luau/tests/TypeInfer.refinements.test.cpp
Andy Friesen 0b2755f964
Sync to upstream/release/589 (#1000)
* Progress toward a diffing algorithm for types. We hope that this will
be useful for writing clearer error messages.
* Add a missing recursion limiter in `Unifier::tryUnifyTables`. This was
causing a crash in certain situations.
* Luau heap graph enumeration improvements:
    * Weak references are not reported
    * Added tag as a fallback name of non-string table links
* Included top Luau function information in thread name to understand
where thread might be suspended
* Constant folding for `math.pi` and `math.huge` at -O2
* Optimize `string.format` and `%*`
* This change makes string interpolation 1.5x-2x faster depending on the
number and type of formatted components, assuming a few are using
primitive types, and reduces associated GC pressure.

New type checker:

* Initial work toward tracking the upper and lower bounds of types
accurately.

Native code generation (JIT):

* Add IrCmd::CHECK_TRUTHY for improved assert fast-calls
* Do not compute type map for modules without types
* Capture metatable+readonly state for NEW_TABLE IR instructions
* Replace JUMP_CMP_ANY with CMP_ANY and existing JUMP_EQ_INT
* Add support for exits to VM with reentry lock in VmExit

---------

Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
2023-08-04 12:18:54 -07:00

1924 lines
54 KiB
C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#include "Luau/Normalize.h"
#include "Luau/Scope.h"
#include "Luau/TypeInfer.h"
#include "Fixture.h"
#include "doctest.h"
LUAU_FASTFLAG(DebugLuauDeferredConstraintResolution)
using namespace Luau;
namespace
{
std::optional<WithPredicate<TypePackId>> magicFunctionInstanceIsA(
TypeChecker& typeChecker, const ScopePtr& scope, const AstExprCall& expr, WithPredicate<TypePackId> withPredicate)
{
if (expr.args.size != 1)
return std::nullopt;
auto index = expr.func->as<Luau::AstExprIndexName>();
auto str = expr.args.data[0]->as<Luau::AstExprConstantString>();
if (!index || !str)
return std::nullopt;
std::optional<LValue> lvalue = tryGetLValue(*index->expr);
std::optional<TypeFun> tfun = scope->lookupType(std::string(str->value.data, str->value.size));
if (!lvalue || !tfun)
return std::nullopt;
ModulePtr module = typeChecker.currentModule;
TypePackId booleanPack = module->internalTypes.addTypePack({typeChecker.booleanType});
return WithPredicate<TypePackId>{booleanPack, {IsAPredicate{std::move(*lvalue), expr.location, tfun->type}}};
}
void dcrMagicRefinementInstanceIsA(const MagicRefinementContext& ctx)
{
if (ctx.callSite->args.size != 1 || ctx.discriminantTypes.empty())
return;
auto index = ctx.callSite->func->as<Luau::AstExprIndexName>();
auto str = ctx.callSite->args.data[0]->as<Luau::AstExprConstantString>();
if (!index || !str)
return;
std::optional<TypeId> discriminantTy = ctx.discriminantTypes[0];
if (!discriminantTy)
return;
std::optional<TypeFun> tfun = ctx.scope->lookupType(std::string(str->value.data, str->value.size));
if (!tfun)
return;
LUAU_ASSERT(get<BlockedType>(*discriminantTy));
asMutable(*discriminantTy)->ty.emplace<BoundType>(tfun->type);
}
struct RefinementClassFixture : BuiltinsFixture
{
RefinementClassFixture()
{
TypeArena& arena = frontend.globals.globalTypes;
NotNull<Scope> scope{frontend.globals.globalScope.get()};
std::optional<TypeId> rootSuper = std::make_optional(builtinTypes->classType);
unfreeze(arena);
TypeId vec3 = arena.addType(ClassType{"Vector3", {}, rootSuper, std::nullopt, {}, nullptr, "Test"});
getMutable<ClassType>(vec3)->props = {
{"X", Property{builtinTypes->numberType}},
{"Y", Property{builtinTypes->numberType}},
{"Z", Property{builtinTypes->numberType}},
};
TypeId inst = arena.addType(ClassType{"Instance", {}, rootSuper, std::nullopt, {}, nullptr, "Test"});
TypePackId isAParams = arena.addTypePack({inst, builtinTypes->stringType});
TypePackId isARets = arena.addTypePack({builtinTypes->booleanType});
TypeId isA = arena.addType(FunctionType{isAParams, isARets});
getMutable<FunctionType>(isA)->magicFunction = magicFunctionInstanceIsA;
getMutable<FunctionType>(isA)->dcrMagicRefinement = dcrMagicRefinementInstanceIsA;
getMutable<ClassType>(inst)->props = {
{"Name", Property{builtinTypes->stringType}},
{"IsA", Property{isA}},
};
TypeId folder = frontend.globals.globalTypes.addType(ClassType{"Folder", {}, inst, std::nullopt, {}, nullptr, "Test"});
TypeId part = frontend.globals.globalTypes.addType(ClassType{"Part", {}, inst, std::nullopt, {}, nullptr, "Test"});
getMutable<ClassType>(part)->props = {
{"Position", Property{vec3}},
};
frontend.globals.globalScope->exportedTypeBindings["Vector3"] = TypeFun{{}, vec3};
frontend.globals.globalScope->exportedTypeBindings["Instance"] = TypeFun{{}, inst};
frontend.globals.globalScope->exportedTypeBindings["Folder"] = TypeFun{{}, folder};
frontend.globals.globalScope->exportedTypeBindings["Part"] = TypeFun{{}, part};
for (const auto& [name, ty] : frontend.globals.globalScope->exportedTypeBindings)
persist(ty.type);
freeze(frontend.globals.globalTypes);
}
};
} // namespace
TEST_SUITE_BEGIN("RefinementTest");
TEST_CASE_FIXTURE(Fixture, "is_truthy_constraint")
{
CheckResult result = check(R"(
function f(v: string?)
