_DYNAMIC_FASTINT(LuauTypeFunctionSerdeIterationLimit)
+LUAU_FASTFLAGVARIABLE(LuauTypeFunSingletonEquality)
+LUAU_FASTFLAGVARIABLE(LuauUserTypeFunTypeofReturnsType)
+LUAU_FASTFLAGVARIABLE(LuauTypeFunPrintFix)
 LUAU_FASTFLAGVARIABLE(LuauTypeFunReadWriteParents)
 
 namespace Luau
@@ -1613,8 +1617,11 @@ void registerTypeUserData(lua_State* L)
     // Create and register metatable for type userdata
     luaL_newmetatable(L, "type");
 
-    lua_pushstring(L, "type");
-    lua_setfield(L, -2, "__type");
+    if (FFlag::LuauUserTypeFunTypeofReturnsType)
+    {
+        lua_pushstring(L, "type");
+        lua_setfield(L, -2, "__type");
+    }
 
     // Protect metatable from being changed
     lua_pushstring(L, "The metatable is locked");
@@ -1655,7 +1662,10 @@ static int print(lua_State* L)
         const char* s = luaL_tolstring(L, i, &l); // convert to string using __tostring et al
         if (i > 1)
         {
-            result.append(1, '\t');
+            if (FFlag::LuauTypeFunPrintFix)
+                result.append(1, '\t');
+            else
+                result.append('\t', 1);
         }
         result.append(s, l);
         lua_pop(L, 1);
@@ -1748,14 +1758,14 @@ bool areEqual(SeenSet& seen, const TypeFunctionSingletonType& lhs, const TypeFun
 
     {
         const TypeFunctionBooleanSingleton* lp = get<TypeFunctionBooleanSingleton>(&lhs);
-        const TypeFunctionBooleanSingleton* rp = get<TypeFunctionBooleanSingleton>(&rhs);
+        const TypeFunctionBooleanSingleton* rp = get<TypeFunctionBooleanSingleton>(FFlag::LuauTypeFunSingletonEquality ? &rhs : &lhs);
         if (lp && rp)
             return lp->value == rp->value;
     }
 
     {
         const TypeFunctionStringSingleton* lp = get<TypeFunctionStringSingleton>(&lhs);
-        const TypeFunctionStringSingleton* rp = get<TypeFunctionStringSingleton>(&rhs);
+        const TypeFunctionStringSingleton* rp = get<TypeFunctionStringSingleton>(FFlag::LuauTypeFunSingletonEquality ? &rhs : &lhs);
         if (lp && rp)
             return lp->value == rp->value;
     }
@@ -1908,7 +1918,10 @@ bool areEqual(SeenSet& seen, const TypeFunctionClassType& lhs, const TypeFunctio
     if (seenSetContains(seen, &lhs, &rhs))
         return true;
 
-    return lhs.classTy == rhs.classTy;
+    if (FFlag::LuauTypeFunFixHydratedClasses)
+        return lhs.classTy == rhs.classTy;
+    else
+        return lhs.name_DEPRECATED == rhs.name_DEPRECATED;
 }
 
 bool areEqual(SeenSet& seen, const TypeFunctionType& lhs, const TypeFunctionType& rhs)

Analysis/src/TypeFunctionRuntimeBuilder.cpp

@@ -19,6 +19,7 @@
 // used to control the recursion limit of any operations done by user-defined type functions
 // currently, controls serialization, deserialization, and `type.copy`
 LUAU_DYNAMIC_FASTINTVARIABLE(LuauTypeFunctionSerdeIterationLimit, 100'000);
+LUAU_FASTFLAG(LuauTypeFunFixHydratedClasses)
 LUAU_FASTFLAG(LuauTypeFunReadWriteParents)
 
 namespace Luau
@@ -208,11 +209,19 @@ private:
         }
         else if (auto c = get<ClassType>(ty))
         {
-            // Since there aren't any new class types being created in type functions, we will deserialize by using a direct reference to the original
-            // class
-            target = typeFunctionRuntime->typeArena.allocate(
-                TypeFunctionClassType{{}, std::nullopt, std::nullopt, std::nullopt, std::nullopt, std::nullopt, ty}
-            );
+            if (FFlag::LuauTypeFunFixHydratedClasses)
+            {
+                // Since there aren't any new class types being created in type functions, we will deserialize by using a direct reference to the
+                // original class
+                target = typeFunctionRuntime->typeArena.allocate(TypeFunctionClassType{{}, std::nullopt, std::nullopt, std::nullopt, std::nullopt, std::nullopt, ty});
+            }
+            else
+            {
+                state->classesSerialized_DEPRECATED[c->name] = ty;
+                target = typeFunctionRuntime->typeArena.allocate(
+                    TypeFunctionClassType{{}, std::nullopt, std::nullopt, std::nullopt, std::nullopt, std::nullopt, /* classTy */ nullptr, c->name}
+                );
+            }
         }
         else if (auto g = get<GenericType>(ty))
         {
@@ -704,7 +713,17 @@ private:
         }
         else if (auto c = get<TypeFunctionClassType>(ty))
         {
-            target = c->classTy;
+            if (FFlag::LuauTypeFunFixHydratedClasses)
+            {
+                target = c->classTy;
+            }
+            else
+            {
+                if (auto result = state->classesSerialized_DEPRECATED.find(c->name_DEPRECATED))
+                    target = *result;
+                else
+                    state->ctx->ice->ice("Deserializing user defined type function arguments: mysterious class type is being deserialized");
+            }
         }
         else if (auto g = get<TypeFunctionGenericType>(ty))
         {

Analysis/src/TypeInfer.cpp

@@ -34,7 +34,8 @@ LUAU_FASTFLAGVARIABLE(DebugLuauFreezeDuringUnification)
 LUAU_FASTFLAG(LuauInstantiateInSubtyping)
 LUAU_FASTFLAG(LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
 LUAU_FASTFLAG(LuauFreeTypesMustHaveBounds)
-LUAU_FASTFLAG(LuauRetainDefinitionAliasLocations)
+
+LUAU_FASTFLAG(LuauModuleHoldsAstRoot)
 
 namespace Luau
 {
@@ -255,7 +256,8 @@ ModulePtr TypeChecker::checkWithoutRecursionCheck(const SourceModule& module, Mo
     currentModule->type = module.type;
     currentModule->allocator = module.allocator;
     currentModule->names = module.names;
-    currentModule->root = module.root;
+    if (FFlag::LuauModuleHoldsAstRoot)
+        currentModule->root = module.root;
 
     iceHandler->moduleName = module.name;
     normalizer.arena = &currentModule->internalTypes;
@@ -1656,10 +1658,7 @@ void TypeChecker::prototype(const ScopePtr& scope, const AstStatTypeAlias& typea
             FreeType* ftv = getMutable<FreeType>(ty);
             LUAU_ASSERT(ftv);
             ftv->forwardedTypeAlias = true;
-            if (FFlag::LuauRetainDefinitionAliasLocations)
-                bindingsMap[name] = {std::move(generics), std::move(genericPacks), ty, typealias.location};
-            else
-                bindingsMap[name] = {std::move(generics), std::move(genericPacks), ty};
+            bindingsMap[name] = {std::move(generics), std::move(genericPacks), ty};
 
             scope->typeAliasLocations[name] = typealias.location;
             scope->typeAliasNameLocations[name] = typealias.nameLocation;
@@ -1704,10 +1703,7 @@ void TypeChecker::prototype(const ScopePtr& scope, const AstStatDeclareClass& de
     TypeId metaTy = addType(TableType{TableState::Sealed, scope->level});
 
     ctv->metatable = metaTy;
-    if (FFlag::LuauRetainDefinitionAliasLocations)
-        scope->exportedTypeBindings[className] = TypeFun{{}, classTy, declaredClass.location};
-    else
-        scope->exportedTypeBindings[className] = TypeFun{{}, classTy};
+    scope->exportedTypeBindings[className] = TypeFun{{}, classTy};
 }
 
 ControlFlow TypeChecker::check(const ScopePtr& scope, const AstStatDeclareClass& declaredClass)
@@ -5725,10 +5721,6 @@ TypeId TypeChecker::resolveTypeWorker(const ScopePtr& scope, const AstType& anno
         TypeId ty = checkExpr(scope, *typeOf->expr).type;
         return ty;
     }
-    else if (annotation.is<AstTypeOptional>())
-    {
-        return builtinTypes->nilType;
-    }
     else if (const auto& un = annotation.as<AstTypeUnion>())
     {
         if (FFlag::LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)

Analysis/src/TypePath.cpp

@@ -14,8 +14,7 @@
 #include <type_traits>
 
 LUAU_FASTFLAG(LuauSolverV2);
-LUAU_FASTFLAGVARIABLE(LuauDisableNewSolverAssertsInMixedMode)
-
+LUAU_FASTFLAGVARIABLE(LuauDisableNewSolverAssertsInMixedMode);
 // Maximum number of steps to follow when traversing a path. May not always
 // equate to the number of components in a path, depending on the traversal
 // logic.
@@ -639,247 +638,6 @@ std::string toString(const TypePath::Path& path, bool prefixDot)
     return result.str();
 }
 
-std::string toStringHuman(const TypePath::Path& path)
-{
-    LUAU_ASSERT(FFlag::LuauSolverV2);
-
-    enum class State
-    {
-        Initial,
-        Normal,
-        Property,
-        PendingIs,
-        PendingAs,
-        PendingWhich,
-    };
-
-    std::stringstream result;
-    State state = State::Initial;
-    bool last = false;
-
-    auto strComponent = [&](auto&& c)
-    {
-        using T = std::decay_t<decltype(c)>;
-        if constexpr (std::is_same_v<T, TypePath::Property>)
-        {
-            if (state == State::PendingIs)
-                result << ", ";
-
-            switch (state)
-            {
-            case State::Initial:
-            case State::PendingIs:
-                if (c.isRead)
-                    result << "accessing `";
-                else
-                    result << "writing to `";
-                break;
-            case State::Property:
-                // if the previous state was a property, then we're doing a sequence of indexing
-                result << '.';
-                break;
-            default:
-                break;
-            }
-
-            result << c.name;
-
-            state = State::Property;
-        }
-        else if constexpr (std::is_same_v<T, TypePath::Index>)
-        {
-            size_t humanIndex = c.index + 1;
-
-            if (state == State::Initial && !last)
-                result << "in" << ' ';
-            else if (state == State::PendingIs)
-                result << ' ' << "has" << ' ';
-            else if (state == State::Property)
-                result << '`' << ' ' << "has" << ' ';
-
-            result << "the " << humanIndex;
-            switch (humanIndex)
-            {
-            case 1:
-                result << "st";
-                break;
-            case 2:
-                result << "nd";
-                break;
-            case 3:
-                result << "rd";
-                break;
-            default:
-                result << "th";
-            }
-
-            switch (c.variant)
-            {
-            case TypePath::Index::Variant::Pack:
-                result << ' ' << "entry in the type pack";
-                break;
-            case TypePath::Index::Variant::Union:
-                result << ' ' << "component of the union";
-                break;
-            case TypePath::Index::Variant::Intersection:
-                result << ' ' << "component of the intersection";
-                break;
-            }
-
-            if (state == State::PendingWhich)
-                result << ' ' << "which";
-
-            if (state == State::PendingIs || state == State::Property)
-                state = State::PendingAs;
-            else
-                state = State::PendingIs;
-        }
-        else if constexpr (std::is_same_v<T, TypePath::TypeField>)
-        {
-            if (state == State::Initial && !last)
-                result << "in" << ' ';
-            else if (state == State::PendingIs)
-                result << ", ";
-            else if (state == State::Property)
-                result << '`' << ' ' << "has" << ' ';
-
-            switch (c)
-            {
-            case TypePath::TypeField::Table:
-                result << "the table portion";
-                if (state == State::Property)
-                    state = State::PendingAs;
-                else
-                    state = State::PendingIs;
-                break;
-            case TypePath::TypeField::Metatable:
-                result << "the metatable portion";
-                if (state == State::Property)
-                    state = State::PendingAs;
-                else
-                    state = State::PendingIs;
-                break;
-            case TypePath::TypeField::LowerBound:
-                result << "the lower bound of" << ' ';
-                state = State::Normal;
-                break;
-            case TypePath::TypeField::UpperBound:
-                result << "the upper bound of" << ' ';
-                state = State::Normal;
-                break;
-            case TypePath::TypeField::IndexLookup:
-                result << "the index type";
-                if (state == State::Property)
-                    state = State::PendingAs;
-                else
-                    state = State::PendingIs;
-                break;
-            case TypePath::TypeField::IndexResult:
-                result << "the result of indexing";
-                if (state == State::Property)
-                    state = State::PendingAs;
-                else
-                    state = State::PendingIs;
-                break;
-            case TypePath::TypeField::Negated:
-                result << "the negation" << ' ';
-                state = State::Normal;
-                break;
-            case TypePath::TypeField::Variadic:
-                result << "the variadic" << ' ';
-                state = State::Normal;
-                break;
-            }
-        }
-        else if constexpr (std::is_same_v<T, TypePath::PackField>)
-        {
-            if (state == State::PendingIs)
-                result << ", ";
-            else if (state == State::Property)
-                result << "`, ";
-
-            switch (c)
-            {
-            case TypePath::PackField::Arguments:
-                if (state == State::Initial)
-                    result << "it" << ' ';
-                else if (state == State::PendingIs)
-                    result << "the function" << ' ';
-
-                result << "takes";
-                break;
-            case TypePath::PackField::Returns:
-                if (state == State::Initial)
-                    result << "it" << ' ';
-                else if (state == State::PendingIs)
-                    result << "the function" << ' ';
-
-                result << "returns";
-                break;
-            case TypePath::PackField::Tail:
-                if (state == State::Initial)
-                    result << "it has" << ' ';
-                result << "a tail of";
-                break;
-            }
-
-            if (state == State::PendingIs)
-            {
-                result << ' ';
-                state = State::PendingWhich;
-            }
-            else
-            {
-                result << ' ';
-                state = State::Normal;
-            }
-        }
-        else if constexpr (std::is_same_v<T, TypePath::Reduction>)
-        {
-            if (state == State::Initial)
-                result << "it" << ' ';
-            result << "reduces to" << ' ';
-            state = State::Normal;
-        }
-        else
-        {
-            static_assert(always_false_v<T>, "Unhandled Component variant");
-        }
-    };
-
-    size_t count = 0;
-
-    for (const TypePath::Component& component : path.components)
-    {
-        count++;
-        if (count == path.components.size())
-            last = true;
-
-        Luau::visit(strComponent, component);
-    }
-
-    switch (state)
-    {
-    case State::Property:
-        result << "` results in ";
-        break;
-    case State::PendingWhich:
-        // pending `which` becomes `is` if it's at the end
-        result << "is" << ' ';
-        break;
-    case State::PendingIs:
-        result << ' ' << "is" << ' ';
-        break;
-    case State::PendingAs:
-        result << ' ' << "as" << ' ';
-        break;
-    default:
-        break;
-    }
-
-    return result.str();
-}
-
 static bool traverse(TraversalState& state, const Path& path)
 {
     auto step = [&state](auto&& c)

Analysis/src/Unifier2.cpp

@@ -433,6 +433,9 @@ bool Unifier2::unify(TableType* subTable, const TableType* superTable)
         superTypePackParamsIter++;
     }
 
+    if (subTable->selfTy && superTable->selfTy)
+        result &= unify(*subTable->selfTy, *superTable->selfTy);
+
     if (subTable->indexer && superTable->indexer)
     {
         result &= unify(subTable->indexer->indexType, superTable->indexer->indexType);
@@ -647,33 +650,38 @@ struct FreeTypeSearcher : TypeVisitor
     {
     }
 
-    Polarity polarity = Polarity::Positive;
+    enum Polarity
+    {
+        Positive,
+        Negative,
+        Both,
+    };
+
+    Polarity polarity = Positive;
 
     void flip()
     {
         switch (polarity)
         {
-        case Polarity::Positive:
-            polarity = Polarity::Negative;
+        case Positive:
+            polarity = Negative;
             break;
-        case Polarity::Negative:
-            polarity = Polarity::Positive;
+        case Negative:
+            polarity = Positive;
             break;
-        case Polarity::Mixed:
+        case Both:
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
     }
 
     DenseHashSet<const void*> seenPositive{nullptr};
     DenseHashSet<const void*> seenNegative{nullptr};
 
-    bool seenWithCurrentPolarity(const void* ty)
+    bool seenWithPolarity(const void* ty)
     {
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
         {
             if (seenPositive.contains(ty))
                 return true;
@@ -681,7 +689,7 @@ struct FreeTypeSearcher : TypeVisitor
             seenPositive.insert(ty);
             return false;
         }
-        case Polarity::Negative:
+        case Negative:
         {
             if (seenNegative.contains(ty))
                 return true;
@@ -689,7 +697,7 @@ struct FreeTypeSearcher : TypeVisitor
             seenNegative.insert(ty);
             return false;
         }
-        case Polarity::Mixed:
+        case Both:
         {
             if (seenPositive.contains(ty) && seenNegative.contains(ty))
                 return true;
@@ -698,8 +706,6 @@ struct FreeTypeSearcher : TypeVisitor
             seenNegative.insert(ty);
             return false;
         }
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return false;
@@ -713,7 +719,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty) override
     {
-        if (seenWithCurrentPolarity(ty))
+        if (seenWithPolarity(ty))
             return false;
 
         LUAU_ASSERT(ty);
@@ -722,7 +728,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const FreeType& ft) override
     {
-        if (seenWithCurrentPolarity(ty))
+        if (seenWithPolarity(ty))
             return false;
 
         if (!subsumes(scope, ft.scope))
@@ -730,18 +736,16 @@ struct FreeTypeSearcher : TypeVisitor
 
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
             positiveTypes[ty]++;
             break;
-        case Polarity::Negative:
+        case Negative:
             negativeTypes[ty]++;
             break;
-        case Polarity::Mixed:
+        case Both:
             positiveTypes[ty]++;
             negativeTypes[ty]++;
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return true;
@@ -749,25 +753,23 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const TableType& tt) override
     {
-        if (seenWithCurrentPolarity(ty))
+        if (seenWithPolarity(ty))
             return false;
 
         if ((tt.state == TableState::Free || tt.state == TableState::Unsealed) && subsumes(scope, tt.scope))
         {
             switch (polarity)
             {
-            case Polarity::Positive:
+            case Positive:
                 positiveTypes[ty]++;
                 break;
-            case Polarity::Negative:
+            case Negative:
                 negativeTypes[ty]++;
                 break;
-            case Polarity::Mixed:
+            case Both:
                 positiveTypes[ty]++;
                 negativeTypes[ty]++;
                 break;
-            default:
-                LUAU_ASSERT(!"Unreachable");
             }
         }
 
@@ -780,7 +782,7 @@ struct FreeTypeSearcher : TypeVisitor
                 LUAU_ASSERT(prop.isShared());
 
                 Polarity p = polarity;
-                polarity = Polarity::Mixed;
+                polarity = Both;
                 traverse(prop.type());
                 polarity = p;
             }
@@ -797,7 +799,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const FunctionType& ft) override
     {
-        if (seenWithCurrentPolarity(ty))
+        if (seenWithPolarity(ty))
             return false;
 
         flip();
@@ -816,7 +818,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypePackId tp, const FreeTypePack& ftp) override
     {
-        if (seenWithCurrentPolarity(tp))
+        if (seenWithPolarity(tp))
             return false;
 
         if (!subsumes(scope, ftp.scope))
@@ -824,18 +826,16 @@ struct FreeTypeSearcher : TypeVisitor
 
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
             positiveTypes[tp]++;
             break;
-        case Polarity::Negative:
+        case Negative:
             negativeTypes[tp]++;
             break;
-        case Polarity::Mixed:
+        case Both:
             positiveTypes[tp]++;
             negativeTypes[tp]++;
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return true;

Ast/include/Luau/Ast.h

@@ -194,7 +194,6 @@ public:
     {
         Checked,
         Native,
-        Deprecated,
     };
 
     AstAttr(const Location& location, Type type);
@@ -454,7 +453,6 @@ public:
     void visit(AstVisitor* visitor) override;
 
     bool hasNativeAttribute() const;
-    bool hasAttribute(AstAttr::Type attributeType) const;
 
     AstArray<AstAttr*> attributes;
     AstArray<AstGenericType*> generics;
@@ -892,22 +890,14 @@ class AstStatTypeFunction : public AstStat
 public:
     LUAU_RTTI(AstStatTypeFunction);
 