if v then
local s = v
else
local s = v
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("string", toString(requireTypeAtPosition({3, 26})));
CHECK_EQ("nil", toString(requireTypeAtPosition({5, 26})));
}
TEST_CASE_FIXTURE(Fixture, "invert_is_truthy_constraint")
{
CheckResult result = check(R"(
function f(v: string?)
if not v then
local s = v
else
local s = v
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({3, 26})));
CHECK_EQ("string", toString(requireTypeAtPosition({5, 26})));
}
TEST_CASE_FIXTURE(Fixture, "parenthesized_expressions_are_followed_through")
{
CheckResult result = check(R"(
function f(v: string?)
if (not v) then
local s = v
else
local s = v
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({3, 26})));
CHECK_EQ("string", toString(requireTypeAtPosition({5, 26})));
}
TEST_CASE_FIXTURE(Fixture, "and_constraint")
{
CheckResult result = check(R"(
function f(a: string?, b: number?)
if a and b then
local x = a
local y = b
else
local x = a
local y = b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("string", toString(requireTypeAtPosition({3, 26})));
CHECK_EQ("number", toString(requireTypeAtPosition({4, 26})));
CHECK_EQ("string?", toString(requireTypeAtPosition({6, 26})));
CHECK_EQ("number?", toString(requireTypeAtPosition({7, 26})));
}
TEST_CASE_FIXTURE(Fixture, "not_and_constraint")
{
CheckResult result = check(R"(
function f(a: string?, b: number?)
if not (a and b) then
local x = a
local y = b
else
local x = a
local y = b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("string?", toString(requireTypeAtPosition({3, 26})));
CHECK_EQ("number?", toString(requireTypeAtPosition({4, 26})));
CHECK_EQ("string", toString(requireTypeAtPosition({6, 26})));
CHECK_EQ("number", toString(requireTypeAtPosition({7, 26})));
}
TEST_CASE_FIXTURE(Fixture, "or_predicate_with_truthy_predicates")
{
CheckResult result = check(R"(
function f(a: string?, b: number?)
if a or b then
local x = a
local y = b
else
local x = a
local y = b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("string?", toString(requireTypeAtPosition({3, 26})));
CHECK_EQ("number?", toString(requireTypeAtPosition({4, 26})));
CHECK_EQ("nil", toString(requireTypeAtPosition({6, 26})));
CHECK_EQ("nil", toString(requireTypeAtPosition({7, 26})));
}
TEST_CASE_FIXTURE(Fixture, "a_and_b_or_a_and_c")
{
CheckResult result = check(R"(
function f(a: string?, b: number?, c: boolean)
if (a and b) or (a and c) then
local foo = a
local bar = b
local baz = c
else
local foo = a
local bar = b
local baz = c
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("string", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("number?", toString(requireTypeAtPosition({4, 28})));
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("boolean", toString(requireTypeAtPosition({5, 28})));
else
CHECK_EQ("true", toString(requireTypeAtPosition({5, 28}))); // oh no! :(
CHECK_EQ("string?", toString(requireTypeAtPosition({7, 28})));
CHECK_EQ("number?", toString(requireTypeAtPosition({8, 28})));
CHECK_EQ("boolean", toString(requireTypeAtPosition({9, 28})));
}
TEST_CASE_FIXTURE(Fixture, "type_assertion_expr_carry_its_constraints")
{
CheckResult result = check(R"(
function g(a: number?, b: string?)
if (a :: any) and (b :: any) then
local x = a
local y = b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ("number?", toString(requireTypeAtPosition({3, 26})));
CHECK_EQ("string?", toString(requireTypeAtPosition({4, 26})));
}
else
{
// We're going to drop support for type refinements through type assertions.
CHECK_EQ("number", toString(requireTypeAtPosition({3, 26})));
CHECK_EQ("string", toString(requireTypeAtPosition({4, 26})));
}
}
TEST_CASE_FIXTURE(BuiltinsFixture, "typeguard_in_if_condition_position")
{
CheckResult result1 = check(R"(
function f(s: any, t: unknown)
if type(s) == "number" then
local n = s
end
if type(t) == "number" then
local n = t
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result1);
// DCR changes refinements to preserve error suppression.
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("*error-type* | number", toString(requireTypeAtPosition({3, 26})));
else
CHECK_EQ("number", toString(requireTypeAtPosition({3, 26})));
CHECK_EQ("number", toString(requireTypeAtPosition({6, 26})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "typeguard_in_assert_position")
{
CheckResult result = check(R"(
local a
assert(type(a) == "number")
local b = a
)");
LUAU_REQUIRE_NO_ERRORS(result);
REQUIRE_EQ("number", toString(requireType("b")));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "call_an_incompatible_function_after_using_typeguard")
{
CheckResult result = check(R"(
local function f(x: number)
return x
end
local function g(x: unknown)
if type(x) == "string" then
f(x)
end
end
local function h(x: any)
if type(x) == "string" then
f(x)
end
end
)");
if (FFlag::DebugLuauDeferredConstraintResolution)
LUAU_REQUIRE_ERROR_COUNT(1, result);
else
LUAU_REQUIRE_ERROR_COUNT(2, result);
CHECK_EQ("Type 'string' could not be converted into 'number'", toString(result.errors[0]));
if (!FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("Type 'string' could not be converted into 'number'", toString(result.errors[1]));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "impossible_type_narrow_is_not_an_error")
{
// This unit test serves as a reminder to not implement this warning until Luau is intelligent enough.