-    AstStatTypeFunction(
-        const Location& location,
-        const AstName& name,
-        const Location& nameLocation,
-        AstExprFunction* body,
-        bool exported,
-        bool hasErrors
-    );
+    AstStatTypeFunction(const Location& location, const AstName& name, const Location& nameLocation, AstExprFunction* body, bool exported);
 
     void visit(AstVisitor* visitor) override;
 
     AstName name;
     Location nameLocation;
-    AstExprFunction* body = nullptr;
-    bool exported = false;
-    bool hasErrors = false;
+    AstExprFunction* body;
+    bool exported;
 };
 
 class AstStatDeclareGlobal : public AstStat
@@ -960,7 +950,6 @@ public:
     void visit(AstVisitor* visitor) override;
 
     bool isCheckedFunction() const;
-    bool hasAttribute(AstAttr::Type attributeType) const;
 
     AstArray<AstAttr*> attributes;
     AstName name;
@@ -1117,7 +1106,6 @@ public:
     void visit(AstVisitor* visitor) override;
 
     bool isCheckedFunction() const;
-    bool hasAttribute(AstAttr::Type attributeType) const;
 
     AstArray<AstAttr*> attributes;
     AstArray<AstGenericType*> generics;
@@ -1139,16 +1127,6 @@ public:
     AstExpr* expr;
 };
 
-class AstTypeOptional : public AstType
-{
-public:
-    LUAU_RTTI(AstTypeOptional)
-
-    AstTypeOptional(const Location& location);
-
-    void visit(AstVisitor* visitor) override;
-};
-
 class AstTypeUnion : public AstType
 {
 public:
@@ -1471,10 +1449,6 @@ public:
     {
         return visit(static_cast<AstStat*>(node));
     }
-    virtual bool visit(class AstStatTypeFunction* node)
-    {
-        return visit(static_cast<AstStat*>(node));
-    }
     virtual bool visit(class AstStatDeclareFunction* node)
     {
         return visit(static_cast<AstStat*>(node));
@@ -1514,10 +1488,6 @@ public:
     {
         return visit(static_cast<AstType*>(node));
     }
-    virtual bool visit(class AstTypeOptional* node)
-    {
-        return visit(static_cast<AstType*>(node));
-    }
     virtual bool visit(class AstTypeUnion* node)
     {
         return visit(static_cast<AstType*>(node));

Ast/include/Luau/Cst.h

@@ -105,21 +105,6 @@ public:
     Position closeBracketPosition;
 };
 
-class CstExprFunction : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstExprFunction)
-
-    CstExprFunction();
-
-    Position functionKeywordPosition{0, 0};
-    Position openGenericsPosition{0,0};
-    AstArray<Position> genericsCommaPositions;
-    Position closeGenericsPosition{0,0};
-    AstArray<Position> argsCommaPositions;
-    Position returnSpecifierPosition{0,0};
-};
-
 class CstExprTable : public CstNode
 {
 public:
@@ -275,24 +260,13 @@ public:
     Position opPosition;
 };
 
-class CstStatFunction : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstStatFunction)
-
-    explicit CstStatFunction(Position functionKeywordPosition);
-
-    Position functionKeywordPosition;
-};
-
 class CstStatLocalFunction : public CstNode
 {
 public:
     LUAU_CST_RTTI(CstStatLocalFunction)
 
-    explicit CstStatLocalFunction(Position localKeywordPosition, Position functionKeywordPosition);
+    explicit CstStatLocalFunction(Position functionKeywordPosition);
 
-    Position localKeywordPosition;
     Position functionKeywordPosition;
 };
 
@@ -337,17 +311,6 @@ public:
     Position equalsPosition;
 };
 
-class CstStatTypeFunction : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstStatTypeFunction)
-
-    CstStatTypeFunction(Position typeKeywordPosition, Position functionKeywordPosition);
-
-    Position typeKeywordPosition;
-    Position functionKeywordPosition;
-};
-
 class CstTypeReference : public CstNode
 {
 public:
@@ -396,32 +359,6 @@ public:
     bool isArray = false;
 };
 
-class CstTypeFunction : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypeFunction)
-
-    CstTypeFunction(
-        Position openGenericsPosition,
-        AstArray<Position> genericsCommaPositions,
-        Position closeGenericsPosition,
-        Position openArgsPosition,
-        AstArray<std::optional<Position>> argumentNameColonPositions,
-        AstArray<Position> argumentsCommaPositions,
-        Position closeArgsPosition,
-        Position returnArrowPosition
-    );
-
-    Position openGenericsPosition;
-    AstArray<Position> genericsCommaPositions;
-    Position closeGenericsPosition;
-    Position openArgsPosition;
-    AstArray<std::optional<Position>> argumentNameColonPositions;
-    AstArray<Position> argumentsCommaPositions;
-    Position closeArgsPosition;
-    Position returnArrowPosition;
-};
-
 class CstTypeTypeof : public CstNode
 {
 public:
@@ -433,28 +370,6 @@ public:
     Position closePosition;
 };
 
-class CstTypeUnion : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypeUnion)
-
-    CstTypeUnion(std::optional<Position> leadingPosition, AstArray<Position> separatorPositions);
-
-    std::optional<Position> leadingPosition;
-    AstArray<Position> separatorPositions;
-};
-
-class CstTypeIntersection : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypeIntersection)
-
-    explicit CstTypeIntersection(std::optional<Position> leadingPosition, AstArray<Position> separatorPositions);
-
-    std::optional<Position> leadingPosition;
-    AstArray<Position> separatorPositions;
-};
-
 class CstTypeSingletonString : public CstNode
 {
 public:
@@ -467,26 +382,4 @@ public:
     unsigned int blockDepth;
 };
 
-class CstTypePackExplicit : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypePackExplicit)
-
-    CstTypePackExplicit(Position openParenthesesPosition, Position closeParenthesesPosition, AstArray<Position> commaPositions);
-
-    Position openParenthesesPosition;
-    Position closeParenthesesPosition;
-    AstArray<Position> commaPositions;
-};
-
-class CstTypePackGeneric : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypePackGeneric)
-
-    explicit CstTypePackGeneric(Position ellipsisPosition);
-
-    Position ellipsisPosition;
-};
-
 } // namespace Luau

Ast/include/Luau/Parser.h

@@ -125,7 +125,7 @@ private:
     AstStat* parseFor();
 
     // funcname ::= Name {`.' Name} [`:' Name]
-    AstExpr* parseFunctionName(bool& hasself, AstName& debugname);
+    AstExpr* parseFunctionName(Location start_DEPRECATED, bool& hasself, AstName& debugname);
 
     // function funcname funcbody
     LUAU_FORCEINLINE AstStat* parseFunctionStat(const AstArray<AstAttr*>& attributes = {nullptr, 0});
@@ -155,11 +155,9 @@ private:
     AstStat* parseTypeAlias(const Location& start, bool exported, Position typeKeywordPosition);
 
     // type function Name ... end
-    AstStat* parseTypeFunction(const Location& start, bool exported, Position typeKeywordPosition);
-
-    AstDeclaredClassProp parseDeclaredClassMethod(const AstArray<AstAttr*>& attributes);
-    AstDeclaredClassProp parseDeclaredClassMethod_DEPRECATED();
+    AstStat* parseTypeFunction(const Location& start, bool exported);
 
+    AstDeclaredClassProp parseDeclaredClassMethod();
 
     // `declare global' Name: Type |
     // `declare function' Name`(' [parlist] `)' [`:` Type]
@@ -194,8 +192,7 @@ private:
     std::tuple<bool, Location, AstTypePack*> parseBindingList(
         TempVector<Binding>& result,
         bool allowDot3 = false,
-        AstArray<Position>* commaPositions = nullptr,
-        std::optional<Position> initialCommaPosition = std::nullopt
+        TempVector<Position>* commaPositions = nullptr
     );
 
     AstType* parseOptionalType();
@@ -212,14 +209,9 @@ private:
     //      |   `(' [TypeList] `)' `->` ReturnType
 
     // Returns the variadic annotation, if it exists.
-    AstTypePack* parseTypeList(
-        TempVector<AstType*>& result,
-        TempVector<std::optional<AstArgumentName>>& resultNames,
-        TempVector<Position>* commaPositions = nullptr,
-        TempVector<std::optional<Position>>* nameColonPositions = nullptr
-    );
+    AstTypePack* parseTypeList(TempVector<AstType*>& result, TempVector<std::optional<AstArgumentName>>& resultNames);
 
-    std::optional<AstTypeList> parseOptionalReturnType(Position* returnSpecifierPosition = nullptr);
+    std::optional<AstTypeList> parseOptionalReturnType();
     std::pair<Location, AstTypeList> parseReturnType();
 
     struct TableIndexerResult
@@ -230,9 +222,9 @@ private:
         Position colonPosition;
     };
 
-    TableIndexerResult parseTableIndexer(AstTableAccess access, std::optional<Location> accessLocation, Lexeme begin);
-    // Remove with FFlagLuauStoreCSTData2
-    AstTableIndexer* parseTableIndexer_DEPRECATED(AstTableAccess access, std::optional<Location> accessLocation, Lexeme begin);
+    TableIndexerResult parseTableIndexer(AstTableAccess access, std::optional<Location> accessLocation);
+    // Remove with FFlagLuauStoreCSTData
+    AstTableIndexer* parseTableIndexer_DEPRECATED(AstTableAccess access, std::optional<Location> accessLocation);
 
     AstTypeOrPack parseFunctionType(bool allowPack, const AstArray<AstAttr*>& attributes);
     AstType* parseFunctionTypeTail(
@@ -313,7 +305,7 @@ private:
     std::pair<AstArray<AstGenericType*>, AstArray<AstGenericTypePack*>> parseGenericTypeList(
         bool withDefaultValues,
         Position* openPosition = nullptr,
-        AstArray<Position>* commaPositions = nullptr,
+        TempVector<Position>* commaPositions = nullptr,
         Position* closePosition = nullptr
     );
 
@@ -499,7 +491,6 @@ private:
     std::vector<AstGenericTypePack*> scratchGenericTypePacks;
     std::vector<std::optional<AstArgumentName>> scratchOptArgName;
     std::vector<Position> scratchPosition;
-    std::vector<std::optional<Position>> scratchOptPosition;
     std::string scratchData;
 
     CstNodeMap cstNodeMap;

Ast/src/Ast.cpp

@@ -3,24 +3,9 @@
 
 #include "Luau/Common.h"
 
-LUAU_FASTFLAG(LuauDeprecatedAttribute);
-
 namespace Luau
 {
 
-static bool hasAttributeInArray(const AstArray<AstAttr*> attributes, AstAttr::Type attributeType)
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-    for (const auto attribute : attributes)
-    {
-        if (attribute->type == attributeType)
-            return true;
-    }
-
-    return false;
-}
-
 static void visitTypeList(AstVisitor* visitor, const AstTypeList& list)
 {
     for (AstType* ty : list.types)
@@ -292,13 +277,6 @@ bool AstExprFunction::hasNativeAttribute() const
     return false;
 }
 
-bool AstExprFunction::hasAttribute(const AstAttr::Type attributeType) const
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-    return hasAttributeInArray(attributes, attributeType);
-}
-
 AstExprTable::AstExprTable(const Location& location, const AstArray<Item>& items)
     : AstExpr(ClassIndex(), location)
     , items(items)
@@ -813,15 +791,13 @@ AstStatTypeFunction::AstStatTypeFunction(
     const AstName& name,
     const Location& nameLocation,
     AstExprFunction* body,
-    bool exported,
-    bool hasErrors
+    bool exported
 )
     : AstStat(ClassIndex(), location)
     , name(name)
     , nameLocation(nameLocation)
     , body(body)
     , exported(exported)
-    , hasErrors(hasErrors)
 {
 }
 
@@ -918,13 +894,6 @@ bool AstStatDeclareFunction::isCheckedFunction() const
     return false;
 }
 
-bool AstStatDeclareFunction::hasAttribute(AstAttr::Type attributeType) const
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-    return hasAttributeInArray(attributes, attributeType);
-}
-
 AstStatDeclareClass::AstStatDeclareClass(
     const Location& location,
     const AstName& name,
@@ -1088,13 +1057,6 @@ bool AstTypeFunction::isCheckedFunction() const
     return false;
 }
 
-bool AstTypeFunction::hasAttribute(AstAttr::Type attributeType) const
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-    return hasAttributeInArray(attributes, attributeType);
-}
-
 AstTypeTypeof::AstTypeTypeof(const Location& location, AstExpr* expr)
     : AstType(ClassIndex(), location)
     , expr(expr)
@@ -1107,16 +1069,6 @@ void AstTypeTypeof::visit(AstVisitor* visitor)
         expr->visit(visitor);
 }
 
-AstTypeOptional::AstTypeOptional(const Location& location)
-    : AstType(ClassIndex(), location)
-{
-}
-
-void AstTypeOptional::visit(AstVisitor* visitor)
-{
-    visitor->visit(this);
-}
-
 AstTypeUnion::AstTypeUnion(const Location& location, const AstArray<AstType*>& types)
     : AstType(ClassIndex(), location)
     , types(types)

Ast/src/Cst.cpp

@@ -38,10 +38,6 @@ CstExprIndexExpr::CstExprIndexExpr(Position openBracketPosition, Position closeB
 {
 }
 
-CstExprFunction::CstExprFunction() : CstNode(CstClassIndex())
-{
-}
-
 CstExprTable::CstExprTable(const AstArray<Item>& items)
     : CstNode(CstClassIndex())
     , items(items)
@@ -129,19 +125,12 @@ CstStatCompoundAssign::CstStatCompoundAssign(Position opPosition)
 {
 }
 
-CstStatFunction::CstStatFunction(Position functionKeywordPosition)
+CstStatLocalFunction::CstStatLocalFunction(Position functionKeywordPosition)
     : CstNode(CstClassIndex())
     , functionKeywordPosition(functionKeywordPosition)
 {
 }
 
-CstStatLocalFunction::CstStatLocalFunction(Position localKeywordPosition, Position functionKeywordPosition)
-    : CstNode(CstClassIndex())
-    , localKeywordPosition(localKeywordPosition)
-    , functionKeywordPosition(functionKeywordPosition)
-{
-}
-
 CstGenericType::CstGenericType(std::optional<Position> defaultEqualsPosition)
     : CstNode(CstClassIndex())
     , defaultEqualsPosition(defaultEqualsPosition)
@@ -171,13 +160,6 @@ CstStatTypeAlias::CstStatTypeAlias(
 {
 }
 
-CstStatTypeFunction::CstStatTypeFunction(Position typeKeywordPosition, Position functionKeywordPosition)
-    : CstNode(CstClassIndex())
-    , typeKeywordPosition(typeKeywordPosition)
-    , functionKeywordPosition(functionKeywordPosition)
-{
-}
-
 CstTypeReference::CstTypeReference(
     std::optional<Position> prefixPointPosition,
     Position openParametersPosition,
@@ -199,28 +181,6 @@ CstTypeTable::CstTypeTable(AstArray<Item> items, bool isArray)
 {
 }
 
-CstTypeFunction::CstTypeFunction(
-    Position openGenericsPosition,
-    AstArray<Position> genericsCommaPositions,
-    Position closeGenericsPosition,
-    Position openArgsPosition,
-    AstArray<std::optional<Position>> argumentNameColonPositions,
-    AstArray<Position> argumentsCommaPositions,
-    Position closeArgsPosition,
-    Position returnArrowPosition
-)
-    : CstNode(CstClassIndex())
-    , openGenericsPosition(openGenericsPosition)
-    , genericsCommaPositions(genericsCommaPositions)
-    , closeGenericsPosition(closeGenericsPosition)
-    , openArgsPosition(openArgsPosition)
-    , argumentNameColonPositions(argumentNameColonPositions)
-    , argumentsCommaPositions(argumentsCommaPositions)
-    , closeArgsPosition(closeArgsPosition)
-    , returnArrowPosition(returnArrowPosition)
-{
-}
-
 CstTypeTypeof::CstTypeTypeof(Position openPosition, Position closePosition)
     : CstNode(CstClassIndex())
     , openPosition(openPosition)
@@ -228,20 +188,6 @@ CstTypeTypeof::CstTypeTypeof(Position openPosition, Position closePosition)
 {
 }
 
-CstTypeUnion::CstTypeUnion(std::optional<Position> leadingPosition, AstArray<Position> separatorPositions)
-    : CstNode(CstClassIndex())
-    , leadingPosition(leadingPosition)
-    , separatorPositions(separatorPositions)
-{
-}
-
-CstTypeIntersection::CstTypeIntersection(std::optional<Position> leadingPosition, AstArray<Position> separatorPositions)
-    : CstNode(CstClassIndex())
-    , leadingPosition(leadingPosition)
-    , separatorPositions(separatorPositions)
-{
-}
-
 CstTypeSingletonString::CstTypeSingletonString(AstArray<char> sourceString, CstExprConstantString::QuoteStyle quoteStyle, unsigned int blockDepth)
     : CstNode(CstClassIndex())
     , sourceString(sourceString)
@@ -251,18 +197,4 @@ CstTypeSingletonString::CstTypeSingletonString(AstArray<char> sourceString, CstE
     LUAU_ASSERT(quoteStyle != CstExprConstantString::QuotedInterp);
 }
 
-CstTypePackExplicit::CstTypePackExplicit(Position openParenthesesPosition, Position closeParenthesesPosition, AstArray<Position> commaPositions)
-    : CstNode(CstClassIndex())
-    , openParenthesesPosition(openParenthesesPosition)
-    , closeParenthesesPosition(closeParenthesesPosition)
-    , commaPositions(commaPositions)
-{
-}
-
-CstTypePackGeneric::CstTypePackGeneric(Position ellipsisPosition)
-    : CstNode(CstClassIndex())
-    , ellipsisPosition(ellipsisPosition)
-{
-}
-
 } // namespace Luau

Ast/src/Lexer.cpp

@@ -8,6 +8,8 @@
 
 #include <limits.h>
 
+LUAU_FASTFLAGVARIABLE(LexerFixInterpStringStart)
+
 namespace Luau
 {
 
@@ -787,7 +789,7 @@ Lexeme Lexer::readNext()
             return Lexeme(Location(start, 1), '}');
         }
 
-        return readInterpolatedStringSection(start, Lexeme::InterpStringMid, Lexeme::InterpStringEnd);
+        return readInterpolatedStringSection(FFlag::LexerFixInterpStringStart ? start : position(), Lexeme::InterpStringMid, Lexeme::InterpStringEnd);
     }
 
     case '=':

CMakeLists.txt

@@ -4,7 +4,7 @@ if(EXT_PLATFORM_STRING)
     return()
 endif()
 
-cmake_minimum_required(VERSION 3.10)
+cmake_minimum_required(VERSION 3.0)
 
 option(LUAU_BUILD_CLI "Build CLI" ON)
 option(LUAU_BUILD_TESTS "Build tests" ON)

Compiler/src/Types.cpp

@@ -125,10 +125,6 @@ static LuauBytecodeType getType(
     {
         return getType(group->type, generics, typeAliases, resolveAliases, hostVectorType, userdataTypes, bytecode);
     }
-    else if (const AstTypeOptional* optional = ty->as<AstTypeOptional>())
-    {
-        return LBC_TYPE_NIL;
-    }
 
     return LBC_TYPE_ANY;
 }

Sources.cmake

@@ -169,6 +169,7 @@ target_sources(Luau.CodeGen PRIVATE
 # Luau.Analysis Sources
 target_sources(Luau.Analysis PRIVATE
     Analysis/include/Luau/Anyification.h
+    Analysis/include/Luau/AnyTypeSummary.h
     Analysis/include/Luau/ApplyTypeFunction.h
     Analysis/include/Luau/AstJsonEncoder.h
     Analysis/include/Luau/AstQuery.h
@@ -247,6 +248,7 @@ target_sources(Luau.Analysis PRIVATE
     Analysis/include/Luau/VisitType.h
 
     Analysis/src/Anyification.cpp
+    Analysis/src/AnyTypeSummary.cpp
     Analysis/src/ApplyTypeFunction.cpp
     Analysis/src/AstJsonEncoder.cpp
     Analysis/src/AstQuery.cpp
@@ -431,6 +433,7 @@ endif()
 if(TARGET Luau.UnitTest)
     # Luau.UnitTest Sources
     target_sources(Luau.UnitTest PRIVATE
+        tests/AnyTypeSummary.test.cpp
         tests/AssemblyBuilderA64.test.cpp
         tests/AssemblyBuilderX64.test.cpp
         tests/AstJsonEncoder.test.cpp