// For instance, getting a value out of the indexer and checking whether the value exists is not an error.
CheckResult result = check(R"(
local t: {string} = {"a", "b", "c"}
local v = t[4]
if not v then
t[4] = "d"
else
print(v)
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(Fixture, "truthy_constraint_on_properties")
{
CheckResult result = check(R"(
local t: {x: number?} = {x = 1}
if t.x then
local t2 = t
local foo = t.x
end
local bar = t.x
)");
LUAU_REQUIRE_NO_ERRORS(result);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK("{| x: number |}" == toString(requireTypeAtPosition({4, 23})));
CHECK("number" == toString(requireTypeAtPosition({5, 26})));
}
CHECK_EQ("number?", toString(requireType("bar")));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "index_on_a_refined_property")
{
CheckResult result = check(R"(
local t: {x: {y: string}?} = {x = {y = "hello!"}}
if t.x then
print(t.x.y)
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(BuiltinsFixture, "assert_non_binary_expressions_actually_resolve_constraints")
{
CheckResult result = check(R"(
local foo: string? = "hello"
assert(foo)
local bar: string = foo
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(Fixture, "lvalue_is_equal_to_another_lvalue")
{
CheckResult result = check(R"(
local function f(a: (string | number)?, b: boolean?)
if a == b then
local foo, bar = a, b
else
local foo, bar = a, b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ(toString(requireTypeAtPosition({3, 33})), "(number | string)?"); // a == b
CHECK_EQ(toString(requireTypeAtPosition({3, 36})), "boolean?"); // a == b
CHECK_EQ(toString(requireTypeAtPosition({5, 33})), "(number | string)?"); // a ~= b
CHECK_EQ(toString(requireTypeAtPosition({5, 36})), "boolean?"); // a ~= b
}
TEST_CASE_FIXTURE(Fixture, "lvalue_is_equal_to_a_term")
{
CheckResult result = check(R"(
local function f(a: (string | number)?)
if a == 1 then
local foo = a
else
local foo = a
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ(toString(requireTypeAtPosition({3, 28})), "(number | string)?"); // a == 1;
CHECK_EQ(toString(requireTypeAtPosition({5, 28})), "(number | string)?"); // a ~= 1
}
TEST_CASE_FIXTURE(Fixture, "term_is_equal_to_an_lvalue")
{
CheckResult result = check(R"(
local function f(a: (string | number)?)
if "hello" == a then
local foo = a
else
local foo = a
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ(toString(requireTypeAtPosition({3, 28})), R"("hello")"); // a == "hello"
CHECK_EQ(toString(requireTypeAtPosition({5, 28})), R"(((string & ~"hello") | number)?)"); // a ~= "hello"
}
else
{
CHECK_EQ(toString(requireTypeAtPosition({3, 28})), R"("hello")"); // a == "hello"
CHECK_EQ(toString(requireTypeAtPosition({5, 28})), R"((number | string)?)"); // a ~= "hello"
}
}
TEST_CASE_FIXTURE(Fixture, "lvalue_is_not_nil")
{
CheckResult result = check(R"(
local function f(a: (string | number)?)
if a ~= nil then
local foo = a
else
local foo = a
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ(toString(requireTypeAtPosition({3, 28})), "number | string"); // a ~= nil
CHECK_EQ(toString(requireTypeAtPosition({5, 28})), "(number | string)?"); // a == nil
}
TEST_CASE_FIXTURE(Fixture, "free_type_is_equal_to_an_lvalue")
{
CheckResult result = check(R"(
local function f(a, b: string?)
if a == b then
local foo, bar = a, b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ(toString(requireTypeAtPosition({3, 33})), "a"); // a == b
CHECK_EQ(toString(requireTypeAtPosition({3, 36})), "string?"); // a == b
}
TEST_CASE_FIXTURE(Fixture, "unknown_lvalue_is_not_synonymous_with_other_on_not_equal")
{
CheckResult result = check(R"(
local function f(a: any, b: {x: number}?)