VM/src/lgc.cpp

@@ -443,7 +443,7 @@ static void shrinkstack(lua_State* L)
 
     if (3 * size_t(s_used) < size_t(L->stacksize) && 2 * (BASIC_STACK_SIZE + EXTRA_STACK) < L->stacksize)
         luaD_reallocstack(L, L->stacksize / 2, 0); // still big enough...
-    condhardstacktests(luaD_reallocstack(L, s_used, 0));
+    condhardstacktests(luaD_reallocstack(L, s_used));
 }
 
 /*

VM/src/lgc.h

@@ -76,7 +76,7 @@
 
 #define luaC_checkGC(L) \
     { \
-        condhardstacktests(luaD_reallocstack(L, L->stacksize - EXTRA_STACK, 0)); \
+        condhardstacktests(luaD_reallocstack(L, L->stacksize - EXTRA_STACK)); \
         if (luaC_needsGC(L)) \
         { \
             condhardmemtests(luaC_validate(L), 1); \

fuzz/proto.cpp

@@ -134,7 +134,6 @@ int registerTypes(Luau::Frontend& frontend, Luau::GlobalTypes& globals, bool for
     getMutable<TableType>(vector3MetaType)->props = {
         {"__add", {makeFunction(arena, nullopt, {vector3InstanceType, vector3InstanceType}, {vector3InstanceType})}},
     };
-    getMutable<TableType>(vector3MetaType)->state = TableState::Sealed;
 
     globals.globalScope->exportedTypeBindings["Vector3"] = TypeFun{{}, vector3InstanceType};
 

tests/AstJsonEncoder.test.cpp

@@ -12,7 +12,6 @@
 using namespace Luau;
 
 LUAU_FASTFLAG(LuauAstTypeGroup3)
-LUAU_FASTFLAG(LuauFixFunctionWithAttributesStartLocation)
 
 struct JsonEncoderFixture
 {
@@ -441,9 +440,7 @@ TEST_CASE_FIXTURE(JsonEncoderFixture, "encode_AstAttr")
     AstStat* expr = expectParseStatement("@checked function a(b) return c end");
 
     std::string_view expected =
-        FFlag::LuauFixFunctionWithAttributesStartLocation
-            ? R"({"type":"AstStatFunction","location":"0,0 - 0,35","name":{"type":"AstExprGlobal","location":"0,18 - 0,19","global":"a"},"func":{"type":"AstExprFunction","location":"0,0 - 0,35","attributes":[{"type":"AstAttr","location":"0,0 - 0,8","name":"checked"}],"generics":[],"genericPacks":[],"args":[{"luauType":null,"name":"b","type":"AstLocal","location":"0,20 - 0,21"}],"vararg":false,"varargLocation":"0,0 - 0,0","body":{"type":"AstStatBlock","location":"0,22 - 0,32","hasEnd":true,"body":[{"type":"AstStatReturn","location":"0,23 - 0,31","list":[{"type":"AstExprGlobal","location":"0,30 - 0,31","global":"c"}]}]},"functionDepth":1,"debugname":"a"}})"
-            : R"({"type":"AstStatFunction","location":"0,9 - 0,35","name":{"type":"AstExprGlobal","location":"0,18 - 0,19","global":"a"},"func":{"type":"AstExprFunction","location":"0,9 - 0,35","attributes":[{"type":"AstAttr","location":"0,0 - 0,8","name":"checked"}],"generics":[],"genericPacks":[],"args":[{"luauType":null,"name":"b","type":"AstLocal","location":"0,20 - 0,21"}],"vararg":false,"varargLocation":"0,0 - 0,0","body":{"type":"AstStatBlock","location":"0,22 - 0,32","hasEnd":true,"body":[{"type":"AstStatReturn","location":"0,23 - 0,31","list":[{"type":"AstExprGlobal","location":"0,30 - 0,31","global":"c"}]}]},"functionDepth":1,"debugname":"a"}})";
+        R"({"type":"AstStatFunction","location":"0,9 - 0,35","name":{"type":"AstExprGlobal","location":"0,18 - 0,19","global":"a"},"func":{"type":"AstExprFunction","location":"0,9 - 0,35","attributes":[{"type":"AstAttr","location":"0,0 - 0,8","name":"checked"}],"generics":[],"genericPacks":[],"args":[{"luauType":null,"name":"b","type":"AstLocal","location":"0,20 - 0,21"}],"vararg":false,"varargLocation":"0,0 - 0,0","body":{"type":"AstStatBlock","location":"0,22 - 0,32","hasEnd":true,"body":[{"type":"AstStatReturn","location":"0,23 - 0,31","list":[{"type":"AstExprGlobal","location":"0,30 - 0,31","global":"c"}]}]},"functionDepth":1,"debugname":"a"}})";
 
     CHECK(toJson(expr) == expected);
 }

tests/Autocomplete.test.cpp

@@ -7,8 +7,6 @@
 #include "Luau/VisitType.h"
 #include "Luau/StringUtils.h"
 
-
-#include "ClassFixture.h"
 #include "Fixture.h"
 #include "ScopedFlags.h"
 
@@ -21,9 +19,6 @@ LUAU_FASTFLAG(LuauSetMetatableDoesNotTimeTravel)
 LUAU_FASTINT(LuauTypeInferRecursionLimit)
 
 LUAU_FASTFLAG(LuauExposeRequireByStringAutocomplete)
-LUAU_FASTFLAG(LuauAutocompleteUnionCopyPreviousSeen)
-LUAU_FASTFLAG(LuauUserTypeFunTypecheck)
-LUAU_FASTFLAG(LuauTypeFunResultInAutocomplete)
 
 using namespace Luau;
 
@@ -159,10 +154,6 @@ struct ACBuiltinsFixture : ACFixtureImpl<BuiltinsFixture>
 {
 };
 
-struct ACClassFixture : ACFixtureImpl<ClassFixture>
-{
-};
-
 TEST_SUITE_BEGIN("AutocompleteTest");
 
 TEST_CASE_FIXTURE(ACFixture, "empty_program")
@@ -4425,99 +4416,4 @@ local x = 1 + result.
     CHECK(ac.entryMap.count("x"));
 }
 
-TEST_CASE_FIXTURE(ACClassFixture, "ac_dont_overflow_on_recursive_union")
-{
-    ScopedFastFlag _{FFlag::LuauAutocompleteUnionCopyPreviousSeen, true};
-    check(R"(
-        local table1: {ChildClass} = {}
-        local table2 = {}
-
-        for index, value in table2[1] do
-            table.insert(table1, value)
-            value.@1
-        end
-    )");
-
-    auto ac = autocomplete('1');
-    // RIDE-11517: This should *really* be the members of `ChildClass`, but
-    // would previously stack overflow.
-    CHECK(ac.entryMap.empty());
-}
-
-TEST_CASE_FIXTURE(ACBuiltinsFixture, "type_function_has_types_definitions")
-{
-    // Needs new global initialization in the Fixture, but can't place the flag inside the base Fixture
-    if (!FFlag::LuauUserTypeFunTypecheck)
-        return;
-
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-
-    check(R"(
-type function foo()
-    types.@1
-end
-    )");
-
-    auto ac = autocomplete('1');
-    CHECK_EQ(ac.entryMap.count("singleton"), 1);
-}
-
-TEST_CASE_FIXTURE(ACBuiltinsFixture, "type_function_private_scope")
-{
-    // Needs new global initialization in the Fixture, but can't place the flag inside the base Fixture
-    if (!FFlag::LuauUserTypeFunTypecheck)
-        return;
-
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-
-    // Global scope polution by the embedder has no effect
-    addGlobalBinding(frontend.globals, "thisAlsoShouldNotBeThere", Binding{builtinTypes->anyType});
-    addGlobalBinding(frontend.globalsForAutocomplete, "thisAlsoShouldNotBeThere", Binding{builtinTypes->anyType});
-
-    check(R"(
-local function thisShouldNotBeThere() end
-
-type function thisShouldBeThere() end
-
-type function foo()
-    this@1
-end
-
-this@2
-    )");
-
-    auto ac = autocomplete('1');
-    CHECK_EQ(ac.entryMap.count("thisShouldNotBeThere"), 0);
-    CHECK_EQ(ac.entryMap.count("thisAlsoShouldNotBeThere"), 0);
-    CHECK_EQ(ac.entryMap.count("thisShouldBeThere"), 1);
-
-    ac = autocomplete('2');
-    CHECK_EQ(ac.entryMap.count("thisShouldNotBeThere"), 1);
-    CHECK_EQ(ac.entryMap.count("thisAlsoShouldNotBeThere"), 1);
-    CHECK_EQ(ac.entryMap.count("thisShouldBeThere"), 0);
-}
-
-TEST_CASE_FIXTURE(ACBuiltinsFixture, "type_function_eval_in_autocomplete")
-{
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-    ScopedFastFlag luauTypeFunResultInAutocomplete{FFlag::LuauTypeFunResultInAutocomplete, true};
-
-    check(R"(
-type function foo(x)
-    local tbl = types.newtable(nil, nil, nil)
-    tbl:setproperty(types.singleton("boolean"), x)
-    tbl:setproperty(types.singleton("number"), types.number)
-    return tbl
-end
-
-local function test(a: foo<string>)
-    return a.@1
-end
-    )");
-
-    auto ac = autocomplete('1');
-    CHECK_EQ(ac.entryMap.count("boolean"), 1);
-    CHECK_EQ(ac.entryMap.count("number"), 1);
-}
-
 TEST_SUITE_END();

tests/ClassFixture.cpp

@@ -9,8 +9,7 @@ using std::nullopt;
 namespace Luau
 {
 
-ClassFixture::ClassFixture(bool prepareAutocomplete)
-    : BuiltinsFixture(prepareAutocomplete)
+ClassFixture::ClassFixture()
 {
     GlobalTypes& globals = frontend.globals;
     TypeArena& arena = globals.globalTypes;

tests/ClassFixture.h

@@ -8,7 +8,7 @@ namespace Luau
 
 struct ClassFixture : BuiltinsFixture
 {
-    explicit ClassFixture(bool prepareAutocomplete = false);
+    ClassFixture();
 
     TypeId vector2Type;
     TypeId vector2InstanceType;

tests/ConstraintGeneratorFixture.cpp

@@ -34,7 +34,6 @@ void ConstraintGeneratorFixture::generateConstraints(const std::string& code)
         builtinTypes,
         NotNull(&ice),
         frontend.globals.globalScope,
-        frontend.globals.globalTypeFunctionScope,
         /*prepareModuleScope*/ nullptr,
         &logger,
         NotNull{dfg.get()},

tests/Fixture.cpp

@@ -323,7 +323,6 @@ AstStatBlock* Fixture::parse(const std::string& source, const ParseOptions& pars
                     NotNull{&moduleResolver},
                     NotNull{&fileResolver},
                     frontend.globals.globalScope,
-                    frontend.globals.globalTypeFunctionScope,
                     /*prepareModuleScope*/ nullptr,
                     frontend.options,
                     {},
@@ -372,7 +371,7 @@ LintResult Fixture::lint(const std::string& source, const std::optional<LintOpti
     fileResolver.source[mm] = std::move(source);
     frontend.markDirty(mm);
 
-    return lintModule(mm, lintOptions);
+    return lintModule(mm);
 }
 
 LintResult Fixture::lintModule(const ModuleName& moduleName, const std::optional<LintOptions>& lintOptions)

tests/Frontend.test.cpp

@@ -17,7 +17,7 @@ LUAU_FASTFLAG(LuauSolverV2);
 LUAU_FASTFLAG(DebugLuauFreezeArena)
 LUAU_FASTFLAG(DebugLuauMagicTypes)
 LUAU_FASTFLAG(LuauSelectivelyRetainDFGArena)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
+LUAU_FASTFLAG(LuauModuleHoldsAstRoot)
 
 namespace
 {
@@ -920,17 +920,7 @@ TEST_CASE_FIXTURE(FrontendFixture, "it_should_be_safe_to_stringify_errors_when_f
     // When this test fails, it is because the TypeIds needed by the error have been deallocated.
     // It is thus basically impossible to predict what will happen when this assert is evaluated.
     // It could segfault, or you could see weird type names like the empty string or <VALUELESS BY EXCEPTION>
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        REQUIRE_EQ(
-            "Type\n\t"
-            "'{ count: string }'"
-            "\ncould not be converted into\n\t"
-            "'{ Count: number }'",
-            toString(result.errors[0])
-        );
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
         REQUIRE_EQ(
             R"(Type
     '{ count: string }'
@@ -1554,6 +1544,7 @@ TEST_CASE_FIXTURE(FrontendFixture, "check_module_references_allocator")
 
 TEST_CASE_FIXTURE(FrontendFixture, "check_module_references_correct_ast_root")
 {
+    ScopedFastFlag sff{FFlag::LuauModuleHoldsAstRoot, true};
     fileResolver.source["game/workspace/MyScript"] = R"(
         print("Hello World")
     )";
@@ -1791,96 +1782,4 @@ TEST_CASE_FIXTURE(FrontendFixture, "test_invalid_dependency_tracking_per_module_
     CHECK(frontend.allModuleDependenciesValid("game/Gui/Modules/A", opts.forAutocomplete));
 }
 
-TEST_CASE_FIXTURE(FrontendFixture, "queue_check_simple")
-{
-    fileResolver.source["game/Gui/Modules/A"] = R"(
-        --!strict
-        return {hello=5, world=true}
-    )";
-    fileResolver.source["game/Gui/Modules/B"] = R"(
-        --!strict
-        local Modules = game:GetService('Gui').Modules
-        local A = require(Modules.A)
-        return {b_value = A.hello}
-    )";
-
-    frontend.queueModuleCheck("game/Gui/Modules/B");
-    frontend.checkQueuedModules();
-
-    auto result = frontend.getCheckResult("game/Gui/Modules/B", true);
-    REQUIRE(result);
-    LUAU_REQUIRE_NO_ERRORS(*result);
-}
-
-TEST_CASE_FIXTURE(FrontendFixture, "queue_check_cycle_instant")
-{
-    fileResolver.source["game/Gui/Modules/A"] = R"(
-        --!strict
-        local Modules = game:GetService('Gui').Modules
-        local B = require(Modules.B)
-        return {a_value = B.hello}
-    )";
-    fileResolver.source["game/Gui/Modules/B"] = R"(
-        --!strict
-        local Modules = game:GetService('Gui').Modules
-        local A = require(Modules.A)
-        return {b_value = A.hello}
-    )";
-
-    frontend.queueModuleCheck("game/Gui/Modules/B");
-    frontend.checkQueuedModules();
-
-    auto result = frontend.getCheckResult("game/Gui/Modules/B", true);
-    REQUIRE(result);
-    LUAU_REQUIRE_ERROR_COUNT(2, *result);
-    CHECK(toString(result->errors[0]) == "Cyclic module dependency: game/Gui/Modules/B -> game/Gui/Modules/A");
-    CHECK(toString(result->errors[1]) == "Cyclic module dependency: game/Gui/Modules/A -> game/Gui/Modules/B");
-}
-
-TEST_CASE_FIXTURE(FrontendFixture, "queue_check_cycle_delayed")
-{
-    fileResolver.source["game/Gui/Modules/C"] = R"(
-        --!strict
-        return {c_value = 5}
-    )";
-    fileResolver.source["game/Gui/Modules/A"] = R"(
-        --!strict
-        local Modules = game:GetService('Gui').Modules
-        local C = require(Modules.C)
-        local B = require(Modules.B)
-        return {a_value = B.hello + C.c_value}
-    )";
-    fileResolver.source["game/Gui/Modules/B"] = R"(
-        --!strict
-        local Modules = game:GetService('Gui').Modules
-        local C = require(Modules.C)
-        local A = require(Modules.A)
-        return {b_value = A.hello + C.c_value}
-    )";
-
-    frontend.queueModuleCheck("game/Gui/Modules/B");
-    frontend.checkQueuedModules();
-
-    auto result = frontend.getCheckResult("game/Gui/Modules/B", true);
-    REQUIRE(result);
-    LUAU_REQUIRE_ERROR_COUNT(2, *result);
-    CHECK(toString(result->errors[0]) == "Cyclic module dependency: game/Gui/Modules/B -> game/Gui/Modules/A");
-    CHECK(toString(result->errors[1]) == "Cyclic module dependency: game/Gui/Modules/A -> game/Gui/Modules/B");
-}
-
-TEST_CASE_FIXTURE(FrontendFixture, "queue_check_propagates_ice")
-{
-    ScopedFastFlag sffs{FFlag::DebugLuauMagicTypes, true};
-
-    ModuleName mm = fromString("MainModule");
-    fileResolver.source[mm] = R"(
-        --!strict
-        local a: _luau_ice = 55
-    )";
-    frontend.markDirty(mm);
-    frontend.queueModuleCheck("MainModule");
-
-    CHECK_THROWS_AS(frontend.checkQueuedModules(), InternalCompilerError);
-}
-
 TEST_SUITE_END();

tests/Generalization.test.cpp

@@ -15,9 +15,6 @@
 using namespace Luau;
 
 LUAU_FASTFLAG(LuauSolverV2)
-LUAU_FASTFLAG(DebugLuauForbidInternalTypes)
-LUAU_FASTFLAG(LuauTrackInteriorFreeTypesOnScope)
-LUAU_FASTFLAG(LuauTrackInferredFunctionTypeFromCall)
 
 TEST_SUITE_BEGIN("Generalization");
 
@@ -253,42 +250,4 @@ end
 )");
 }
 
-TEST_CASE_FIXTURE(BuiltinsFixture, "generalization_should_not_leak_free_type")
-{
-    ScopedFastFlag sffs[] = {
-        {FFlag::DebugLuauForbidInternalTypes, true},
-        {FFlag::LuauTrackInteriorFreeTypesOnScope, true},
-        {FFlag::LuauTrackInferredFunctionTypeFromCall, true}
-    };
-
-    // This test case should just not assert
-    CheckResult result = check(R"(
-        function foo()
-
-            local productButtonPairs = {}
-            local func
-            local dir = -1
-
-            local function updateSearch()
-                for product, button in pairs(productButtonPairs) do
-                    -- This line may have a floating free type pack.
-                    button.LayoutOrder = func(product) * dir
-                end
-            end
-
-            function(mode)
-                if mode == 'New'then
-                    func = function(p)
-                        return p.id
-                    end
-                elseif mode == 'Price'then
-                    func = function(p)
-                        return p.price
-                    end
-                end
-            end
-        end
-    )");
-}
-
 TEST_SUITE_END();

tests/Lexer.test.cpp

@@ -8,6 +8,8 @@
 
 using namespace Luau;
 
+LUAU_FASTFLAG(LexerFixInterpStringStart)
+
 TEST_SUITE_BEGIN("LexerTests");
 
 TEST_CASE("broken_string_works")
@@ -154,7 +156,7 @@ TEST_CASE("string_interpolation_basic")
     Lexeme interpEnd = lexer.next();
     CHECK_EQ(interpEnd.type, Lexeme::InterpStringEnd);
     // The InterpStringEnd should start with }, not `.
-    CHECK_EQ(interpEnd.location.begin.column, 11);
+    CHECK_EQ(interpEnd.location.begin.column, FFlag::LexerFixInterpStringStart ? 11 : 12);
 }
 
 TEST_CASE("string_interpolation_full")
@@ -175,7 +177,7 @@ TEST_CASE("string_interpolation_full")
     Lexeme interpMid = lexer.next();
     CHECK_EQ(interpMid.type, Lexeme::InterpStringMid);
     CHECK_EQ(interpMid.toString(), "} {");
-    CHECK_EQ(interpMid.location.begin.column, 11);
+    CHECK_EQ(interpMid.location.begin.column, FFlag::LexerFixInterpStringStart ? 11 : 12);
 
     Lexeme quote2 = lexer.next();
     CHECK_EQ(quote2.type, Lexeme::QuotedString);
@@ -184,7 +186,7 @@ TEST_CASE("string_interpolation_full")
     Lexeme interpEnd = lexer.next();
     CHECK_EQ(interpEnd.type, Lexeme::InterpStringEnd);
     CHECK_EQ(interpEnd.toString(), "} end`");
-    CHECK_EQ(interpEnd.location.begin.column, 19);
+    CHECK_EQ(interpEnd.location.begin.column, FFlag::LexerFixInterpStringStart ? 19 : 20);
 }
 