if a ~= b then
local foo, bar = a, b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ(toString(requireTypeAtPosition({3, 33})), "any"); // a ~= b
CHECK_EQ(toString(requireTypeAtPosition({3, 36})), "{| x: number |}?"); // a ~= b
}
TEST_CASE_FIXTURE(Fixture, "string_not_equal_to_string_or_nil")
{
CheckResult result = check(R"(
local t: {string} = {"hello"}
local a: string = t[1]
local b: string? = nil
if a ~= b then
local foo, bar = a, b
else
local foo, bar = a, b
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ(toString(requireTypeAtPosition({6, 29})), "string"); // a ~= b
CHECK_EQ(toString(requireTypeAtPosition({6, 32})), "string?"); // a ~= b
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ(toString(requireTypeAtPosition({8, 29})), "string?"); // a == b
CHECK_EQ(toString(requireTypeAtPosition({8, 32})), "string?"); // a == b
}
else
{
CHECK_EQ(toString(requireTypeAtPosition({8, 29})), "string"); // a == b
CHECK_EQ(toString(requireTypeAtPosition({8, 32})), "string?"); // a == b
}
}
TEST_CASE_FIXTURE(Fixture, "narrow_property_of_a_bounded_variable")
{
CheckResult result = check(R"(
local t
local u: {x: number?} = {x = nil}
t = u
if t.x then
local foo: number = t.x
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(BuiltinsFixture, "type_narrow_to_vector")
{
CheckResult result = check(R"(
local function f(x)
if type(x) == "vector" then
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("*error-type*", toString(requireTypeAtPosition({3, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "nonoptional_type_can_narrow_to_nil_if_sense_is_true")
{
CheckResult result = check(R"(
local t = {"hello"}
local v = t[2]
if type(v) == "nil" then
local foo = v
else
local foo = v
end
if not (type(v) ~= "nil") then
local foo = v
else
local foo = v
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({4, 24}))); // type(v) == "nil"
CHECK_EQ("string", toString(requireTypeAtPosition({6, 24}))); // type(v) ~= "nil"
CHECK_EQ("nil", toString(requireTypeAtPosition({10, 24}))); // equivalent to type(v) == "nil"
CHECK_EQ("string", toString(requireTypeAtPosition({12, 24}))); // equivalent to type(v) ~= "nil"
}
TEST_CASE_FIXTURE(BuiltinsFixture, "typeguard_not_to_be_string")
{
CheckResult result = check(R"(
local function f(x: string | number | boolean)
if type(x) ~= "string" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("boolean | number", toString(requireTypeAtPosition({3, 28}))); // type(x) ~= "string"
CHECK_EQ("string", toString(requireTypeAtPosition({5, 28}))); // type(x) == "string"
}
TEST_CASE_FIXTURE(BuiltinsFixture, "typeguard_narrows_for_table")
{
CheckResult result = check(R"(
local function f(x: string | {x: number} | {y: boolean})
if type(x) == "table" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("{| x: number |} | {| y: boolean |}", toString(requireTypeAtPosition({3, 28}))); // type(x) == "table"
CHECK_EQ("string", toString(requireTypeAtPosition({5, 28}))); // type(x) ~= "table"
}
TEST_CASE_FIXTURE(BuiltinsFixture, "typeguard_narrows_for_functions")
{
CheckResult result = check(R"(
local function weird(x: string | ((number) -> string))
if type(x) == "function" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("(number) -> string", toString(requireTypeAtPosition({3, 28}))); // type(x) == "function"
CHECK_EQ("string", toString(requireTypeAtPosition({5, 28}))); // type(x) ~= "function"
}
TEST_CASE_FIXTURE(BuiltinsFixture, "type_guard_can_filter_for_intersection_of_tables")
{
CheckResult result = check(R"(
type XYCoord = {x: number} & {y: number}
local function f(t: XYCoord?)
if type(t) == "table" then
local foo = t
else
local foo = t
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
ToStringOptions opts;
opts.exhaustive = true;
CHECK_EQ("{| x: number |} & {| y: number |}", toString(requireTypeAtPosition({4, 28}), opts));
CHECK_EQ("nil", toString(requireTypeAtPosition({6, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "type_guard_can_filter_for_overloaded_function")
{
CheckResult result = check(R"(
type SomeOverloadedFunction = ((number) -> string) & ((string) -> number)
local function f(g: SomeOverloadedFunction?)
if type(g) == "function" then
local foo = g
else
local foo = g
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("((number) -> string) & ((string) -> number)", toString(requireTypeAtPosition({4, 28})));
CHECK_EQ("nil", toString(requireTypeAtPosition({6, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "type_guard_narrowed_into_nothingness")
{
CheckResult result = check(R"(
local function f(t: {x: number})
if type(t) ~= "table" then
local foo = t
error(("Expected a table, got %s"):format(type(t)))
end
return t.x + 1
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("never", toString(requireTypeAtPosition({3, 28})));
}
TEST_CASE_FIXTURE(Fixture, "not_a_or_not_b")
{
CheckResult result = check(R"(
local function f(a: number?, b: number?)
if (not a) or (not b) then
local foo = a
local bar = b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("number?", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("number?", toString(requireTypeAtPosition({4, 28})));
}
TEST_CASE_FIXTURE(Fixture, "not_a_or_not_b2")
{
CheckResult result = check(R"(
local function f(a: number?, b: number?)
if not (a and b) then
local foo = a
local bar = b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("number?", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("number?", toString(requireTypeAtPosition({4, 28})));
}
TEST_CASE_FIXTURE(Fixture, "not_a_and_not_b")
{
CheckResult result = check(R"(
local function f(a: number?, b: number?)
if (not a) and (not b) then
local foo = a
local bar = b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("nil", toString(requireTypeAtPosition({4, 28})));
}
TEST_CASE_FIXTURE(Fixture, "not_a_and_not_b2")
{
CheckResult result = check(R"(
local function f(a: number?, b: number?)
if not (a or b) then
local foo = a
local bar = b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("nil", toString(requireTypeAtPosition({4, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "either_number_or_string")
{
CheckResult result = check(R"(
local function f(x: any, y: unknown)
if type(x) == "number" or type(x) == "string" then
local foo = x
end
if type(y) == "number" or type(y) == "string" then
local foo = y
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("*error-type* | number | string", toString(requireTypeAtPosition({3, 28})));
else
CHECK_EQ("number | string", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("number | string", toString(requireTypeAtPosition({6, 28})));
}
TEST_CASE_FIXTURE(Fixture, "not_t_or_some_prop_of_t")
{
CheckResult result = check(R"(
local function f(t: {x: boolean}?)
if not t or t.x then
local foo = t
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("{| x: true |}?", toString(requireTypeAtPosition({3, 28})));
else
CHECK_EQ("{| x: boolean |}?", toString(requireTypeAtPosition({3, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "assert_a_to_be_truthy_then_assert_a_to_be_number")
{
CheckResult result = check(R"(
local a: (number | string)?
assert(a)
local b = a
assert(type(a) == "number")
local c = a
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("number | string", toString(requireTypeAtPosition({3, 18})));
CHECK_EQ("number", toString(requireTypeAtPosition({5, 18})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "merge_should_be_fully_agnostic_of_hashmap_ordering")
{
// This bug came up because there was a mistake in Luau::merge where zipping on two maps would produce the wrong merged result.
CheckResult result = check(R"(
local function f(b: string | { x: string }, a)
assert(type(a) == "string")
assert(type(b) == "string" or type(b) == "table")
if type(b) == "string" then
local foo = b
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("string", toString(requireTypeAtPosition({6, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "refine_the_correct_types_opposite_of_when_a_is_not_number_or_string")
{
CheckResult result = check(R"(
local function f(a: string | number | boolean)
if type(a) ~= "number" and type(a) ~= "string" then
local foo = a
else
local foo = a
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("boolean", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("number | string", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "is_truthy_constraint_ifelse_expression")
{
CheckResult result = check(R"(
function f(v:string?)
return if v then v else tostring(v)
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("string", toString(requireTypeAtPosition({2, 29})));
CHECK_EQ("nil", toString(requireTypeAtPosition({2, 45})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "invert_is_truthy_constraint_ifelse_expression")
{
CheckResult result = check(R"(
function f(v:string?)
return if not v then tostring(v) else v
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({2, 42})));
CHECK_EQ("string", toString(requireTypeAtPosition({2, 50})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "type_comparison_ifelse_expression")
{
CheckResult result = check(R"(
function returnOne(x)
return 1
end
function f(v:any)
return if typeof(v) == "number" then v else returnOne(v)
end
function g(v:unknown)
return if typeof(v) == "number" then v else returnOne(v)
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ("*error-type* | number", toString(requireTypeAtPosition({6, 49})));
CHECK_EQ("*error-type* | ~number", toString(requireTypeAtPosition({6, 66})));
}
else
{
CHECK_EQ("number", toString(requireTypeAtPosition({6, 49})));
CHECK_EQ("any", toString(requireTypeAtPosition({6, 66})));
}
CHECK_EQ("number", toString(requireTypeAtPosition({10, 49})));
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("unknown & ~number", toString(requireTypeAtPosition({10, 66})));
else
CHECK_EQ("unknown", toString(requireTypeAtPosition({10, 66})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "is_truthy_constraint_while_expression")
{
CheckResult result = check(R"(
function f(v:string?)
while v do
local foo = v
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("string", toString(requireTypeAtPosition({3, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "invert_is_truthy_constraint_while_expression")
{
CheckResult result = check(R"(
function f(v:string?)
while not v do
local foo = v
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({3, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "refine_the_correct_types_opposite_of_while_a_is_not_number_or_string")
{
CheckResult result = check(R"(
local function f(a: string | number | boolean)
while type(a) ~= "number" and type(a) ~= "string" do
local foo = a
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("boolean", toString(requireTypeAtPosition({3, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "correctly_lookup_a_shadowed_local_that_which_was_previously_refined")
{
CheckResult result = check(R"(
local foo: string? = "hi"
assert(foo)
local foo: number = 5
print(foo:sub(1, 1))
)");
LUAU_REQUIRE_ERROR_COUNT(1, result);
CHECK_EQ("Type 'number' does not have key 'sub'", toString(result.errors[0]));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "correctly_lookup_property_whose_base_was_previously_refined")
{
CheckResult result = check(R"(
type T = {x: string | number}
local t: T? = {x = "hi"}
if t then
if type(t.x) == "string" then
local foo = t.x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("string", toString(requireTypeAtPosition({5, 30})));
}
TEST_CASE_FIXTURE(Fixture, "correctly_lookup_property_whose_base_was_previously_refined2")
{
CheckResult result = check(R"(
type T = { x: { y: number }? }
local function f(t: T?)