 TEST_CASE("string_interpolation_double_brace")

tests/Linter.test.cpp

@@ -9,7 +9,6 @@
 
 LUAU_FASTFLAG(LuauSolverV2);
 LUAU_FASTFLAG(LintRedundantNativeAttribute);
-LUAU_FASTFLAG(LuauDeprecatedAttribute);
 
 using namespace Luau;
 
@@ -1601,326 +1600,6 @@ setfenv(h :: any, {})
     CHECK_EQ(result.warnings[3].location.begin.line + 1, 11);
 }
 
-static void checkDeprecatedWarning(const Luau::LintWarning& warning, const Luau::Position& begin, const Luau::Position& end, const char* msg)
-{
-    CHECK_EQ(warning.code, LintWarning::Code_DeprecatedApi);
-    CHECK_EQ(warning.location, Location(begin, end));
-    CHECK_EQ(warning.text, msg);
-}
-
-TEST_CASE_FIXTURE(Fixture, "DeprecatedAttribute")
-{
-    ScopedFastFlag sff[] = {{FFlag::LuauDeprecatedAttribute, true}, {FFlag::LuauSolverV2, true}};
-
-    // @deprecated works on local functions
-    {
-        LintResult result = lint(R"(
-@deprecated
-local function testfun(x)
-    return x + 1
-end
-
-testfun(1)
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(6, 0), Position(6, 7), "Function 'testfun' is deprecated");
-    }
-
-    // @deprecated works on globals functions
-    {
-        LintResult result = lint(R"(
-@deprecated
-function testfun(x)
-    return x + 1
-end
-
-testfun(1)
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(6, 0), Position(6, 7), "Function 'testfun' is deprecated");
-    }
-
-    // @deprecated works on fully typed functions
-    {
-        LintResult result = lint(R"(
-@deprecated
-local function testfun(x:number):number
-    return x + 1
-end
-
-if math.random(2) == 2 then
-    testfun(1)
-end
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(7, 4), Position(7, 11), "Function 'testfun' is deprecated");
-    }
-
-    // @deprecated works on functions without an explicit return type
-    {
-        LintResult result = lint(R"(
-@deprecated
-local function testfun(x:number)
-    return x + 1
-end
-
-g(testfun)
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(6, 2), Position(6, 9), "Function 'testfun' is deprecated");
-    }
-
-    // @deprecated works on functions without an explicit argument type
-    {
-        LintResult result = lint(R"(
-@deprecated
-local function testfun(x):number
-    if x == 1 then
-        return x
-    else
-        return 1 + testfun(x - 1)
-    end
-end
-
-testfun(1)
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(10, 0), Position(10, 7), "Function 'testfun' is deprecated");
-    }
-
-    // @deprecated works on inner functions
-    {
-        LintResult result = lint(R"(
-function flipFlop()
-    local state = false
-
-    @deprecated
-    local function invert()
-        state = !state
-        return state
-    end
-
-    return invert
-end
-
-f = flipFlop()
-assert(f() == true)
-)");
-
-        REQUIRE(2 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(10, 11), Position(10, 17), "Function 'invert' is deprecated");
-        checkDeprecatedWarning(result.warnings[1], Position(14, 7), Position(14, 8), "Function 'f' is deprecated");
-    }
-
-    // @deprecated does not automatically apply to inner functions
-    {
-        LintResult result = lint(R"(
-@deprecated
-function flipFlop()
-    local state = false
-
-    local function invert()
-        state = !state
-        return state
-    end
-
-    return invert
-end
-
-f = flipFlop()
-assert(f() == true)
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(13, 4), Position(13, 12), "Function 'flipFlop' is deprecated");
-    }
-
-    // @deprecated works correctly if deprecated function is shadowed
-    {
-        LintResult result = lint(R"(
-@deprecated
-local function doTheThing()
-    print("doing")
-end
-
-doTheThing()
-
-local function shadow()
-    local function doTheThing()
-        print("doing!")
-    end
-
-    doTheThing()
-end
-
-shadow()
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(6, 0), Position(6, 10), "Function 'doTheThing' is deprecated");
-    }
-
-    // @deprecated does not issue warnings if a deprecated function uses itself
-    {
-        LintResult result = lint(R"(
-@deprecated
-function fibonacci(n)
-    if n == 0 then
-        return 0
-    elseif n == 1 then
-        return 1
-    else
-        return fibonacci(n - 1) + fibonacci(n - 2)
-    end
-end
-
-fibonacci(5)
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(12, 0), Position(12, 9), "Function 'fibonacci' is deprecated");
-    }
-
-    // @deprecated works for mutually recursive functions
-    {
-        LintResult result = lint(R"(
-@deprecated
-function odd(x)
-    if x == 0 then
-        return false
-    else
-        return even(x - 1)
-    end
-end
-
-@deprecated
-function even(x)
-    if x == 0 then
-        return true
-    else
-        return odd(x - 1)
-    end
-end
-
-assert(odd(1) == true)
-assert(even(0) == true)
-)");
-
-        REQUIRE(4 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(6, 15), Position(6, 19), "Function 'even' is deprecated");
-        checkDeprecatedWarning(result.warnings[1], Position(15, 15), Position(15, 18), "Function 'odd' is deprecated");
-        checkDeprecatedWarning(result.warnings[2], Position(19, 7), Position(19, 10), "Function 'odd' is deprecated");
-        checkDeprecatedWarning(result.warnings[3], Position(20, 7), Position(20, 11), "Function 'even' is deprecated");
-    }
-
-    // @deprecated works for methods with a literal class name
-    {
-        LintResult result = lint(R"(
-Account = { balance=0 }
-
-@deprecated
-function Account:deposit(v)
-    self.balance = self.balance + v
-end
-    
-Account:deposit(200.00)
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(8, 0), Position(8, 15), "Member 'Account.deposit' is deprecated");
-    }
-
-    // @deprecated works for methods with a compound expression class name
-    {
-        LintResult result = lint(R"(
-Account = { balance=0 }
-
-function getAccount()
-    return Account
-end
-
-@deprecated
-function Account:deposit (v)
-    self.balance = self.balance + v
-end
-    
-(getAccount()):deposit(200.00)
-)");
-
-        REQUIRE(1 == result.warnings.size());
-        checkDeprecatedWarning(result.warnings[0], Position(12, 0), Position(12, 22), "Member 'deposit' is deprecated");
-    }
-}
-
-TEST_CASE_FIXTURE(Fixture, "DeprecatedAttributeFunctionDeclaration")
-{
-    ScopedFastFlag sff[] = {{FFlag::LuauDeprecatedAttribute, true}, {FFlag::LuauSolverV2, true}};
-
-    // @deprecated works on function type declarations
-
-    loadDefinition(R"(
-@deprecated declare function bar(x: number): string
-)");
-
-    LintResult result = lint(R"(
-bar(2)
-)");
-
-    REQUIRE(1 == result.warnings.size());
-    checkDeprecatedWarning(result.warnings[0], Position(1, 0), Position(1, 3), "Function 'bar' is deprecated");
-}
-
-TEST_CASE_FIXTURE(Fixture, "DeprecatedAttributeTableDeclaration")
-{
-    ScopedFastFlag sff[] = {{FFlag::LuauDeprecatedAttribute, true}, {FFlag::LuauSolverV2, true}};
-
-    // @deprecated works on table type declarations
-
-    loadDefinition(R"(
-declare Hooty : {
-    tooty : @deprecated @checked (number) -> number
-}
-)");
-
-    LintResult result = lint(R"(
-print(Hooty:tooty(2.0))
-)");
-
-    REQUIRE(1 == result.warnings.size());
-    checkDeprecatedWarning(result.warnings[0], Position(1, 6), Position(1, 17), "Member 'Hooty.tooty' is deprecated");
-}
-
-TEST_CASE_FIXTURE(Fixture, "DeprecatedAttributeMethodDeclaration")
-{
-    ScopedFastFlag sff[] = {{FFlag::LuauDeprecatedAttribute, true}, {FFlag::LuauSolverV2, true}};
-
-    // @deprecated works on table type declarations
-
-    loadDefinition(R"(
-declare class Foo
-   @deprecated
-   function bar(self, value: number) : number
-end
-
-declare Foo: {
-   new: () -> Foo
-}
-)");
-
-    LintResult result = lint(R"(
-local foo = Foo.new()
-print(foo:bar(2.0))
-)");
-
-    REQUIRE(1 == result.warnings.size());
-    checkDeprecatedWarning(result.warnings[0], Position(2, 6), Position(2, 13), "Member 'bar' is deprecated");
-}
-
 TEST_CASE_FIXTURE(BuiltinsFixture, "TableOperations")
 {
     LintResult result = lint(R"(

tests/NonStrictTypeChecker.test.cpp

@@ -17,8 +17,6 @@
 
 LUAU_FASTFLAG(LuauNewNonStrictWarnOnUnknownGlobals)
 LUAU_FASTFLAG(LuauNonStrictVisitorImprovements)
-LUAU_FASTFLAG(LuauNonStrictFuncDefErrorFix)
-LUAU_FASTFLAG(LuauNormalizedBufferIsNotUnknown)
 
 using namespace Luau;
 
@@ -361,23 +359,6 @@ end
     NONSTRICT_REQUIRE_FUNC_DEFINITION_ERR(Position(1, 11), "x", result);
 }
 
-TEST_CASE_FIXTURE(NonStrictTypeCheckerFixture, "function_def_sequencing_errors_2")
-{
-    ScopedFastFlag luauNonStrictFuncDefErrorFix{FFlag::LuauNonStrictFuncDefErrorFix, true};
-    ScopedFastFlag luauNonStrictVisitorImprovements{FFlag::LuauNonStrictVisitorImprovements, true};
-
-    CheckResult result = checkNonStrict(R"(
-local t = {function(x)
-    abs(x)
-    lower(x)
-end}
-)");
-    LUAU_REQUIRE_ERROR_COUNT(3, result);
-    NONSTRICT_REQUIRE_CHECKED_ERR(Position(2, 8), "abs", result);
-    NONSTRICT_REQUIRE_CHECKED_ERR(Position(3, 10), "lower", result);
-    CHECK(toString(result.errors[2]) == "Argument x with type 'unknown' is used in a way that will run time error");
-}
-
 TEST_CASE_FIXTURE(NonStrictTypeCheckerFixture, "local_fn_produces_error")
 {
     CheckResult result = checkNonStrict(R"(
@@ -668,17 +649,4 @@ TEST_CASE_FIXTURE(Fixture, "unknown_globals_in_non_strict")
     LUAU_REQUIRE_ERROR_COUNT(2, result);
 }
 
-TEST_CASE_FIXTURE(BuiltinsFixture, "buffer_is_not_unknown")
-{
-    ScopedFastFlag luauNormalizedBufferIsNotUnknown{FFlag::LuauNormalizedBufferIsNotUnknown, true};
-
-    CheckResult result = check(Mode::Nonstrict, R"(
-local function wrap(b: buffer, i: number, v: number)
-    buffer.writeu32(b, i * 4, v)
-end
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-}
-
 TEST_SUITE_END();

tests/Normalize.test.cpp

@@ -10,16 +10,10 @@
 #include "Luau/Normalize.h"
 #include "Luau/BuiltinDefinitions.h"
 
-LUAU_FASTFLAG(LuauNormalizeNegatedErrorToAnError)
-LUAU_FASTFLAG(LuauNormalizeIntersectErrorToAnError)
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTINT(LuauTypeInferRecursionLimit)
-LUAU_FASTINT(LuauNormalizeIntersectionLimit)
-LUAU_FASTINT(LuauNormalizeUnionLimit)
-LUAU_FASTFLAG(LuauNormalizeLimitFunctionSet)
-LUAU_FASTFLAG(LuauSubtypingStopAtNormFail)
-LUAU_FASTFLAG(LuauNormalizationCatchMetatableCycles)
-
+LUAU_FASTFLAG(LuauFixNormalizedIntersectionOfNegatedClass)
+LUAU_FASTFLAG(LuauNormalizeNegationFix)
 using namespace Luau;
 
 namespace
@@ -600,25 +594,6 @@ TEST_CASE_FIXTURE(NormalizeFixture, "intersect_truthy_expressed_as_intersection"
     )")));
 }
 
-TEST_CASE_FIXTURE(NormalizeFixture, "intersect_error")
-{
-    ScopedFastFlag luauNormalizeIntersectErrorToAnError{FFlag::LuauNormalizeIntersectErrorToAnError, true};
-
-    std::shared_ptr<const NormalizedType> norm = toNormalizedType(R"(string & AAA)", 1);
-    REQUIRE(norm);
-    CHECK("*error-type*" == toString(normalizer.typeFromNormal(*norm)));
-}
-
-TEST_CASE_FIXTURE(NormalizeFixture, "intersect_not_error")
-{
-    ScopedFastFlag luauNormalizeIntersectErrorToAnError{FFlag::LuauNormalizeIntersectErrorToAnError, true};
-    ScopedFastFlag luauNormalizeNegatedErrorToAnError{FFlag::LuauNormalizeNegatedErrorToAnError, true};
-
-    std::shared_ptr<const NormalizedType> norm = toNormalizedType(R"(string & Not<)", 1);
-    REQUIRE(norm);
-    CHECK("*error-type*" == toString(normalizer.typeFromNormal(*norm)));
-}
-
 TEST_CASE_FIXTURE(NormalizeFixture, "union_of_union")
 {
     CHECK(R"("alpha" | "beta" | "gamma")" == toString(normal(R"(
@@ -877,6 +852,7 @@ TEST_CASE_FIXTURE(NormalizeFixture, "crazy_metatable")
 
 TEST_CASE_FIXTURE(NormalizeFixture, "negations_of_classes")
 {
+    ScopedFastFlag _{FFlag::LuauFixNormalizedIntersectionOfNegatedClass, true};
     createSomeClasses(&frontend);
     CHECK("(Parent & ~Child) | Unrelated" == toString(normal("(Parent & Not<Child>) | Unrelated")));
     CHECK("((class & ~Child) | boolean | buffer | function | number | string | table | thread)?" == toString(normal("Not<Child>")));
@@ -1058,6 +1034,7 @@ TEST_CASE_FIXTURE(NormalizeFixture, "free_type_and_not_truthy")
 {
     ScopedFastFlag sff[] = {
         {FFlag::LuauSolverV2, true}, // Only because it affects the stringification of free types
+        {FFlag::LuauNormalizeNegationFix, true},
     };
 
     TypeId freeTy = arena.freshType(builtinTypes, &globalScope);
@@ -1073,19 +1050,6 @@ TEST_CASE_FIXTURE(NormalizeFixture, "free_type_and_not_truthy")
     CHECK("'a & (false?)" == toString(result));
 }
 
-TEST_CASE_FIXTURE(NormalizeFixture, "normalize_recursive_metatable")
-{
-    ScopedFastFlag sff[] = {{FFlag::LuauSolverV2, true}, {FFlag::LuauNormalizationCatchMetatableCycles, true}};
-
-    TypeId root = arena.addType(BlockedType{});
-    TypeId emptyTable = arena.addType(TableType(TableState::Sealed, {}));
-    TypeId metatable = arena.addType(MetatableType{emptyTable, root});
-    emplaceType<BoundType>(asMutable(root), metatable);
-    auto normalized = normalizer.normalize(root);
-    REQUIRE(normalized);
-    CHECK_EQ("t1 where t1 = { @metatable t1, {  } }", toString(normalizer.typeFromNormal(*normalized)));
-}
-
 TEST_CASE_FIXTURE(BuiltinsFixture, "normalizer_should_be_able_to_detect_cyclic_tables_and_not_stack_overflow")
 {
     if (!FFlag::LuauSolverV2)
@@ -1191,40 +1155,4 @@ end
 )");
 }
 
-TEST_CASE_FIXTURE(BuiltinsFixture, "fuzz_limit_function_intersection_complexity")
-{
-    ScopedFastInt luauNormalizeIntersectionLimit{FInt::LuauNormalizeIntersectionLimit, 50};
-    ScopedFastInt luauNormalizeUnionLimit{FInt::LuauNormalizeUnionLimit, 20};
-    ScopedFastFlag luauNormalizeLimitFunctionSet{FFlag::LuauNormalizeLimitFunctionSet, true};
-    ScopedFastFlag luauSubtypingStopAtNormFail{FFlag::LuauSubtypingStopAtNormFail, true};
-
-    CheckResult result = check(R"(
-function _(_).readu32(l0)
-return ({[_(_(_))]=_,[_(if _ then _)]=_,n0=_,})[_],nil
-end
-_(_)[_(n32)] %= _(_(_))
-    )");
-
-    LUAU_REQUIRE_ERRORS(result);
-}
-
-#if !(defined(_WIN32) && !(defined(_M_X64) || defined(_M_ARM64)))
-TEST_CASE_FIXTURE(BuiltinsFixture, "fuzz_propagate_normalization_failures")
-{
-    ScopedFastInt luauNormalizeIntersectionLimit{FInt::LuauNormalizeIntersectionLimit, 50};
-    ScopedFastInt luauNormalizeUnionLimit{FInt::LuauNormalizeUnionLimit, 20};
-    ScopedFastFlag luauNormalizeLimitFunctionSet{FFlag::LuauNormalizeLimitFunctionSet, true};
-    ScopedFastFlag luauSubtypingStopAtNormFail{FFlag::LuauSubtypingStopAtNormFail, true};
-
-    CheckResult result = check(R"(
-function _(_,"").readu32(l0)
-return ({[_(_(_))]=_,[_(if _ then _,_())]=_,[""]=_,})[_],nil
-end
-_().readu32 %= _(_(_(_),_))
-    )");
-
-    LUAU_REQUIRE_ERRORS(result);
-}
-#endif
-
 TEST_SUITE_END();

tests/Parser.test.cpp

@@ -18,17 +18,11 @@ LUAU_FASTINT(LuauParseErrorLimit)
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTFLAG(LuauAllowComplexTypesInGenericParams)
 LUAU_FASTFLAG(LuauErrorRecoveryForTableTypes)
+LUAU_FASTFLAG(LuauFixFunctionNameStartPosition)
 LUAU_FASTFLAG(LuauExtendStatEndPosWithSemicolon)
 LUAU_FASTFLAG(LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
 LUAU_FASTFLAG(LuauAstTypeGroup3)
 LUAU_FASTFLAG(LuauFixDoBlockEndLocation)
-LUAU_FASTFLAG(LuauParseOptionalAsNode2)
-LUAU_FASTFLAG(LuauParseStringIndexer)
-LUAU_FASTFLAG(LuauFixFunctionWithAttributesStartLocation)
-LUAU_DYNAMIC_FASTFLAG(DebugLuauReportReturnTypeVariadicWithTypeSuffix)
-
-// Clip with DebugLuauReportReturnTypeVariadicWithTypeSuffix
-extern bool luau_telemetry_parsed_return_type_variadic_with_type_suffix;
 
 namespace
 {
@@ -2546,40 +2540,6 @@ TEST_CASE_FIXTURE(Fixture, "do_block_end_location_is_after_end_token")
     CHECK_EQ(block->location, Location{{1, 8}, {3, 11}});
 }
 
-TEST_CASE_FIXTURE(Fixture, "function_start_locations_are_before_attributes")
-{
-    ScopedFastFlag _{FFlag::LuauFixFunctionWithAttributesStartLocation, true};
-
-    AstStatBlock* stat = parse(R"(
-        @native
-        function globalFunction()
-        end
-
-        @native
-        local function localFunction()
-        end
-
-        local _ = @native function()
-        end
-    )");
-    REQUIRE(stat);
-    REQUIRE_EQ(3, stat->body.size);
-
-    auto globalFunction = stat->body.data[0]->as<AstStatFunction>();
-    REQUIRE(globalFunction);
-    CHECK_EQ(globalFunction->location, Location({1, 8}, {3, 11}));
-
-    auto localFunction = stat->body.data[1]->as<AstStatLocalFunction>();
-    REQUIRE(localFunction);
-    CHECK_EQ(localFunction->location, Location({5, 8}, {7, 11}));
-
-    auto localVariable = stat->body.data[2]->as<AstStatLocal>();
-    REQUIRE(localVariable);
-    REQUIRE_EQ(localVariable->values.size, 1);
-    auto anonymousFunction = localVariable->values.data[0]->as<AstExprFunction>();
-    CHECK_EQ(anonymousFunction->location, Location({9, 18}, {10, 11}));
-}
-
 TEST_SUITE_END();
 