if t and t.x then
local foo = t.x.y
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("number", toString(requireTypeAtPosition({5, 32})));
}
TEST_CASE_FIXTURE(Fixture, "apply_refinements_on_astexprindexexpr_whose_subscript_expr_is_constant_string")
{
CheckResult result = check(R"(
type T = { [string]: { prop: number }? }
local t: T = {}
if t["hello"] then
local foo = t["hello"].prop
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(Fixture, "discriminate_from_truthiness_of_x")
{
CheckResult result = check(R"(
type T = {tag: "missing", x: nil} | {tag: "exists", x: string}
local function f(t: T)
if t.x then
local foo = t
else
local bar = t
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ(R"({| tag: "exists", x: string |})", toString(requireTypeAtPosition({5, 28})));
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ(R"({| tag: "missing", x: nil |})", toString(requireTypeAtPosition({7, 28})));
else
CHECK_EQ(R"({| tag: "exists", x: string |} | {| tag: "missing", x: nil |})", toString(requireTypeAtPosition({7, 28})));
}
TEST_CASE_FIXTURE(Fixture, "discriminate_tag")
{
CheckResult result = check(R"(
type Cat = {tag: "Cat", name: string, catfood: string}
type Dog = {tag: "Dog", name: string, dogfood: string}
type Animal = Cat | Dog
local function f(animal: Animal)
if animal.tag == "Cat" then
local cat = animal
elseif animal.tag == "Dog" then
local dog = animal
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Cat", toString(requireTypeAtPosition({7, 33})));
CHECK_EQ("Dog", toString(requireTypeAtPosition({9, 33})));
}
TEST_CASE_FIXTURE(Fixture, "discriminate_tag_with_implicit_else")
{
CheckResult result = check(R"(
type Cat = {tag: "Cat", name: string, catfood: string}
type Dog = {tag: "Dog", name: string, dogfood: string}
type Animal = Cat | Dog
local function f(animal: Animal)
if animal.tag == "Cat" then
local cat = animal
else
local dog = animal
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Cat", toString(requireTypeAtPosition({7, 33})));
CHECK_EQ("Dog", toString(requireTypeAtPosition({9, 33})));
}
TEST_CASE_FIXTURE(Fixture, "and_or_peephole_refinement")
{
CheckResult result = check(R"(
local function len(a: {any})
return a and #a or nil
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(Fixture, "narrow_boolean_to_true_or_false")
{
CheckResult result = check(R"(
local function f(x: boolean)
if x then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("true", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("false", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(Fixture, "discriminate_on_properties_of_disjoint_tables_where_that_property_is_true_or_false")
{
CheckResult result = check(R"(
type Ok<T> = { ok: true, value: T }
type Err<E> = { ok: false, error: E }
type Result<T, E> = Ok<T> | Err<E>
local function apply<T, E>(t: Result<T, E>, f: (T) -> (), g: (E) -> ())
if t.ok then
f(t.value)
else
g(t.error)
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(Fixture, "refine_a_property_not_to_be_nil_through_an_intersection_table")
{
CheckResult result = check(R"(
type T = {} & {f: ((string) -> string)?}
local function f(t: T, x)
if t.f then
t.f(x)
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(RefinementClassFixture, "discriminate_from_isa_of_x")
{
CheckResult result = check(R"(
type T = {tag: "Part", x: Part} | {tag: "Folder", x: Folder}
local function f(t: T)
if t.x:IsA("Part") then
local foo = t
else
local bar = t
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ(R"({| tag: "Part", x: Part |})", toString(requireTypeAtPosition({5, 28})));
CHECK_EQ(R"({| tag: "Folder", x: Folder |})", toString(requireTypeAtPosition({7, 28})));
}
TEST_CASE_FIXTURE(RefinementClassFixture, "typeguard_cast_free_table_to_vector")
{
CheckResult result = check(R"(
local function f(vec)
local X, Y, Z = vec.X, vec.Y, vec.Z
if type(vec) == "vector" then
local foo = vec
elseif typeof(vec) == "Instance" then
local foo = vec
else
local foo = vec
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Vector3", toString(requireTypeAtPosition({5, 28}))); // type(vec) == "vector"
CHECK_EQ("never", toString(requireTypeAtPosition({7, 28}))); // typeof(vec) == "Instance"
CHECK_EQ("{+ X: a, Y: b, Z: c +}", toString(requireTypeAtPosition({9, 28}))); // type(vec) ~= "vector" and typeof(vec) ~= "Instance"
}
TEST_CASE_FIXTURE(RefinementClassFixture, "typeguard_cast_instance_or_vector3_to_vector")
{
CheckResult result = check(R"(
local function f(x: Instance | Vector3)
if typeof(x) == "Vector3" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Vector3", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("Instance", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(RefinementClassFixture, "type_narrow_for_all_the_userdata")
{
CheckResult result = check(R"(
local function f(x: string | number | Instance | Vector3)
if type(x) == "userdata" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Instance | Vector3", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("number | string", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(RefinementClassFixture, "type_narrow_but_the_discriminant_type_isnt_a_class")
{
CheckResult result = check(R"(
local function f(x: string | number | Instance | Vector3)
if type(x) == "any" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ("never", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("Instance | Vector3 | number | string", toString(requireTypeAtPosition({5, 28})));
}
else
{
CHECK_EQ("*error-type*", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("*error-type*", toString(requireTypeAtPosition({5, 28})));
}
}
TEST_CASE_FIXTURE(RefinementClassFixture, "eliminate_subclasses_of_instance")
{
CheckResult result = check(R"(
local function f(x: Part | Folder | string)
if typeof(x) == "Instance" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Folder | Part", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("string", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(RefinementClassFixture, "narrow_from_subclasses_of_instance_or_string_or_vector3")
{
CheckResult result = check(R"(
local function f(x: Part | Folder | string | Vector3)