 TEST_SUITE_BEGIN("ParseErrorRecovery");
@@ -3858,10 +3818,7 @@ TEST_CASE_FIXTURE(Fixture, "grouped_function_type")
     }
     else
         CHECK(unionTy->types.data[0]->is<AstTypeFunction>()); // () -> ()
-    if (FFlag::LuauParseOptionalAsNode2)
-        CHECK(unionTy->types.data[1]->is<AstTypeOptional>()); // ?
-    else
-        CHECK(unionTy->types.data[1]->is<AstTypeReference>()); // nil
+    CHECK(unionTy->types.data[1]->is<AstTypeReference>());    // nil
 }
 
 TEST_CASE_FIXTURE(Fixture, "complex_union_in_generic_ty")
@@ -3919,6 +3876,7 @@ TEST_CASE_FIXTURE(Fixture, "recover_from_bad_table_type")
 
 TEST_CASE_FIXTURE(Fixture, "function_name_has_correct_start_location")
 {
+    ScopedFastFlag _{FFlag::LuauFixFunctionNameStartPosition, true};
     AstStatBlock* block = parse(R"(
         function simple()
         end
@@ -3967,8 +3925,6 @@ TEST_CASE_FIXTURE(Fixture, "stat_end_includes_semicolon_position")
 
 TEST_CASE_FIXTURE(Fixture, "parsing_type_suffix_for_return_type_with_variadic")
 {
-    ScopedFastFlag sff{DFFlag::DebugLuauReportReturnTypeVariadicWithTypeSuffix, true};
-
     ParseResult result = tryParse(R"(
         function foo(): (string, ...number) | boolean
         end
@@ -3976,13 +3932,7 @@ TEST_CASE_FIXTURE(Fixture, "parsing_type_suffix_for_return_type_with_variadic")
 
     // TODO(CLI-140667): this should produce a ParseError in future when we fix the invalid syntax
     CHECK(result.errors.size() == 0);
-    CHECK_EQ(luau_telemetry_parsed_return_type_variadic_with_type_suffix, true);
 }
 
-TEST_CASE_FIXTURE(Fixture, "parsing_string_union_indexers")
-{
-    ScopedFastFlag _{FFlag::LuauParseStringIndexer, true};
-    parse(R"(type foo = { ["bar" | "baz"]: number })");
-}
 
 TEST_SUITE_END();

tests/RequireTracer.test.cpp

@@ -6,6 +6,8 @@
 
 #include "doctest.h"
 
+LUAU_FASTFLAG(LuauExtendedSimpleRequire)
+
 using namespace Luau;
 
 namespace
@@ -180,6 +182,8 @@ TEST_CASE_FIXTURE(RequireTracerFixture, "follow_string_indexexpr")
 
 TEST_CASE_FIXTURE(RequireTracerFixture, "follow_group")
 {
+    ScopedFastFlag luauExtendedSimpleRequire{FFlag::LuauExtendedSimpleRequire, true};
+
     AstStatBlock* block = parse(R"(
         local R = (((game).Test))
         require(R)
@@ -196,6 +200,8 @@ TEST_CASE_FIXTURE(RequireTracerFixture, "follow_group")
 
 TEST_CASE_FIXTURE(RequireTracerFixture, "follow_type_annotation")
 {
+    ScopedFastFlag luauExtendedSimpleRequire{FFlag::LuauExtendedSimpleRequire, true};
+
     AstStatBlock* block = parse(R"(
         local R = game.Test :: (typeof(game.Redirect))
         require(R)
@@ -212,6 +218,8 @@ TEST_CASE_FIXTURE(RequireTracerFixture, "follow_type_annotation")
 
 TEST_CASE_FIXTURE(RequireTracerFixture, "follow_type_annotation_2")
 {
+    ScopedFastFlag luauExtendedSimpleRequire{FFlag::LuauExtendedSimpleRequire, true};
+
     AstStatBlock* block = parse(R"(
         local R = game.Test :: (typeof(game.Redirect))
         local N = R.Nested

tests/ScopedFlags.h

@@ -3,7 +3,7 @@
 
 #include "Luau/Common.h"
 
-#include <vector>
+#include <string.h>
 
 template<typename T>
 struct [[nodiscard]] ScopedFValue

tests/Subtyping.test.cpp

@@ -15,8 +15,7 @@
 
 #include <initializer_list>
 
-LUAU_FASTFLAG(LuauSolverV2)
-LUAU_FASTFLAG(LuauNormalizedBufferIsNotUnknown)
+LUAU_FASTFLAG(LuauSolverV2);
 
 using namespace Luau;
 
@@ -962,20 +961,6 @@ TEST_IS_NOT_SUBTYPE(childClass, negate(rootClass));
 TEST_IS_NOT_SUBTYPE(childClass, meet(builtinTypes->classType, negate(rootClass)));
 TEST_IS_SUBTYPE(anotherChildClass, meet(builtinTypes->classType, negate(childClass)));
 
-// Negated primitives against unknown
-TEST_IS_NOT_SUBTYPE(builtinTypes->unknownType, negate(builtinTypes->booleanType));
-TEST_IS_NOT_SUBTYPE(builtinTypes->unknownType, negate(builtinTypes->numberType));
-TEST_IS_NOT_SUBTYPE(builtinTypes->unknownType, negate(builtinTypes->stringType));
-TEST_IS_NOT_SUBTYPE(builtinTypes->unknownType, negate(builtinTypes->threadType));
-
-TEST_CASE_FIXTURE(SubtypeFixture, "unknown <!: ~buffer")
-{
-    // TODO: replace with TEST_IS_NOT_SUBTYPE on flag removal
-    ScopedFastFlag luauNormalizedBufferIsNotUnknown{FFlag::LuauNormalizedBufferIsNotUnknown, true};
-
-    CHECK_IS_NOT_SUBTYPE(builtinTypes->unknownType, negate(builtinTypes->bufferType));
-}
-
 TEST_CASE_FIXTURE(SubtypeFixture, "Root <: class")
 {
     CHECK_IS_SUBTYPE(rootClass, builtinTypes->classType);

tests/ToString.test.cpp

@@ -5,16 +5,14 @@
 
 #include "Fixture.h"
 
-#include "Luau/TypeChecker2.h"
 #include "ScopedFlags.h"
 #include "doctest.h"
 
 using namespace Luau;
 
-LUAU_FASTFLAG(LuauRecursiveTypeParameterRestriction)
-LUAU_FASTFLAG(LuauSolverV2)
-LUAU_FASTFLAG(LuauAttributeSyntax)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
+LUAU_FASTFLAG(LuauRecursiveTypeParameterRestriction);
+LUAU_FASTFLAG(LuauSolverV2);
+LUAU_FASTFLAG(LuauAttributeSyntax);
 
 TEST_SUITE_BEGIN("ToString");
 
@@ -873,28 +871,9 @@ TEST_CASE_FIXTURE(Fixture, "tostring_error_mismatch")
     )");
 
     std::string expected;
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-        expected =
-            "Type pack '{ a: number, b: string, c: { d: string } }' could not be converted into '{ a: number, b: string, c: { d: number } }'; \n"
-            "this is because in the 1st entry in the type pack, accessing `c.d` results in `string` in the former type and `number` in the latter "
-            "type, and `string` is not exactly `number`";
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
         expected =
             R"(Type pack '{ a: number, b: string, c: { d: string } }' could not be converted into '{ a: number, b: string, c: { d: number } }'; at [0][read "c"][read "d"], string is not exactly number)";
-    else if (FFlag::LuauImproveTypePathsInErrors)
-        expected = R"(Type
-	'{ a: number, b: string, c: { d: string } }'
-could not be converted into
-	'{| a: number, b: string, c: {| d: number |} |}'
-caused by:
-  Property 'c' is not compatible.
-Type
-	'{ d: string }'
-could not be converted into
-	'{| d: number |}'
-caused by:
-  Property 'd' is not compatible.
-Type 'string' could not be converted into 'number' in an invariant context)";
     else
         expected = R"(Type
     '{ a: number, b: string, c: { d: string } }'

tests/TypeFunction.test.cpp

@@ -13,15 +13,8 @@
 using namespace Luau;
 
 LUAU_FASTFLAG(LuauSolverV2)
-LUAU_FASTFLAG(LuauIndexTypeFunctionImprovements)
 LUAU_DYNAMIC_FASTINT(LuauTypeFamilyApplicationCartesianProductLimit)
-LUAU_FASTFLAG(LuauIndexTypeFunctionFunctionMetamethods)
 LUAU_FASTFLAG(LuauMetatableTypeFunctions)
-LUAU_FASTFLAG(LuauMetatablesHaveLength)
-LUAU_FASTFLAG(LuauIndexAnyIsAny)
-LUAU_FASTFLAG(LuauNewTypeFunReductionChecks2)
-LUAU_FASTFLAG(LuauHasPropProperBlock)
-LUAU_FASTFLAG(LuauFixCyclicIndexInIndexer)
 
 struct TypeFunctionFixture : Fixture
 {
@@ -149,17 +142,19 @@ TEST_CASE_FIXTURE(TypeFunctionFixture, "unsolvable_function")
     if (!FFlag::LuauSolverV2)
         return;
 
-    ScopedFastFlag luauNewTypeFunReductionChecks2{FFlag::LuauNewTypeFunReductionChecks2, true};
-
     CheckResult result = check(R"(
         local impossible: <T>(Swap<T>) -> Swap<Swap<T>>
         local a = impossible(123)
         local b = impossible(true)
     )");
 
-    LUAU_REQUIRE_ERROR_COUNT(2, result);
-    CHECK(toString(result.errors[0]) == "Type 'number' could not be converted into 'never'");
-    CHECK(toString(result.errors[1]) == "Type 'boolean' could not be converted into 'never'");
+    LUAU_REQUIRE_ERROR_COUNT(6, result);
+    CHECK(toString(result.errors[0]) == "Type function instance Swap<Swap<T>> is uninhabited");
+    CHECK(toString(result.errors[1]) == "Type function instance Swap<T> is uninhabited");
+    CHECK(toString(result.errors[2]) == "Type function instance Swap<Swap<T>> is uninhabited");
+    CHECK(toString(result.errors[3]) == "Type function instance Swap<T> is uninhabited");
+    CHECK(toString(result.errors[4]) == "Type function instance Swap<Swap<T>> is uninhabited");
+    CHECK(toString(result.errors[5]) == "Type function instance Swap<T> is uninhabited");
 }
 
 TEST_CASE_FIXTURE(TypeFunctionFixture, "table_internal_functions")
@@ -909,91 +904,6 @@ end
     LUAU_REQUIRE_NO_ERRORS(result);
 }
 
-TEST_CASE_FIXTURE(BuiltinsFixture, "index_of_any_is_any")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    ScopedFastFlag sff{FFlag::LuauIndexAnyIsAny, true};
-
-    CheckResult result = check(R"(
-        type T = index<any, "a">
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-    CHECK(toString(requireTypeAlias("T")) == "any");
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "index_should_not_crash_on_cyclic_stuff")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    ScopedFastFlag sff{FFlag::LuauFixCyclicIndexInIndexer, true};
-
-    CheckResult result = check(R"(
-        local PlayerData = {}
-
-        type Keys = index<typeof(PlayerData), true>
-
-        local function UpdateData(key: Keys)
-            PlayerData[key] = 4
-        end
-    )");
-
-    LUAU_REQUIRE_ERRORS(result);
-    CHECK(toString(requireTypeAlias("Keys")) == "index<PlayerData, true>");
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "index_should_not_crash_on_cyclic_stuff2")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    ScopedFastFlag sff{FFlag::LuauFixCyclicIndexInIndexer, true};
-
-    CheckResult result = check(R"(
-        local PlayerData = {}
-
-        type Keys = index<typeof(PlayerData), number>
-
-        local function UpdateData(key: Keys)
-            PlayerData[key] = 4
-        end
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-    CHECK(toString(requireTypeAlias("Keys")) == "number");
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "index_should_not_crash_on_cyclic_stuff3")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    ScopedFastFlag sff{FFlag::LuauFixCyclicIndexInIndexer, true};
-
-    CheckResult result = check(R"(
-        local PlayerData = {
-            Coins = 0,
-            Level = 1,
-            Exp = 0,
-            MapExp = 100,
-        }
-
-        type Keys = index<typeof(PlayerData), true>
-
-        local function UpdateData(key: Keys, value)
-            PlayerData[key] = value
-        end
-
-        UpdateData("Coins", 2)
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-    CHECK(toString(requireTypeAlias("Keys")) == "unknown");
-}
-
 TEST_CASE_FIXTURE(BuiltinsFixture, "index_type_function_works")
 {
     if (!FFlag::LuauSolverV2)
@@ -1055,31 +965,6 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "index_type_function_works_w_array")
     LUAU_REQUIRE_NO_ERRORS(result);
 }
 
-TEST_CASE_FIXTURE(BuiltinsFixture, "cyclic_metatable_should_not_crash_index")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    ScopedFastFlag sff{FFlag::LuauIndexTypeFunctionImprovements, true};
-
-    // t :: t1 where t1 = {metatable {__index: t1, __tostring: (t1) -> string}}
-    CheckResult result = check(R"(
-        local mt = {}
-        local t = setmetatable({}, mt)
-        mt.__index = t
-
-        function mt:__tostring()
-            return t.p
-        end
-
-        type IndexFromT = index<typeof(t), "p">
-    )");
-
-    LUAU_REQUIRE_ERROR_COUNT(2, result);
-    CHECK_EQ("Type 't' does not have key 'p'", toString(result.errors[0]));
-    CHECK_EQ("Property '\"p\"' does not exist on type 't'", toString(result.errors[1]));
-}
-
 TEST_CASE_FIXTURE(BuiltinsFixture, "index_type_function_works_w_generic_types")
 {
     if (!FFlag::LuauSolverV2)
@@ -1118,61 +1003,6 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "index_type_function_errors_w_bad_indexer")
     CHECK(toString(result.errors[1]) == "Property 'boolean' does not exist on type 'MyObject'");
 }
 
-TEST_CASE_FIXTURE(BuiltinsFixture, "index_type_function_works_on_function_metamethods")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    ScopedFastFlag sff[]
-    {
-        {FFlag::LuauIndexTypeFunctionFunctionMetamethods, true},
-        {FFlag::LuauIndexTypeFunctionImprovements, true},
-    };
-
-    CheckResult result = check(R"(
-        type Foo = {x: string}
-        local t = {}
-        setmetatable(t, {
-            __index = function(x: string): Foo
-                return {x = x}
-            end
-        })
-
-        type Bar = index<typeof(t), "bar">
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-
-
-    CHECK_EQ(toString(requireTypeAlias("Bar"), {true}), "{ x: string }");
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "index_type_function_works_on_function_metamethods2")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    ScopedFastFlag sff[]
-    {
-        {FFlag::LuauIndexTypeFunctionFunctionMetamethods, true},
-        {FFlag::LuauIndexTypeFunctionImprovements, true},
-    };
-
-    CheckResult result = check(R"(
-        type Foo = {x: string}
-        local t = {}
-        setmetatable(t, {
-            __index = function(x: string): Foo
-                return {x = x}
-            end
-        })
-
-        type Bar = index<typeof(t), number>
-    )");
-
-    LUAU_REQUIRE_ERROR_COUNT(1, result);
-}
-
 TEST_CASE_FIXTURE(BuiltinsFixture, "index_type_function_errors_w_var_indexer")
 {
     if (!FFlag::LuauSolverV2)
@@ -1624,53 +1454,4 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "getmetatable_respects_metatable_metamethod")
     CHECK_EQ(toString(requireTypeAlias("Metatable")), "string");
 }
 
-TEST_CASE_FIXTURE(BuiltinsFixture, "type_function_correct_cycle_check")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    ScopedFastFlag luauNewTypeFunReductionChecks2{FFlag::LuauNewTypeFunReductionChecks2, true};
-
-    CheckResult result = check(R"(
-type foo<T> = { a: add<T, T>, b : add<T, T> }
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "len_typefun_on_metatable")
-{
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-    ScopedFastFlag luauMetatablesHaveLength{FFlag::LuauMetatablesHaveLength, true};
-
-    CheckResult result = check(R"(
-local t = setmetatable({}, { __mode = "v" })
-
-local function f()
-    table.insert(t, {})
-    print(#t * 100)
-end
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "has_prop_on_irreducible_type_function")
-{
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-    ScopedFastFlag luauHasPropProperBlock{FFlag::LuauHasPropProperBlock, true};
-
-    CheckResult result = check(R"(
-local test = "a" + "b"
-print(test.a)
-    )");
-
-    LUAU_REQUIRE_ERROR_COUNT(2, result);
-    CHECK(
-        "Operator '+' could not be applied to operands of types string and string; there is no corresponding overload for __add" ==
-        toString(result.errors[0])
-    );
-    CHECK("Type 'add<string, string>' does not have key 'a'" == toString(result.errors[1]));
-}
-
 TEST_SUITE_END();

tests/TypeFunction.user.test.cpp

@@ -7,12 +7,13 @@
 
 using namespace Luau;
 
+LUAU_FASTFLAG(LuauTypeFunFixHydratedClasses)
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTFLAG(DebugLuauEqSatSimplification)
+LUAU_FASTFLAG(LuauTypeFunSingletonEquality)
+LUAU_FASTFLAG(LuauUserTypeFunTypeofReturnsType)
 LUAU_FASTFLAG(LuauTypeFunReadWriteParents)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
-LUAU_FASTFLAG(LuauUserTypeFunTypecheck)
-LUAU_FASTFLAG(LuauNewTypeFunReductionChecks2)
+LUAU_FASTFLAG(LuauTypeFunPrintFix)
 
 TEST_SUITE_BEGIN("UserDefinedTypeFunctionTests");
 
@@ -612,12 +613,9 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_function_methods_work")
             ty:setreturns(nil, types.boolean) -- (string, number) -> (...boolean)
             if ty:is("function") then
                 -- creating a copy of `ty` parameters
-                local arr: {type} = {}
-                local args = ty:parameters().head
-                if args then
-                    for index, val in args do
-                        table.insert(arr, val)
-                    end
+                local arr = {}
+                for index, val in ty:parameters().head do
+                    table.insert(arr, val)
                 end
                 return types.newfunction({head = arr}, ty:returns()) -- (string, number) -> (...boolean)
             end
@@ -650,6 +648,7 @@ TEST_CASE_FIXTURE(ClassFixture, "udtf_class_serialization_works")
 TEST_CASE_FIXTURE(ClassFixture, "udtf_class_serialization_works2")
 {
     ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
+    ScopedFastFlag luauTypeFunFixHydratedClasses{FFlag::LuauTypeFunFixHydratedClasses, true};
 
     CheckResult result = check(R"(
         type function serialize_class(arg)
@@ -720,7 +719,7 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_check_mutability")
                 readresult = types.boolean,
                 writeresult = types.boolean,
             }
-            local ty = types.newtable(nil, indexer, nil) -- {[number]: boolean}
+            local ty = types.newtable(props, indexer, nil) -- {[number]: boolean}
             ty:setproperty(types.singleton("string"), types.number) -- {string: number, [number]: boolean}
             local metatbl = types.newtable(nil, nil, ty) -- { {  }, @metatable { [number]: boolean, string: number } }
             -- mutate the table
@@ -895,7 +894,6 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_type_overrides_eq_metamethod")
             if p1 == p2 and t1 == t2 then
                 return types.number
             end
-            return types.unknown
         end
         local function ok(idx: hello<>): number return idx end
     )");
@@ -990,37 +988,8 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_calling_each_other_3")
         end
     )");
 
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(5, result);
-        CHECK(toString(result.errors[0]) == R"(Unknown global 'fourth')");
-        CHECK(toString(result.errors[1]) == R"('third' type function errored at runtime: [string "first"]:4: attempt to call a nil value)");
-    }
-    else
-    {
-        LUAU_REQUIRE_ERROR_COUNT(4, result);
-        CHECK(toString(result.errors[0]) == R"('third' type function errored at runtime: [string "first"]:4: attempt to call a nil value)");
-    }
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_calling_each_other_unordered")
-{
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-
-    CheckResult result = check(R"(
-        type function bar()
-            return types.singleton(foo())
-        end
-        type function foo()
-            return "hi"
-        end
-        local function ok(idx: bar<>): nil return idx end
-    )");
-
-    LUAU_REQUIRE_ERROR_COUNT(1, result);
-    TypePackMismatch* tpm = get<TypePackMismatch>(result.errors[0]);
-    REQUIRE(tpm);
-    CHECK(toString(tpm->givenTp) == "\"hi\"");
+    LUAU_REQUIRE_ERROR_COUNT(4, result);
+    CHECK(toString(result.errors[0]) == R"('third' type function errored at runtime: [string "first"]:4: attempt to call a nil value)");
 }
 
 TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_no_shared_state")
@@ -1044,21 +1013,10 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_no_shared_state")
         local function ok2(idx: bar<'y'>): nil return idx end
     )");
 
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // We are only checking first errors, others are mostly duplicates
-        LUAU_REQUIRE_ERROR_COUNT(9, result);
-        CHECK(toString(result.errors[0]) == R"(Unknown global 'glob')");
-        CHECK(toString(result.errors[1]) == R"('bar' type function errored at runtime: [string "foo"]:4: attempt to modify a readonly table)");
-        CHECK(toString(result.errors[2]) == R"(Type function instance bar<"x"> is uninhabited)");
-    }
-    else
-    {
-        // We are only checking first errors, others are mostly duplicates
-        LUAU_REQUIRE_ERROR_COUNT(8, result);
-        CHECK(toString(result.errors[0]) == R"('bar' type function errored at runtime: [string "foo"]:4: attempt to modify a readonly table)");
-        CHECK(toString(result.errors[1]) == R"(Type function instance bar<"x"> is uninhabited)");
-    }
+    // We are only checking first errors, others are mostly duplicates
+    LUAU_REQUIRE_ERROR_COUNT(8, result);
+    CHECK(toString(result.errors[0]) == R"('bar' type function errored at runtime: [string "foo"]:4: attempt to modify a readonly table)");
+    CHECK(toString(result.errors[1]) == R"(Type function instance bar<"x"> is uninhabited)");
 }
 
 TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_math_reset")
@@ -1117,23 +1075,10 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_calling_illegal_global")
         local function ok(idx: illegal<number>): nil return idx end
     )");
 
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // We are only checking first errors, others are mostly duplicates
-        LUAU_REQUIRE_ERROR_COUNT(5, result);
-        CHECK(toString(result.errors[0]) == R"(Unknown global 'gcinfo')");
-        CHECK(
-            toString(result.errors[1]) ==
-            R"('illegal' type function errored at runtime: [string "illegal"]:3: this function is not supported in type functions)"
-        );
-    }
-    else
-    {
-        LUAU_REQUIRE_ERROR_COUNT(4, result); // There are 2 type function uninhabited error, 2 user defined type function error
-        UserDefinedTypeFunctionError* e = get<UserDefinedTypeFunctionError>(result.errors[0]);
-        REQUIRE(e);
-        CHECK(e->message == "'illegal' type function errored at runtime: [string \"illegal\"]:3: this function is not supported in type functions");
-    }
+    LUAU_REQUIRE_ERROR_COUNT(4, result); // There are 2 type function uninhabited error, 2 user defined type function error
+    UserDefinedTypeFunctionError* e = get<UserDefinedTypeFunctionError>(result.errors[0]);
+    REQUIRE(e);
+    CHECK(e->message == "'illegal' type function errored at runtime: [string \"illegal\"]:3: this function is not supported in type functions");
 }
 
 TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_recursion_and_gc")
@@ -1227,7 +1172,7 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "no_type_methods_on_types")
 
     CheckResult result = check(R"(
         type function test(x)
-            return if (types :: any).is(x, "number") then types.string else types.boolean
+            return if types.is(x, "number") then types.string else types.boolean
         end
         local function ok(tbl: test<number>): never return tbl end
     )");
@@ -1298,36 +1243,9 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "tag_field")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(3, result);
-
-    if (FFlag::LuauImproveTypePathsInErrors)
-    {
-
-        CHECK(
-            toString(result.errors[0]) ==
-            "Type pack '\"number\"' could not be converted into 'never'; \n"
-            R"(this is because the 1st entry in the type pack is `"number"` in the former type and `never` in the latter type, and `"number"` is not a subtype of `never`)"
-        );
-        CHECK(
-            toString(result.errors[1]) ==
-            "Type pack '\"string\"' could not be converted into 'never'; \n"
-            R"(this is because the 1st entry in the type pack is `"string"` in the former type and `never` in the latter type, and `"string"` is not a subtype of `never`)"
-        );
-        CHECK(
-            toString(result.errors[2]) ==
-            "Type pack '\"table\"' could not be converted into 'never'; \n"
-            R"(this is because the 1st entry in the type pack is `"table"` in the former type and `never` in the latter type, and `"table"` is not a subtype of `never`)"
-        );
-    }
-    else
-    {
-        CHECK(
-            toString(result.errors[0]) == R"(Type pack '"number"' could not be converted into 'never'; at [0], "number" is not a subtype of never)"
-        );
-        CHECK(
-            toString(result.errors[1]) == R"(Type pack '"string"' could not be converted into 'never'; at [0], "string" is not a subtype of never)"
-        );
-        CHECK(toString(result.errors[2]) == R"(Type pack '"table"' could not be converted into 'never'; at [0], "table" is not a subtype of never)");
-    }
+    CHECK(toString(result.errors[0]) == R"(Type pack '"number"' could not be converted into 'never'; at [0], "number" is not a subtype of never)");
+    CHECK(toString(result.errors[1]) == R"(Type pack '"string"' could not be converted into 'never'; at [0], "string" is not a subtype of never)");
+    CHECK(toString(result.errors[2]) == R"(Type pack '"table"' could not be converted into 'never'; at [0], "table" is not a subtype of never)");
 }
 
 TEST_CASE_FIXTURE(BuiltinsFixture, "metatable_serialization")
@@ -1375,12 +1293,8 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "implicit_export")
     ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
 
     fileResolver.source["game/A"] = R"(
-type function concat(a: type, b: type)
-    local as = a:value()
-    local bs = b:value()
-    assert(typeof(as) == "string")
-    assert(typeof(bs) == "string")
-    return types.singleton(as .. bs)
+type function concat(a, b)
+    return types.singleton(a:value() .. b:value())
 end
 export type Concat<T, U> = concat<T, U>
 local a: concat<'first', 'second'>
@@ -1428,12 +1342,8 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "explicit_export")
     ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
 
     fileResolver.source["game/A"] = R"(
-export type function concat(a: type, b: type)
-    local as = a:value()
-    local bs = b:value()
-    assert(typeof(as) == "string")
-    assert(typeof(bs) == "string")
-    return types.singleton(as .. bs)
+export type function concat(a, b)
+    return types.singleton(a:value() .. b:value())
 end
 local a: concat<'first', 'second'>
 return {}
@@ -1982,6 +1892,7 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_eqsat_opaque")
 TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_singleton_equality_bool")
 {
     ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
+    ScopedFastFlag luauTypeFunSingletonEquality{FFlag::LuauTypeFunSingletonEquality, true};
 
     CheckResult result = check(R"(
 type function compare(arg)
@@ -1998,6 +1909,7 @@ local function ok(idx: compare<true>): false return idx end
 TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_singleton_equality_string")
 {
     ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
+    ScopedFastFlag luauTypeFunSingletonEquality{FFlag::LuauTypeFunSingletonEquality, true};
 
     CheckResult result = check(R"(
 type function compare(arg)
@@ -2014,6 +1926,7 @@ local function ok(idx: compare<"a">): false return idx end
 TEST_CASE_FIXTURE(BuiltinsFixture, "typeof_type_userdata_returns_type")
 {
     ScopedFastFlag solverV2{FFlag::LuauSolverV2, true};
+    ScopedFastFlag luauUserTypeFunTypeofReturnsType{FFlag::LuauUserTypeFunTypeofReturnsType, true};
 
     CheckResult result = check(R"(
 type function test(t)
@@ -2030,7 +1943,7 @@ local _:test<number>
 
 TEST_CASE_FIXTURE(BuiltinsFixture, "udtf_print_tab_char_fix")
 {
-    ScopedFastFlag solverV2{FFlag::LuauSolverV2, true};
+    ScopedFastFlag sffs[] = {{FFlag::LuauSolverV2, true}, {FFlag::LuauTypeFunPrintFix, true}};
 
     CheckResult result = check(R"(
         type function test(t)
@@ -2069,139 +1982,4 @@ TEST_CASE_FIXTURE(ClassFixture, "udtf_class_parent_ops")
     LUAU_REQUIRE_NO_ERRORS(result);
 }
 
-TEST_CASE_FIXTURE(BuiltinsFixture, "typecheck_success")
-{
-    // Needs new global initialization in the Fixture, but can't place the flag inside the base Fixture
-    if (!FFlag::LuauUserTypeFunTypecheck)
-        return;
-
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-
-    CheckResult result = check(R"(
-type function foo(x: type)
-    return types.singleton(x.tag)
-end
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "typecheck_failure")
-{
-    // Needs new global initialization in the Fixture, but can't place the flag inside the base Fixture
-    if (!FFlag::LuauUserTypeFunTypecheck)
-        return;
-
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-
-    CheckResult result = check(R"(
-type function foo()
-    return types.singleton({1})
-end
-    )");
-
-    LUAU_REQUIRE_ERROR_COUNT(1, result);
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "outer_generics_irreducible")
-{
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-    ScopedFastFlag luauNewTypeFunReductionChecks2{FFlag::LuauNewTypeFunReductionChecks2, true};
-
-    CheckResult result = check(R"(
-type function func(t)
-    return t
-end
-
-type wrap<T> = { a: func<T?> }
-
-local x: wrap<string> = nil :: any
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-
-    CHECK(toString(requireType("x"), ToStringOptions{true}) == "{ a: string? }");
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "inner_generics_reducible")
-{
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-
-    CheckResult result = check(R"(
-type function func(t)
-    return t
-end
-
-type wrap<T> = { a: func<<T>(T) -> number>, b: T }
-
-local x: wrap<string> = nil :: any
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-
-    CHECK(toString(requireType("x"), ToStringOptions{true}) == "{ a: <T>(T) -> number, b: string }");
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "blocking_nested_pending_expansions")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    CheckResult result = check(R"(
-type function func(t)
-    return t
-end
-
-type test<T> = { x: T, y: T? }
-type wrap<T> = { a: func<(string, keyof<test<T>>) -> number>, b: T }
-local x: wrap<string>
-local y: keyof<typeof(x)>
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-
-    CHECK(toString(requireType("x"), ToStringOptions{true}) == R"({ a: (string, "x" | "y") -> number, b: string })");
-    CHECK(toString(requireType("y"), ToStringOptions{true}) == R"("a" | "b")");
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "blocking_nested_pending_expansions_2")
-{
-    ScopedFastFlag newSolver{FFlag::LuauSolverV2, true};
-
-    CheckResult result = check(R"(
-type function foo(t)
-    return types.unionof(t, types.singleton(nil))
-end
-
-local x: foo<{a: foo<string>, b: foo<number>}> = nil
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-
-    CHECK(toString(requireType("x"), ToStringOptions{true}) == "{ a: string?, b: number? }?");
-}
-
-TEST_CASE_FIXTURE(BuiltinsFixture, "irreducible_pending_expansions")
-{
-    if (!FFlag::LuauSolverV2)
-        return;
-
-    ScopedFastFlag luauNewTypeFunReductionChecks2{FFlag::LuauNewTypeFunReductionChecks2, true};
-
-    CheckResult result = check(R"(
-type function foo(t)
-    return types.unionof(t, types.singleton(nil))
-end
-
-type table<T> = { a: index<T, "a"> }
-type wrap<T> = foo<table<T>>
-
-local x: wrap<{a: number}> = { a = 2 }
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-
-    CHECK(toString(requireType("x"), ToStringOptions{true}) == "{ a: number }?");
-}
-
 TEST_SUITE_END();

tests/TypeInfer.aliases.test.cpp

@@ -11,10 +11,6 @@ using namespace Luau;
 
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTFLAG(LuauFixInfiniteRecursionInNormalization)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
-LUAU_FASTFLAG(LuauBidirectionalInferenceUpcast)
-LUAU_FASTFLAG(LuauBidirectionalInferenceCollectIndexerTypes)
-LUAU_FASTFLAG(LuauRetainDefinitionAliasLocations)
 
 TEST_SUITE_BEGIN("TypeAliases");
 
@@ -220,11 +216,7 @@ TEST_CASE_FIXTURE(Fixture, "generic_aliases")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-    const std::string expected = (FFlag::LuauImproveTypePathsInErrors)
-                                     ? "Type '{ v: string }' could not be converted into 'T<number>'; \n"
-                                       "this is because accessing `v` results in `string` in the former type and `number` in the latter type, and "
-                                       "`string` is not exactly `number`"
-                                     : R"(Type '{ v: string }' could not be converted into 'T<number>'; at [read "v"], string is not exactly number)";
+    const std::string expected = R"(Type '{ v: string }' could not be converted into 'T<number>'; at [read "v"], string is not exactly number)";
     CHECK(result.errors[0].location == Location{{4, 31}, {4, 44}});
     CHECK_EQ(expected, toString(result.errors[0]));
 }
@@ -244,11 +236,7 @@ TEST_CASE_FIXTURE(Fixture, "dependent_generic_aliases")
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
     const std::string expected =
-        (FFlag::LuauImproveTypePathsInErrors)
-            ? "Type '{ t: { v: string } }' could not be converted into 'U<number>'; \n"
-              "this is because accessing `t.v` results in `string` in the former type and `number` in the latter type, and `string` is not exactly "
-              "`number`"
-            : R"(Type '{ t: { v: string } }' could not be converted into 'U<number>'; at [read "t"][read "v"], string is not exactly number)";
+        R"(Type '{ t: { v: string } }' could not be converted into 'U<number>'; at [read "t"][read "v"], string is not exactly number)";
 
     CHECK(result.errors[0].location == Location{{4, 31}, {4, 52}});
     CHECK_EQ(expected, toString(result.errors[0]));
@@ -256,10 +244,8 @@ TEST_CASE_FIXTURE(Fixture, "dependent_generic_aliases")
 
 TEST_CASE_FIXTURE(Fixture, "mutually_recursive_generic_aliases")
 {
-    ScopedFastFlag sffs[] = {
-        {FFlag::LuauBidirectionalInferenceUpcast, true},
-        {FFlag::LuauBidirectionalInferenceCollectIndexerTypes, true},
-    };
+    // CLI-116108
+    DOES_NOT_PASS_NEW_SOLVER_GUARD();
 
     CheckResult result = check(R"(
         --!strict
@@ -1223,40 +1209,4 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "gh1632_no_infinite_recursion_in_normalizatio
     LUAU_CHECK_NO_ERRORS(result);
 }
 
-TEST_CASE_FIXTURE(Fixture, "exported_alias_location_is_accessible_on_module")
-{
-    ScopedFastFlag sff{FFlag::LuauRetainDefinitionAliasLocations, true};
-
-    CheckResult result = check(R"(
-        export type Value = string
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-
-    auto module = getMainModule();
-    auto tfun = module->exportedTypeBindings.find("Value");
-    REQUIRE(tfun != module->exportedTypeBindings.end());
-    CHECK_EQ(tfun->second.definitionLocation, Location{{1, 8}, {1, 34}});
-}
-
-TEST_CASE_FIXTURE(Fixture, "exported_type_function_location_is_accessible_on_module")
-{
-    ScopedFastFlag flags[] = {
-        {FFlag::LuauSolverV2, true},
-        {FFlag::LuauRetainDefinitionAliasLocations, true},
-    };
-
-    CheckResult result = check(R"(
-        export type function Apply()
-        end
-    )");
-
-    LUAU_REQUIRE_NO_ERRORS(result);
-
-    auto module = getMainModule();
-    auto tfun = module->exportedTypeBindings.find("Apply");
-    REQUIRE(tfun != module->exportedTypeBindings.end());
-    CHECK_EQ(tfun->second.definitionLocation, Location{{1, 8}, {2, 11}});
-}
-
 TEST_SUITE_END();

tests/TypeInfer.builtins.test.cpp

@@ -11,7 +11,8 @@ using namespace Luau;
 
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTFLAG(LuauTableCloneClonesType3)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
+LUAU_FASTFLAG(LuauStringFormatErrorSuppression)
+LUAU_FASTFLAG(LuauFreezeIgnorePersistent)
 
 TEST_SUITE_BEGIN("BuiltinTests");
 
@@ -145,20 +146,7 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "sort_with_bad_predicate")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-    const std::string expected = (FFlag::LuauImproveTypePathsInErrors) ? "Type\n\t"
-                                                                         "'(number, number) -> boolean'"
-                                                                         "\ncould not be converted into\n\t"
-                                                                         "'((string, string) -> boolean)?'"
-                                                                         "\ncaused by:\n"
-                                                                         "  None of the union options are compatible. For example:\n"
-                                                                         "Type\n\t"
-                                                                         "'(number, number) -> boolean'"
-                                                                         "\ncould not be converted into\n\t"
-                                                                         "'(string, string) -> boolean'"
-                                                                         "\ncaused by:\n"
-                                                                         "  Argument #1 type is not compatible.\n"
-                                                                         "Type 'string' could not be converted into 'number'"
-                                                                       : R"(Type
+    const std::string expected = R"(Type
     '(number, number) -> boolean'
 could not be converted into
     '((string, string) -> boolean)?'
@@ -997,14 +985,7 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "tonumber_returns_optional_number_type")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-        CHECK_EQ(
-            "Type 'number?' could not be converted into 'number'; \n"
-            "this is because the 2nd component of the union is `nil`, which is not a subtype of `number`",
-            toString(result.errors[0])
-        );
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
         CHECK_EQ(
             "Type 'number?' could not be converted into 'number'; type number?[1] (nil) is not a subtype of number (number)",
             toString(result.errors[0])
@@ -1275,6 +1256,8 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "table_freeze_errors_on_non_tables")
 
 TEST_CASE_FIXTURE(BuiltinsFixture, "table_freeze_persistent_skip")
 {
+    ScopedFastFlag luauFreezeIgnorePersistent{FFlag::LuauFreezeIgnorePersistent, true};
+
     CheckResult result = check(R"(
         table.freeze(table)
     )");
@@ -1284,6 +1267,8 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "table_freeze_persistent_skip")
 
 TEST_CASE_FIXTURE(BuiltinsFixture, "table_clone_persistent_skip")
 {
+    ScopedFastFlag luauFreezeIgnorePersistent{FFlag::LuauFreezeIgnorePersistent, true};
+
     CheckResult result = check(R"(
         table.clone(table)
     )");
@@ -1671,7 +1656,10 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "string_format_should_support_any")
         print(string.format("Hello, %s!", x))
     )");
 
-    LUAU_REQUIRE_NO_ERRORS(result);
+    if (FFlag::LuauStringFormatErrorSuppression)
+        LUAU_REQUIRE_NO_ERRORS(result);
+    else
+        LUAU_REQUIRE_ERROR_COUNT(1, result);
 }
 
 TEST_SUITE_END();

tests/TypeInfer.classes.test.cpp

@@ -13,8 +13,7 @@
 using namespace Luau;
 using std::nullopt;
 
-LUAU_FASTFLAG(LuauSolverV2)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
+LUAU_FASTFLAG(LuauSolverV2);
 
 TEST_SUITE_BEGIN("TypeInferClasses");
 
@@ -546,13 +545,7 @@ local b: B = a
 
     LUAU_REQUIRE_ERRORS(result);
 
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-        CHECK(
-            "Type 'A' could not be converted into 'B'; \n"
-            "this is because accessing `x` results in `ChildClass` in the former type and `BaseClass` in the latter type, and `ChildClass` is not "
-            "exactly `BaseClass`" == toString(result.errors.at(0))
-        );
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
         CHECK(toString(result.errors.at(0)) == "Type 'A' could not be converted into 'B'; at [read \"x\"], ChildClass is not exactly BaseClass");
     else
     {

tests/TypeInfer.definitions.test.cpp

@@ -9,7 +9,9 @@
 
 using namespace Luau;
 
+LUAU_FASTFLAG(LuauClipNestedAndRecursiveUnion)
 LUAU_FASTINT(LuauTypeInferRecursionLimit)
+LUAU_FASTFLAG(LuauPreventReentrantTypeFunctionReduction)
 LUAU_FASTFLAG(LuauDontForgetToReduceUnionFunc)
 
 TEST_SUITE_BEGIN("DefinitionTests");
@@ -543,6 +545,8 @@ TEST_CASE_FIXTURE(Fixture, "definition_file_has_source_module_name_set")
 