if typeof(x) == "Instance" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Folder | Part", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("Vector3 | string", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(RefinementClassFixture, "x_as_any_if_x_is_instance_elseif_x_is_table")
{
CheckResult result = check(R"(
--!nonstrict
local function f(x)
if typeof(x) == "Instance" and x:IsA("Folder") then
local foo = x
elseif typeof(x) == "table" then
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ("Folder & Instance & {- -}", toString(requireTypeAtPosition({5, 28})));
CHECK_EQ("(~Folder | ~Instance) & {- -} & never", toString(requireTypeAtPosition({7, 28})));
}
else
{
CHECK_EQ("Folder", toString(requireTypeAtPosition({5, 28})));
CHECK_EQ("any", toString(requireTypeAtPosition({7, 28})));
}
}
TEST_CASE_FIXTURE(RefinementClassFixture, "refine_param_of_type_instance_without_using_typeof")
{
CheckResult result = check(R"(
local function f(x: Instance)
if x:IsA("Folder") then
local foo = x
elseif typeof(x) == "table" then
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Folder", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("never", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(RefinementClassFixture, "refine_param_of_type_folder_or_part_without_using_typeof")
{
CheckResult result = check(R"(
local function f(x: Part | Folder)
if x:IsA("Folder") then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Folder", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("Part", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(RefinementClassFixture, "isa_type_refinement_must_be_known_ahead_of_time")
{
CheckResult result = check(R"(
local function f(x): Instance
if x:IsA("Folder") then
local foo = x
else
local foo = x
end
return x
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Instance", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("Instance", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(RefinementClassFixture, "x_is_not_instance_or_else_not_part")
{
CheckResult result = check(R"(
local function f(x: Part | Folder | string)
if typeof(x) ~= "Instance" or not x:IsA("Part") then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Folder | string", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("Part", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "typeguard_doesnt_leak_to_elseif")
{
CheckResult result = check(R"(
function f(a)
if type(a) == "boolean" then
local a1 = a
elseif a.fn() then
local a2 = a
else
local a3 = a
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(BuiltinsFixture, "refine_unknowns")
{
CheckResult result = check(R"(
local function f(x: unknown)
if type(x) == "string" then
local foo = x
else
local bar = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ("string", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("unknown & ~string", toString(requireTypeAtPosition({5, 28})));
}
else
{
CHECK_EQ("string", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("unknown", toString(requireTypeAtPosition({5, 28})));
}
}
TEST_CASE_FIXTURE(BuiltinsFixture, "refine_boolean")
{
CheckResult result = check(R"(
local function f(x: number | boolean)
if typeof(x) == "boolean" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("boolean", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("number", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "refine_thread")
{
CheckResult result = check(R"(
local function f(x: number | thread)
if typeof(x) == "thread" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("thread", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("number", toString(requireTypeAtPosition({5, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "falsiness_of_TruthyPredicate_narrows_into_nil")
{
CheckResult result = check(R"(
local function f(t: {number})
local x = t[1]
if not x then
local foo = x
else
local bar = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({4, 28})));
CHECK_EQ("number", toString(requireTypeAtPosition({6, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "what_nonsensical_condition")
{
CheckResult result = check(R"(
local function f(x)
if type(x) == "string" and type(x) == "number" then
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("never", toString(requireTypeAtPosition({3, 28})));
}
TEST_CASE_FIXTURE(Fixture, "else_with_no_explicit_expression_should_also_refine_the_tagged_union")
{
CheckResult result = check(R"(
type Ok<T> = { tag: "ok", value: T }
type Err<E> = { tag: "err", err: E }
type Result<T, E> = Ok<T> | Err<E>
function and_then<T, U, E>(r: Result<T, E>, f: (T) -> U): Result<U, E>
if r.tag == "ok" then
return { tag = "ok", value = f(r.value) }
else
return r
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(Fixture, "fuzz_filtered_refined_types_are_followed")
{
CheckResult result = check(R"(
local _
do
local _ = _ ~= _ or _ or _
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(BuiltinsFixture, "refine_unknown_to_table_then_take_the_length")
{
CheckResult result = check(R"(
local function f(x: unknown)
if typeof(x) == "table" then
local len = #x
end
end
)");
if (FFlag::DebugLuauDeferredConstraintResolution)
{
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("table", toString(requireTypeAtPosition({3, 29})));
}
else
{
LUAU_REQUIRE_ERROR_COUNT(1, result);
CHECK_EQ("unknown", toString(requireTypeAtPosition({3, 29})));
}
}
TEST_CASE_FIXTURE(BuiltinsFixture, "refine_unknown_to_table_then_clone_it")
{
CheckResult result = check(R"(
local function f(x: unknown)
if typeof(x) == "table" then
local cloned: {} = table.clone(x)
end
end
)");
if (FFlag::DebugLuauDeferredConstraintResolution)
{
LUAU_REQUIRE_NO_ERRORS(result);
}
else
{
LUAU_REQUIRE_ERROR_COUNT(1, result);
}
}
TEST_CASE_FIXTURE(RefinementClassFixture, "refine_a_param_that_got_resolved_during_constraint_solving_stage")
{
CheckResult result = check(R"(
type Id<T> = T
local function f(x: Id<Id<Part | Folder> | Id<string>>)
if typeof(x) ~= "string" and x:IsA("Part") then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Part", toString(requireTypeAtPosition({5, 28})));
CHECK_EQ("Folder | string", toString(requireTypeAtPosition({7, 28})));
}
TEST_CASE_FIXTURE(RefinementClassFixture, "refine_a_param_that_got_resolved_during_constraint_solving_stage_2")