 TEST_CASE_FIXTURE(Fixture, "recursive_redefinition_reduces_rightfully")
 {
+    ScopedFastFlag _{FFlag::LuauClipNestedAndRecursiveUnion, true};
+
     LUAU_REQUIRE_NO_ERRORS(check(R"(
         local t: {[string]: string} = {}
 
@@ -588,6 +592,7 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "cli_142285_reduce_minted_union_func")
 
 TEST_CASE_FIXTURE(Fixture, "vector3_overflow")
 {
+    ScopedFastFlag _{FFlag::LuauPreventReentrantTypeFunctionReduction, true};
     // We set this to zero to ensure that we either run to completion or stack overflow here.
     ScopedFastInt sfi{FInt::LuauTypeInferRecursionLimit, 0};
 

tests/TypeInfer.functions.test.cpp

@@ -22,9 +22,8 @@ LUAU_FASTFLAG(LuauInstantiateInSubtyping)
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTINT(LuauTarjanChildLimit)
 LUAU_FASTFLAG(DebugLuauEqSatSimplification)
+LUAU_FASTFLAG(LuauSubtypingFixTailPack)
 LUAU_FASTFLAG(LuauUngeneralizedTypesForRecursiveFunctions)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
-LUAU_FASTFLAG(LuauReduceUnionFollowUnionType)
 
 TEST_SUITE_BEGIN("TypeInferFunctions");
 
@@ -1307,16 +1306,7 @@ f(function(a, b, c, ...) return a + b end)
     LUAU_REQUIRE_ERRORS(result);
 
     std::string expected;
-    if (FFlag::LuauInstantiateInSubtyping && FFlag::LuauImproveTypePathsInErrors)
-    {
-        expected = "Type\n\t"
-                   "'<a>(number, number, a) -> number'"
-                   "\ncould not be converted into\n\t"
-                   "'(number, number) -> number'"
-                   "\ncaused by:\n"
-                   "  Argument count mismatch. Function expects 3 arguments, but only 2 are specified";
-    }
-    else if (FFlag::LuauInstantiateInSubtyping)
+    if (FFlag::LuauInstantiateInSubtyping)
     {
         expected = R"(Type
     '<a>(number, number, a) -> number'
@@ -1325,15 +1315,6 @@ could not be converted into
 caused by:
   Argument count mismatch. Function expects 3 arguments, but only 2 are specified)";
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        expected = "Type\n\t"
-                   "'(number, number, *error-type*) -> number'"
-                   "\ncould not be converted into\n\t"
-                   "'(number, number) -> number'"
-                   "\ncaused by:\n"
-                   "  Argument count mismatch. Function expects 3 arguments, but only 2 are specified";
-    }
     else
     {
         expected = R"(Type
@@ -1538,14 +1519,7 @@ local b: B = a
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-    const std::string expected = (FFlag::LuauImproveTypePathsInErrors)
-                                     ? "Type\n\t"
-                                       "'(number, number) -> string'"
-                                       "\ncould not be converted into\n\t"
-                                       "'(number) -> string'"
-                                       "\ncaused by:\n"
-                                       "  Argument count mismatch. Function expects 2 arguments, but only 1 is specified"
-                                     : R"(Type
+    const std::string expected = R"(Type
     '(number, number) -> string'
 could not be converted into
     '(number) -> string'
@@ -1568,14 +1542,7 @@ local b: B = a
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-    const std::string expected = (FFlag::LuauImproveTypePathsInErrors) ? "Type\n\t"
-                                                                         "'(number, number) -> string'"
-                                                                         "\ncould not be converted into\n\t"
-                                                                         "'(number, string) -> string'"
-                                                                         "\ncaused by:\n"
-                                                                         "  Argument #2 type is not compatible.\n"
-                                                                         "Type 'string' could not be converted into 'number'"
-                                                                       : R"(Type
+    const std::string expected = R"(Type
     '(number, number) -> string'
 could not be converted into
     '(number, string) -> string'
@@ -1599,13 +1566,7 @@ local b: B = a
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-    const std::string expected = (FFlag::LuauImproveTypePathsInErrors) ? "Type\n\t"
-                                                                         "'(number, number) -> number'"
-                                                                         "\ncould not be converted into\n\t"
-                                                                         "'(number, number) -> (number, boolean)'"
-                                                                         "\ncaused by:\n"
-                                                                         "  Function only returns 1 value, but 2 are required here"
-                                                                       : R"(Type
+    const std::string expected = R"(Type
     '(number, number) -> number'
 could not be converted into
     '(number, number) -> (number, boolean)'
@@ -1628,14 +1589,7 @@ local b: B = a
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-    const std::string expected = (FFlag::LuauImproveTypePathsInErrors) ? "Type\n\t"
-                                                                         "'(number, number) -> string'"
-                                                                         "\ncould not be converted into\n\t"
-                                                                         "'(number, number) -> number'"
-                                                                         "\ncaused by:\n"
-                                                                         "  Return type is not compatible.\n"
-                                                                         "Type 'string' could not be converted into 'number'"
-                                                                       : R"(Type
+    const std::string expected = R"(Type
     '(number, number) -> string'
 could not be converted into
     '(number, number) -> number'
@@ -1659,14 +1613,7 @@ local b: B = a
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-    const std::string expected = (FFlag::LuauImproveTypePathsInErrors) ? "Type\n\t"
-                                                                         "'(number, number) -> (number, string)'"
-                                                                         "\ncould not be converted into\n\t"
-                                                                         "'(number, number) -> (number, boolean)'"
-                                                                         "\ncaused by:\n"
-                                                                         "  Return #2 type is not compatible.\n"
-                                                                         "Type 'string' could not be converted into 'boolean'"
-                                                                       : R"(Type
+    const std::string expected = R"(Type
     '(number, number) -> (number, string)'
 could not be converted into
     '(number, number) -> (number, boolean)'
@@ -1822,24 +1769,6 @@ end
             R"(Type function instance add<a, number> depends on generic function parameters but does not appear in the function signature; this construct cannot be type-checked at this time)"
         );
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(2, result);
-        CHECK_EQ(toString(result.errors[0]), R"(Type
-	'(string) -> string'
-could not be converted into
-	'((number) -> number)?'
-caused by:
-  None of the union options are compatible. For example:
-Type
-	'(string) -> string'
-could not be converted into
-	'(number) -> number'
-caused by:
-  Argument #1 type is not compatible.
-Type 'number' could not be converted into 'string')");
-        CHECK_EQ(toString(result.errors[1]), R"(Type 'string' could not be converted into 'number')");
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(2, result);
@@ -1883,31 +1812,15 @@ function t:b() return 2 end -- not OK
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        CHECK_EQ(
-            "Type\n\t"
-            "'(*error-type*) -> number'"
-            "\ncould not be converted into\n\t"
-            "'() -> number'\n"
-            "caused by:\n"
-            "  Argument count mismatch. Function expects 1 argument, but none are specified",
-            toString(result.errors[0])
-        );
-    }
-    else
-    {
-        CHECK_EQ(
-            R"(Type
+    CHECK_EQ(
+        R"(Type
     '(*error-type*) -> number'
 could not be converted into
     '() -> number'
 caused by:
   Argument count mismatch. Function expects 1 argument, but none are specified)",
-            toString(result.errors[0])
-        );
-    }
+        toString(result.errors[0])
+    );
 }
 
 TEST_CASE_FIXTURE(Fixture, "too_few_arguments_variadic")
@@ -2165,13 +2078,7 @@ z = y -- Not OK, so the line is colorable
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-    const std::string expected =
-        (FFlag::LuauImproveTypePathsInErrors)
-            ? "Type\n\t"
-              R"('(("blue" | "red") -> ("blue" | "red") -> ("blue" | "red") -> boolean) & (("blue" | "red") -> ("blue") -> ("blue") -> false) & (("blue" | "red") -> ("red") -> ("red") -> false) & (("blue") -> ("blue") -> ("blue" | "red") -> false) & (("red") -> ("red") -> ("blue" | "red") -> false)')"
-              "\ncould not be converted into\n\t"
-              R"('("blue" | "red") -> ("blue" | "red") -> ("blue" | "red") -> false'; none of the intersection parts are compatible)"
-            : R"(Type
+    const std::string expected = R"(Type
     '(("blue" | "red") -> ("blue" | "red") -> ("blue" | "red") -> boolean) & (("blue" | "red") -> ("blue") -> ("blue") -> false) & (("blue" | "red") -> ("red") -> ("red") -> false) & (("blue") -> ("blue") -> ("blue" | "red") -> false) & (("red") -> ("red") -> ("blue" | "red") -> false)'
 could not be converted into
     '("blue" | "red") -> ("blue" | "red") -> ("blue" | "red") -> false'; none of the intersection parts are compatible)";
@@ -2505,14 +2412,7 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "num_is_solved_before_num_or_str")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-        CHECK(
-            "Type pack 'string' could not be converted into 'number'; \n"
-            "this is because the 1st entry in the type pack is `string` in the former type and `number` in the latter type, and `string` is not a "
-            "subtype of `number`" == toString(result.errors.at(0))
-        );
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
         CHECK(toString(result.errors.at(0)) == "Type pack 'string' could not be converted into 'number'; at [0], string is not a subtype of number");
     else
         CHECK_EQ("Type 'string' could not be converted into 'number'", toString(result.errors[0]));
@@ -2537,13 +2437,7 @@ TEST_CASE_FIXTURE(BuiltinsFixture, "num_is_solved_after_num_or_str")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-        CHECK(
-            "Type pack 'string' could not be converted into 'number'; \n"
-            "this is because the 1st entry in the type pack is `string` in the former type and `number` in the latter type, and `string` is not a "
-            "subtype of `number`" == toString(result.errors.at(0))
-        );
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
         CHECK(toString(result.errors.at(0)) == "Type pack 'string' could not be converted into 'number'; at [0], string is not a subtype of number");
     else
         CHECK_EQ("Type 'string' could not be converted into 'number'", toString(result.errors[0]));
@@ -3139,6 +3033,8 @@ TEST_CASE_FIXTURE(Fixture, "hidden_variadics_should_not_break_subtyping")
 
 TEST_CASE_FIXTURE(BuiltinsFixture, "coroutine_wrap_result_call")
 {
+    ScopedFastFlag luauSubtypingFixTailPack{FFlag::LuauSubtypingFixTailPack, true};
+
     CheckResult result = check(R"(
         function foo(a, b)
             coroutine.wrap(a)(b)
@@ -3192,30 +3088,4 @@ TEST_CASE_FIXTURE(Fixture, "recursive_function_calls_should_not_use_the_generali
     LUAU_REQUIRE_NO_ERRORS(result);
 }
 
-TEST_CASE_FIXTURE(Fixture, "fuzz_unwind_mutually_recursive_union_type_func")
-{
-    ScopedFastFlag sffs[] = {
-        {FFlag::LuauSolverV2, true},
-        {FFlag::LuauReduceUnionFollowUnionType, true}
-    };
-
-    // This block ends up minting a type like:
-    //
-    //  t2 where t1 = union<t2, t1> | union<t2, t1> | union<t2, t1> ; t2 = union<t2, t1>
-    //
-    CheckResult result = check(R"(
-        local _ = ...
-        function _()
-            _ = _
-        end
-        _[function(...) repeat until _(_[l100]) _ = _ end] += _
-    )");
-    LUAU_REQUIRE_ERROR_COUNT(2, result);
-    auto err0 = get<UnknownSymbol>(result.errors[0]);
-    CHECK(err0);
-    CHECK_EQ(err0->name, "l100");
-    auto err1 = get<NotATable>(result.errors[1]);
-    CHECK(err1);
-}
-
 TEST_SUITE_END();

tests/TypeInfer.generics.test.cpp

@@ -10,9 +10,9 @@
 #include "ScopedFlags.h"
 #include "doctest.h"
 
-LUAU_FASTFLAG(LuauInstantiateInSubtyping)
-LUAU_FASTFLAG(LuauSolverV2)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
+LUAU_FASTFLAG(LuauInstantiateInSubtyping);
+LUAU_FASTFLAG(LuauSolverV2);
+LUAU_FASTFLAG(LuauDeferBidirectionalInferenceForTableAssignment)
 
 using namespace Luau;
 
@@ -855,6 +855,8 @@ end
 
 TEST_CASE_FIXTURE(Fixture, "generic_functions_should_be_memory_safe")
 {
+    ScopedFastFlag _{FFlag::LuauDeferBidirectionalInferenceForTableAssignment, true};
+
     CheckResult result = check(R"(
 --!strict
 -- At one point this produced a UAF
@@ -873,13 +875,7 @@ y.a.c = y
         CHECK(mismatch);
         CHECK_EQ(toString(mismatch->givenType), "{ a: { c: T<string>?, d: number }, b: number }");
         CHECK_EQ(toString(mismatch->wantedType), "T<string>");
-        std::string reason =
-            (FFlag::LuauImproveTypePathsInErrors)
-                ? "\nthis is because \n\t"
-                  " * accessing `a.d` results in `number` in the former type and `string` in the latter type, and `number` is not exactly "
-                  "`string`\n\t"
-                  " * accessing `b` results in `number` in the former type and `string` in the latter type, and `number` is not exactly `string`"
-                : "at [read \"a\"][read \"d\"], number is not exactly string\n\tat [read \"b\"], number is not exactly string";
+        std::string reason = "at [read \"a\"][read \"d\"], number is not exactly string\n\tat [read \"b\"], number is not exactly string";
         CHECK_EQ(mismatch->reason, reason);
     }
     else

tests/TypeInfer.intersectionTypes.test.cpp

@@ -9,8 +9,7 @@
 
 using namespace Luau;
 
-LUAU_FASTFLAG(LuauSolverV2)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
+LUAU_FASTFLAG(LuauSolverV2);
 
 TEST_SUITE_BEGIN("IntersectionTypes");
 
@@ -358,21 +357,12 @@ TEST_CASE_FIXTURE(Fixture, "table_intersection_write_sealed_indirect")
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(4, result);
-
-        const std::string expected = (FFlag::LuauImproveTypePathsInErrors)
-                                         ? "Type\n\t"
-                                           "'(string, number) -> string'"
-                                           "\ncould not be converted into\n\t"
-                                           "'(string) -> string'\n"
-                                           "caused by:\n"
-                                           "  Argument count mismatch. Function expects 2 arguments, but only 1 is specified"
-                                         : R"(Type
+        const std::string expected = R"(Type
     '(string, number) -> string'
 could not be converted into
     '(string) -> string'
 caused by:
   Argument count mismatch. Function expects 2 arguments, but only 1 is specified)";
-
         CHECK_EQ(expected, toString(result.errors[0]));
         CHECK_EQ(toString(result.errors[1]), "Cannot add property 'z' to table 'X & Y'");
         CHECK_EQ(toString(result.errors[2]), "Type 'number' could not be converted into 'string'");
@@ -397,14 +387,7 @@ TEST_CASE_FIXTURE(Fixture, "table_write_sealed_indirect")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(4, result);
-    const std::string expected = (FFlag::LuauImproveTypePathsInErrors)
-                                     ? "Type\n\t"
-                                       "'(string, number) -> string'"
-                                       "\ncould not be converted into\n\t"
-                                       "'(string) -> string'\n"
-                                       "caused by:\n"
-                                       "  Argument count mismatch. Function expects 2 arguments, but only 1 is specified"
-                                     : R"(Type
+    const std::string expected = R"(Type
     '(string, number) -> string'
 could not be converted into
     '(string) -> string'
@@ -447,20 +430,7 @@ Type 'number' could not be converted into 'X')";
         R"(Type 'number' could not be converted into 'X & Y & Z'; type number (number) is not a subtype of X & Y & Z[0] (X)
 	type number (number) is not a subtype of X & Y & Z[1] (Y)
 	type number (number) is not a subtype of X & Y & Z[2] (Z))";
-
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type "
-                                     "'number'"
-                                     " could not be converted into "
-                                     "'X & Y & Z'; \n"
-                                     "this is because \n\t"
-                                     " * the 1st component of the intersection is `X`, and `number` is not a subtype of `X`\n\t"
-                                     " * the 2nd component of the intersection is `Y`, and `number` is not a subtype of `Y`\n\t"
-                                     " * the 3rd component of the intersection is `Z`, and `number` is not a subtype of `Z`";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
         CHECK_EQ(dcrExprected, toString(result.errors[0]));
     else
         CHECK_EQ(expected, toString(result.errors[0]));
@@ -480,23 +450,7 @@ end
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type pack "
-                                     "'X & Y & Z'"
-                                     " could not be converted into "
-                                     "'number'; \n"
-                                     "this is because \n\t"
-                                     " * in the 1st entry in the type pack has the 1st component of the intersection as `X` and the 1st entry in the "
-                                     "type pack is `number`, and `X` is not a subtype of `number`\n\t"
-                                     " * in the 1st entry in the type pack has the 2nd component of the intersection as `Y` and the 1st entry in the "
-                                     "type pack is `number`, and `Y` is not a subtype of `number`\n\t"
-                                     " * in the 1st entry in the type pack has the 3rd component of the intersection as `Z` and the 1st entry in the "
-                                     "type pack is `number`, and `Z` is not a subtype of `number`";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         CHECK_EQ(
             R"(Type pack 'X & Y & Z' could not be converted into 'number'; type X & Y & Z[0][0] (X) is not a subtype of number[0] (number)
@@ -549,19 +503,7 @@ TEST_CASE_FIXTURE(Fixture, "intersect_bool_and_false")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type "
-                                     "'boolean & false'"
-                                     " could not be converted into "
-                                     "'true'; \n"
-                                     "this is because \n\t"
-                                     " * the 1st component of the intersection is `boolean`, which is not a subtype of `true`\n\t"
-                                     " * the 2nd component of the intersection is `false`, which is not a subtype of `true`";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         CHECK_EQ(
             R"(Type 'boolean & false' could not be converted into 'true'; type boolean & false[0] (boolean) is not a subtype of true (true)
@@ -585,21 +527,8 @@ TEST_CASE_FIXTURE(Fixture, "intersect_false_and_bool_and_false")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
     // TODO: odd stringification of `false & (boolean & false)`.)
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type "
-                                     "'boolean & false & false'"
-                                     " could not be converted into "
-                                     "'true'; \n"
-                                     "this is because \n\t"
-                                     " * the 1st component of the intersection is `false`, which is not a subtype of `true`\n\t"
-                                     " * the 2nd component of the intersection is `boolean`, which is not a subtype of `true`\n\t"
-                                     " * the 3rd component of the intersection is `false`, which is not a subtype of `true`";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
         CHECK_EQ(
             R"(Type 'boolean & false & false' could not be converted into 'true'; type boolean & false & false[0] (false) is not a subtype of true (true)
 	type boolean & false & false[1] (boolean) is not a subtype of true (true)
@@ -621,39 +550,7 @@ TEST_CASE_FIXTURE(Fixture, "intersect_saturate_overloaded_functions")
             local z : (number) -> number = x -- Not OK
         end
     )");
-
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected1 =
-            "Type\n\t"
-            "'((number?) -> number?) & ((string?) -> string?)'"
-            "\ncould not be converted into\n\t"
-            "'(nil) -> nil'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `number` and it returns the 1st entry in the type pack is `nil`, and `number` is not a subtype of `nil`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `string` and it returns the 1st entry in the type pack is `nil`, and `string` is not a subtype of `nil`";
-
-        const std::string expected2 =
-            "Type\n\t"
-            "'((number?) -> number?) & ((string?) -> string?)'"
-            "\ncould not be converted into\n\t"
-            "'(number) -> number'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 2nd component of the "
-            "union as `nil` and it returns the 1st entry in the type pack is `number`, and `nil` is not a subtype of `number`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `string` and it returns the 1st entry in the type pack is `number`, and `string` is not a subtype of `number`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 2nd component of the "
-            "union as `nil` and it returns the 1st entry in the type pack is `number`, and `nil` is not a subtype of `number`\n\t"
-            " * in the 2nd component of the intersection, the function takes the 1st entry in the type pack which is `string?` and it takes the 1st "
-            "entry in the type pack is `number`, and `string?` is not a supertype of `number`";
-
-        CHECK_EQ(expected1, toString(result.errors[0]));
-        CHECK_EQ(expected2, toString(result.errors[1]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         LUAU_REQUIRE_ERROR_COUNT(2, result);
         const std::string expected1 = R"(Type
@@ -671,15 +568,6 @@ could not be converted into
         CHECK_EQ(expected1, toString(result.errors[0]));
         CHECK_EQ(expected2, toString(result.errors[1]));
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(1, result);
-        const std::string expected = R"(Type
-	'((number?) -> number?) & ((string?) -> string?)'
-could not be converted into
-	'(number) -> number'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
@@ -704,23 +592,11 @@ TEST_CASE_FIXTURE(Fixture, "union_saturate_overloaded_functions")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type\n\t"
-                                     "'((number) -> number) & ((string) -> string)'"
-                                     "\ncould not be converted into\n\t"
-                                     "'(boolean | number) -> boolean | number'; none of the intersection parts are compatible";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else
-    {
-        const std::string expected = R"(Type
+    const std::string expected = R"(Type
     '((number) -> number) & ((string) -> string)'
 could not be converted into
     '(boolean | number) -> boolean | number'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
+    CHECK_EQ(expected, toString(result.errors[0]));
 }
 