{
CheckResult result = check(R"(
local function hof(f: (Instance) -> ()) end
hof(function(inst)
if inst:IsA("Part") then
local foo = inst
else
local foo = inst
end
end)
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Part", toString(requireTypeAtPosition({5, 28})));
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("Instance & ~Part", toString(requireTypeAtPosition({7, 28})));
else
CHECK_EQ("Instance", toString(requireTypeAtPosition({7, 28})));
}
TEST_CASE_FIXTURE(Fixture, "refine_a_property_of_some_global")
{
CheckResult result = check(R"(
foo = { bar = 5 :: number? }
if foo.bar then
local bar = foo.bar
end
)");
if (FFlag::DebugLuauDeferredConstraintResolution)
{
LUAU_REQUIRE_ERROR_COUNT(3, result);
CHECK_EQ("~(false?)", toString(requireTypeAtPosition({4, 30})));
}
}
TEST_CASE_FIXTURE(BuiltinsFixture, "dataflow_analysis_can_tell_refinements_when_its_appropriate_to_refine_into_nil_or_never")
{
CheckResult result = check(R"(
local function f(t: {string}, s: string)
local v1 = t[5]
local v2 = v1
if typeof(v1) == "nil" then
local foo = v1
else
local foo = v1
end
if typeof(v2) == "nil" then
local foo = v2
else
local foo = v2
end
if typeof(s) == "nil" then
local foo = s
else
local foo = s
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({6, 28})));
CHECK_EQ("string", toString(requireTypeAtPosition({8, 28})));
CHECK_EQ("nil", toString(requireTypeAtPosition({12, 28})));
CHECK_EQ("string", toString(requireTypeAtPosition({14, 28})));
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ("never", toString(requireTypeAtPosition({18, 28})));
CHECK_EQ("string", toString(requireTypeAtPosition({20, 28})));
}
else
{
CHECK_EQ("nil", toString(requireTypeAtPosition({18, 28})));
CHECK_EQ("string", toString(requireTypeAtPosition({20, 28})));
}
}
TEST_CASE_FIXTURE(Fixture, "cat_or_dog_through_a_local")
{
CheckResult result = check(R"(
type Cat = { tag: "cat", catfood: string }
type Dog = { tag: "dog", dogfood: string }
type Animal = Cat | Dog
local function f(animal: Animal)
local tag = animal.tag
if tag == "dog" then
local dog = animal
elseif tag == "cat" then
local cat = animal
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("Cat | Dog", toString(requireTypeAtPosition({8, 28})));
CHECK_EQ("Cat | Dog", toString(requireTypeAtPosition({10, 28})));
}
TEST_CASE_FIXTURE(Fixture, "prove_that_dataflow_analysis_isnt_doing_alias_tracking_yet")
{
CheckResult result = check(R"(
local function f(tag: "cat" | "dog")
local tag2 = tag
if tag2 == "cat" then
local foo = tag
else
local foo = tag
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ(R"("cat" | "dog")", toString(requireTypeAtPosition({5, 28})));
CHECK_EQ(R"("cat" | "dog")", toString(requireTypeAtPosition({7, 28})));
}
TEST_CASE_FIXTURE(Fixture, "fail_to_refine_a_property_of_subscript_expression")
{
CheckResult result = check(R"(
type Foo = { foo: number? }
local function f(t: {Foo})
if t[1].foo then
local foo = t[1].foo
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("number?", toString(requireTypeAtPosition({4, 34})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "type_annotations_arent_relevant_when_doing_dataflow_analysis")
{
CheckResult result = check(R"(
local function s() return "hello" end
local function f(t: {string})
local s1: string = t[5]
local s2: string = s()
if typeof(s1) == "nil" and typeof(s2) == "nil" then
local foo = s1
local bar = s2
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("nil", toString(requireTypeAtPosition({8, 28})));
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("never", toString(requireTypeAtPosition({9, 28})));
else
CHECK_EQ("nil", toString(requireTypeAtPosition({9, 28})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "function_call_with_colon_after_refining_not_to_be_nil")
{
ScopedFastFlag sff{"DebugLuauDeferredConstraintResolution", true};
CheckResult result = check(R"(
--!strict
export type Observer<T> = {
complete: ((self: Observer<T>) -> ())?,
}
local function _f(handler: Observer<any>)
assert(handler.complete ~= nil)
handler:complete() -- incorrectly gives Value of type '((Observer<any>) -> ())?' could be nil
handler.complete(handler) -- works fine, both forms should avoid the error
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(Fixture, "refinements_should_not_affect_assignment")
{
CheckResult result = check(R"(
local a: unknown = true
if a == true then
a = 'not even remotely similar to a boolean'
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(BuiltinsFixture, "refinements_should_preserve_error_suppression")
{
CheckResult result = check(R"(
local a: any = {}
local b
if typeof(a) == "table" then
b = a.field
end
)");
if (FFlag::DebugLuauDeferredConstraintResolution)
LUAU_REQUIRE_NO_ERRORS(result);
else
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(BuiltinsFixture, "many_refinements_on_val")
{
CheckResult result = check(R"(
local function is_nan(val: any): boolean
return type(val) == "number" and val ~= val
end
local function is_js_boolean(val: any): boolean
return not not val and val ~= 0 and val ~= "" and not is_nan(val)
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("(any) -> boolean", toString(requireType("is_nan")));
CHECK_EQ("(any) -> boolean", toString(requireType("is_js_boolean")));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "refine_unknown_to_table")
{
ScopedFastFlag sff{"DebugLuauDeferredConstraintResolution", true};
// this test is DCR-only as an instance of DCR fixing a bug in the old solver
CheckResult result = check(R"(
local a : unknown = nil
local idx, val
if typeof(a) == "table" then
for i, v in a do
idx = i
val = v
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("unknown", toString(requireType("idx")));
CHECK_EQ("unknown", toString(requireType("val")));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "conditional_refinement_should_stay_error_suppressing")
{
ScopedFastFlag sff{"DebugLuauDeferredConstraintResolution", true};
// this test is DCR-only as an instance of DCR fixing a bug in the old solver
CheckResult result = check(R"(
local function test(element: any?)
if element then
local owner = element._owner
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_SUITE_END();