 TEST_CASE_FIXTURE(Fixture, "intersection_of_tables")
@@ -733,42 +609,16 @@ TEST_CASE_FIXTURE(Fixture, "intersection_of_tables")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type "
-                                     "'{ p: number?, q: number?, r: number? } & { p: number?, q: string? }'"
-                                     " could not be converted into "
-                                     "'{ p: nil }'; \n"
-                                     "this is because \n\t"
-                                     " * in the 1st component of the intersection, accessing `p` has the 1st component of the union as `number` and "
-                                     "accessing `p` results in `nil`, and `number` is not exactly `nil`\n\t"
-                                     " * in the 2nd component of the intersection, accessing `p` has the 1st component of the union as `number` and "
-                                     "accessing `p` results in `nil`, and `number` is not exactly `nil`";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected =
-            R"(Type
-	'{| p: number?, q: number?, r: number? |} & {| p: number?, q: string? |}'
-could not be converted into
-	'{| p: nil |}'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else
-    {
-        const std::string expected =
-            (FFlag::LuauSolverV2)
-                ? R"(Type '{ p: number?, q: number?, r: number? } & { p: number?, q: string? }' could not be converted into '{ p: nil }'; type { p: number?, q: number?, r: number? } & { p: number?, q: string? }[0][read "p"][0] (number) is not exactly { p: nil }[read "p"] (nil)
+    const std::string expected =
+        (FFlag::LuauSolverV2)
+            ? R"(Type '{ p: number?, q: number?, r: number? } & { p: number?, q: string? }' could not be converted into '{ p: nil }'; type { p: number?, q: number?, r: number? } & { p: number?, q: string? }[0][read "p"][0] (number) is not exactly { p: nil }[read "p"] (nil)
 	type { p: number?, q: number?, r: number? } & { p: number?, q: string? }[1][read "p"][0] (number) is not exactly { p: nil }[read "p"] (nil))"
-                :
-                R"(Type
+            :
+            R"(Type
     '{| p: number?, q: number?, r: number? |} & {| p: number?, q: string? |}'
 could not be converted into
     '{| p: nil |}'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
+    CHECK_EQ(expected, toString(result.errors[0]));
 }
 
 TEST_CASE_FIXTURE(Fixture, "intersection_of_tables_with_top_properties")
@@ -780,28 +630,7 @@ TEST_CASE_FIXTURE(Fixture, "intersection_of_tables_with_top_properties")
         end
     )");
 
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type\n\t"
-                                     "'{ p: number?, q: any } & { p: unknown, q: string? }'"
-                                     "\ncould not be converted into\n\t"
-                                     "'{ p: string?, q: number? }'; \n"
-                                     "this is because \n\t"
-                                     " * in the 1st component of the intersection, accessing `p` has the 1st component of the union as `number` and "
-                                     "accessing `p` results in `string?`, and `number` is not exactly `string?`\n\t"
-                                     " * in the 1st component of the intersection, accessing `p` results in `number?` and accessing `p` has the 1st "
-                                     "component of the union as `string`, and `number?` is not exactly `string`\n\t"
-                                     " * in the 1st component of the intersection, accessing `q` results in `any` and accessing `q` results in "
-                                     "`number?`, and `any` is not exactly `number?`\n\t"
-                                     " * in the 2nd component of the intersection, accessing `p` results in `unknown` and accessing `p` results in "
-                                     "`string?`, and `unknown` is not exactly `string?`\n\t"
-                                     " * in the 2nd component of the intersection, accessing `q` has the 1st component of the union as `string` and "
-                                     "accessing `q` results in `number?`, and `string` is not exactly `number?`\n\t"
-                                     " * in the 2nd component of the intersection, accessing `q` results in `string?` and accessing `q` has the 1st "
-                                     "component of the union as `number`, and `string?` is not exactly `number`";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
         CHECK_EQ(
@@ -817,15 +646,6 @@ could not be converted into
             toString(result.errors[0])
         );
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(1, result);
-        const std::string expected = R"(Type
-	'{| p: number?, q: any |} & {| p: unknown, q: string? |}'
-could not be converted into
-	'{| p: string?, q: number? |}'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
@@ -858,52 +678,7 @@ TEST_CASE_FIXTURE(Fixture, "overloaded_functions_returning_intersections")
         end
     )");
 
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected1 =
-            "Type\n\t"
-            "'((number?) -> { p: number } & { q: number }) & ((string?) -> { p: number } & { r: number })'"
-            "\ncould not be converted into\n\t"
-            "'(nil) -> { p: number, q: number, r: number }'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "intersection as `{ p: number }` and it returns the 1st entry in the type pack is `{ p: number, q: number, r: number }`, and `{ p: "
-            "number }` is not a subtype of `{ p: number, q: number, r: number }`\n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 2nd component of the "
-            "intersection as `{ q: number }` and it returns the 1st entry in the type pack is `{ p: number, q: number, r: number }`, and `{ q: "
-            "number }` is not a subtype of `{ p: number, q: number, r: number }`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "intersection as `{ p: number }` and it returns the 1st entry in the type pack is `{ p: number, q: number, r: number }`, and `{ p: "
-            "number }` is not a subtype of `{ p: number, q: number, r: number }`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 2nd component of the "
-            "intersection as `{ r: number }` and it returns the 1st entry in the type pack is `{ p: number, q: number, r: number }`, and `{ r: "
-            "number }` is not a subtype of `{ p: number, q: number, r: number }`";
-
-        const std::string expected2 =
-            "Type\n\t"
-            "'((number?) -> { p: number } & { q: number }) & ((string?) -> { p: number } & { r: number })'"
-            "\ncould not be converted into\n\t"
-            "'(number?) -> { p: number, q: number, r: number }'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "intersection as `{ p: number }` and it returns the 1st entry in the type pack is `{ p: number, q: number, r: number }`, and `{ p: "
-            "number }` is not a subtype of `{ p: number, q: number, r: number }`\n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 2nd component of the "
-            "intersection as `{ q: number }` and it returns the 1st entry in the type pack is `{ p: number, q: number, r: number }`, and `{ q: "
-            "number }` is not a subtype of `{ p: number, q: number, r: number }`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "intersection as `{ p: number }` and it returns the 1st entry in the type pack is `{ p: number, q: number, r: number }`, and `{ p: "
-            "number }` is not a subtype of `{ p: number, q: number, r: number }`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 2nd component of the "
-            "intersection as `{ r: number }` and it returns the 1st entry in the type pack is `{ p: number, q: number, r: number }`, and `{ r: "
-            "number }` is not a subtype of `{ p: number, q: number, r: number }`\n\t"
-            " * in the 2nd component of the intersection, the function takes the 1st entry in the type pack which is `string?` and it takes the 1st "
-            "entry in the type pack has the 1st component of the union as `number`, and `string?` is not a supertype of `number`";
-
-        CHECK_EQ(expected1, toString(result.errors[0]));
-        CHECK_EQ(expected2, toString(result.errors[1]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         LUAU_REQUIRE_ERROR_COUNT(2, result);
         CHECK_EQ(
@@ -928,17 +703,6 @@ could not be converted into
             toString(result.errors[1])
         );
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(1, result);
-        CHECK_EQ(
-            R"(Type
-	'((number?) -> {| p: number |} & {| q: number |}) & ((string?) -> {| p: number |} & {| r: number |})'
-could not be converted into
-	'(number?) -> {| p: number, q: number, r: number |}'; none of the intersection parts are compatible)",
-            toString(result.errors[0])
-        );
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
@@ -966,15 +730,6 @@ TEST_CASE_FIXTURE(Fixture, "overloaded_functions_mentioning_generic")
     {
         LUAU_REQUIRE_ERROR_COUNT(0, result);
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(1, result);
-        const std::string expected = R"(Type
-	'((number?) -> a | number) & ((string?) -> a | string)'
-could not be converted into
-	'(number?) -> a'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
@@ -1002,15 +757,6 @@ TEST_CASE_FIXTURE(Fixture, "overloaded_functions_mentioning_generics")
     {
         LUAU_REQUIRE_NO_ERRORS(result);
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(1, result);
-        const std::string expected = R"(Type
-	'((a?) -> a | b) & ((c?) -> b | c)'
-could not be converted into
-	'(a?) -> (a & c) | b'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
@@ -1032,35 +778,7 @@ TEST_CASE_FIXTURE(Fixture, "overloaded_functions_mentioning_generic_packs")
             end
         end
     )");
-
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected1 =
-            "Type\n\t"
-            "'((number?, a...) -> (number?, b...)) & ((string?, a...) -> (string?, b...))'"
-            "\ncould not be converted into\n\t"
-            "'(nil, a...) -> (nil, b...)'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `number` and it returns the 1st entry in the type pack is `nil`, and `number` is not a subtype of `nil`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `string` and it returns the 1st entry in the type pack is `nil`, and `string` is not a subtype of `nil`";
-
-        const std::string expected2 =
-            "Type\n\t"
-            "'((number?, a...) -> (number?, b...)) & ((string?, a...) -> (string?, b...))'"
-            "\ncould not be converted into\n\t"
-            "'(nil, b...) -> (nil, a...)'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `number` and it returns the 1st entry in the type pack is `nil`, and `number` is not a subtype of `nil`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `string` and it returns the 1st entry in the type pack is `nil`, and `string` is not a subtype of `nil`";
-
-        CHECK_EQ(expected1, toString(result.errors[0]));
-        CHECK_EQ(expected2, toString(result.errors[1]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         LUAU_REQUIRE_ERROR_COUNT(2, result);
         CHECK_EQ(
@@ -1080,15 +798,6 @@ could not be converted into
             toString(result.errors[1])
         );
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(1, result);
-        const std::string expected = R"(Type
-	'((number?, a...) -> (number?, b...)) & ((string?, a...) -> (string?, b...))'
-could not be converted into
-	'(nil, b...) -> (nil, a...)'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
@@ -1115,23 +824,11 @@ TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_unknown_result")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type\n\t"
-                                     "'((nil) -> unknown) & ((number) -> number)'"
-                                     "\ncould not be converted into\n\t"
-                                     "'(number?) -> number?'; none of the intersection parts are compatible";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else
-    {
-        const std::string expected = R"(Type
+    const std::string expected = R"(Type
     '((nil) -> unknown) & ((number) -> number)'
 could not be converted into
     '(number?) -> number?'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
+    CHECK_EQ(expected, toString(result.errors[0]));
 }
 
 TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_unknown_arguments")
@@ -1149,23 +846,11 @@ TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_unknown_arguments")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type\n\t"
-                                     "'((number) -> number?) & ((unknown) -> string?)'"
-                                     "\ncould not be converted into\n\t"
-                                     "'(number?) -> nil'; none of the intersection parts are compatible";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
-    else
-    {
-        const std::string expected = R"(Type
+    const std::string expected = R"(Type
     '((number) -> number?) & ((unknown) -> string?)'
 could not be converted into
     '(number?) -> nil'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
+    CHECK_EQ(expected, toString(result.errors[0]));
 }
 
 TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_never_result")
@@ -1179,36 +864,7 @@ TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_never_result")
     end
     )");
 
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected1 =
-            "Type\n\t"
-            "'((nil) -> never) & ((number) -> number)'"
-            "\ncould not be converted into\n\t"
-            "'(number?) -> number'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function takes the 1st entry in the type pack which is `number` and it takes the 1st "
-            "entry in the type pack has the 2nd component of the union as `nil`, and `number` is not a supertype of `nil`\n\t"
-            " * in the 2nd component of the intersection, the function takes the 1st entry in the type pack which is `nil` and it takes the 1st "
-            "entry in the type pack has the 1st component of the union as `number`, and `nil` is not a supertype of `number`";
-
-        const std::string expected2 =
-            "Type\n\t"
-            "'((nil) -> never) & ((number) -> number)'"
-            "\ncould not be converted into\n\t"
-            "'(number?) -> never'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which is `number` and it returns the "
-            "1st entry in the type pack is `never`, and `number` is not a subtype of `never`\n\t"
-            " * in the 1st component of the intersection, the function takes the 1st entry in the type pack which is `number` and it takes the 1st "
-            "entry in the type pack has the 2nd component of the union as `nil`, and `number` is not a supertype of `nil`\n\t"
-            " * in the 2nd component of the intersection, the function takes the 1st entry in the type pack which is `nil` and it takes the 1st "
-            "entry in the type pack has the 1st component of the union as `number`, and `nil` is not a supertype of `number`";
-
-        CHECK_EQ(expected1, toString(result.errors[0]));
-        CHECK_EQ(expected2, toString(result.errors[1]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         LUAU_REQUIRE_ERROR_COUNT(2, result);
         CHECK_EQ(
@@ -1229,15 +885,6 @@ could not be converted into
             toString(result.errors[1])
         );
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(1, result);
-        const std::string expected = R"(Type
-	'((nil) -> never) & ((number) -> number)'
-could not be converted into
-	'(number?) -> never'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
@@ -1260,40 +907,7 @@ TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_never_arguments")
         end
     )");
 
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected1 =
-            "Type\n\t"
-            "'((never) -> string?) & ((number) -> number?)'"
-            "\ncould not be converted into\n\t"
-            "'(never) -> nil'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `number` and it returns the 1st entry in the type pack is `nil`, and `number` is not a subtype of `nil`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `string` and it returns the 1st entry in the type pack is `nil`, and `string` is not a subtype of `nil`";
-
-        const std::string expected2 =
-            "Type\n\t"
-            "'((never) -> string?) & ((number) -> number?)'"
-            "\ncould not be converted into\n\t"
-            "'(number?) -> nil'; \n"
-            "this is because \n\t"
-            " * in the 1st component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `number` and it returns the 1st entry in the type pack is `nil`, and `number` is not a subtype of `nil`\n\t"
-            " * in the 1st component of the intersection, the function takes the 1st entry in the type pack which is `number` and it takes the 1st "
-            "entry in the type pack has the 2nd component of the union as `nil`, and `number` is not a supertype of `nil`\n\t"
-            " * in the 2nd component of the intersection, the function returns the 1st entry in the type pack which has the 1st component of the "
-            "union as `string` and it returns the 1st entry in the type pack is `nil`, and `string` is not a subtype of `nil`\n\t"
-            " * in the 2nd component of the intersection, the function takes the 1st entry in the type pack which is `never` and it takes the 1st "
-            "entry in the type pack has the 1st component of the union as `number`, and `never` is not a supertype of `number`\n\t"
-            " * in the 2nd component of the intersection, the function takes the 1st entry in the type pack which is `never` and it takes the 1st "
-            "entry in the type pack has the 2nd component of the union as `nil`, and `never` is not a supertype of `nil`";
-
-        CHECK_EQ(expected1, toString(result.errors[0]));
-        CHECK_EQ(expected2, toString(result.errors[1]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         LUAU_REQUIRE_ERROR_COUNT(2, result);
         const std::string expected1 = R"(Type
@@ -1312,15 +926,6 @@ could not be converted into
         CHECK_EQ(expected1, toString(result.errors[0]));
         CHECK_EQ(expected2, toString(result.errors[1]));
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(1, result);
-        const std::string expected = R"(Type
-	'((never) -> string?) & ((number) -> number?)'
-could not be converted into
-	'(number?) -> nil'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
@@ -1345,23 +950,11 @@ TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_overlapping_results_and_
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type\n\t"
-                                     "'((number?) -> (...number)) & ((string?) -> number | string)'"
-                                     "\ncould not be converted into\n\t"
-                                     "'(number | string) -> (number, number?)'; none of the intersection parts are compatible";
-        CHECK(expected == toString(result.errors[0]));
-    }
-    else
-    {
-        const std::string expected = R"(Type
+    const std::string expected = R"(Type
     '((number?) -> (...number)) & ((string?) -> number | string)'
 could not be converted into
     '(number | string) -> (number, number?)'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
+    CHECK_EQ(expected, toString(result.errors[0]));
 }
 
 TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_weird_typepacks_1")
@@ -1429,15 +1022,6 @@ TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_weird_typepacks_3")
     {
         LUAU_REQUIRE_NO_ERRORS(result);
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        LUAU_REQUIRE_ERROR_COUNT(1, result);
-        const std::string expected = R"(Type
-	'(() -> (a...)) & (() -> (number?, a...))'
-could not be converted into
-	'() -> number'; none of the intersection parts are compatible)";
-        CHECK_EQ(expected, toString(result.errors[0]));
-    }
     else
     {
         LUAU_REQUIRE_ERROR_COUNT(1, result);
@@ -1461,21 +1045,7 @@ TEST_CASE_FIXTURE(Fixture, "overloadeded_functions_with_weird_typepacks_4")
     )");
 
     LUAU_REQUIRE_ERROR_COUNT(1, result);
-
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type\n\t"
-                                     "'((a...) -> ()) & ((number, a...) -> number)'"
-                                     "\ncould not be converted into\n\t"
-                                     "'((a...) -> ()) & ((number, a...) -> number)'; \n"
-                                     "this is because \n\t"
-                                     " * in the 1st component of the intersection, the function returns is `()` in the former type and `number` in "
-                                     "the latter type, and `()` is not a subtype of `number`\n\t"
-                                     " * in the 2nd component of the intersection, the function takes a tail of `a...` and in the 1st component of "
-                                     "the intersection, the function takes a tail of `a...`, and `a...` is not a supertype of `a...`";
-        CHECK(expected == toString(result.errors[0]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         CHECK_EQ(
             R"(Type
@@ -1486,16 +1056,6 @@ could not be converted into
             toString(result.errors[0])
         );
     }
-    else if (FFlag::LuauImproveTypePathsInErrors)
-    {
-        CHECK_EQ(
-            R"(Type
-	'((a...) -> ()) & ((number, a...) -> number)'
-could not be converted into
-	'(number?) -> ()'; none of the intersection parts are compatible)",
-            toString(result.errors[0])
-        );
-    }
     else
     {
         CHECK_EQ(

tests/TypeInfer.modules.test.cpp

@@ -12,7 +12,6 @@
 
 LUAU_FASTFLAG(LuauInstantiateInSubtyping)
 LUAU_FASTFLAG(LuauSolverV2)
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
 
 using namespace Luau;
 
@@ -462,14 +461,7 @@ local b: B.T = a
     CheckResult result = frontend.check("game/C");
     LUAU_REQUIRE_ERROR_COUNT(1, result);
 
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type 'T' from 'game/A' could not be converted into 'T' from 'game/B'; \n"
-                                     "this is because accessing `x` results in `number` in the former type and `string` in the latter type, and "
-                                     "`number` is not exactly `string`";
-        CHECK(expected == toString(result.errors[0]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         CHECK(
             toString(result.errors.at(0)) ==
@@ -515,14 +507,7 @@ local b: B.T = a
     CheckResult result = frontend.check("game/D");
     LUAU_REQUIRE_ERROR_COUNT(1, result);
 
-    if (FFlag::LuauSolverV2 && FFlag::LuauImproveTypePathsInErrors)
-    {
-        const std::string expected = "Type 'T' from 'game/B' could not be converted into 'T' from 'game/C'; \n"
-                                     "this is because accessing `x` results in `number` in the former type and `string` in the latter type, and "
-                                     "`number` is not exactly `string`";
-        CHECK(expected == toString(result.errors[0]));
-    }
-    else if (FFlag::LuauSolverV2)
+    if (FFlag::LuauSolverV2)
     {
         CHECK(
             toString(result.errors.at(0)) ==

tests/TypeInfer.negations.test.cpp

@@ -79,5 +79,4 @@ end
 )");
     LUAU_REQUIRE_NO_ERRORS(result);
 }
-
 TEST_SUITE_END();