luau/tests/InferPolarity.test.cpp
vegorov-rbx 55f3e00938
Sync to upstream/release/687 (#1954)
## What's Changed?

This week we have an update with an implementation for one of the RFCs
we had approved before, an improvement of the new type solver and a
small Lua 5.1 C API compatibility improvement.

* `@deprecated` attribute can now have a custom suggestion for a
replacement and a reason message as described in [deprecated attribute
parameters
RFC](https://rfcs.luau.org/syntax-attribute-functions-deprecated.html)

For example:
```luau
@[deprecated {reason = "foo suffers from performance issues", use = "bar"}]
local function foo()
    ...
end

-- Function 'foo' is deprecated, use 'bar' instead. foo suffers from performance issues
foo()
```

* `lua_cpcall` C API function has been restored both for compatibility
with Lua 5.1 and as a safe way to enter protected call environment to
work with Luau C API functions that may error

Instead of
```
if (!lua_checkstack(L, 2))
    return -1;
lua_pushcfunction(L, test, nullptr);
lua_pushlightuserdata(L, context);
int status = lua_pcall(L, 1, 0, 0);
```
you can simply do 
```
int status = lua_cpcall(L, test, context);
```

* In Luau CLI, required module return values can now have any type

## New Type Solver
- Additional improvements on type refinements used with external types
should fix some reported false positive errors where types refined to
`never`
- Fixed an issue in recursive refinement types in a form of `t1 where t1
= refine<t1, _>` getting 'stuck'
- Fixed an issue in subtyping of generic functions, it is now possible
to assign `<T>(T, (T) -> T) -> T` to `(number, <X>(X) -> X) -> number`
- Fixed an ICE caused by recursive types (Fixes #1686)
- Added additional iteration and recursion limits to stop the type
solver before system resources are used up

## Internal Contributors

Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Annie Tang <annietang@roblox.com>
Co-authored-by: Ariel Weiss <aaronweiss@roblox.com>
Co-authored-by: Hunter Goldstein <hgoldstein@roblox.com>
Co-authored-by: Ilya Rezvov <irezvov@roblox.com>
Co-authored-by: Sora Kanosue <skanosue@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
2025-08-15 11:48:43 -07:00

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2.9 KiB
C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#include "Fixture.h"
#include "Luau/InferPolarity.h"
#include "Luau/Polarity.h"
#include "Luau/Type.h"
#include "Luau/TypeArena.h"
using namespace Luau;
LUAU_FASTFLAG(LuauEagerGeneralization4);
LUAU_FASTFLAG(LuauTrackFreeInteriorTypePacks)
LUAU_FASTFLAG(LuauResetConditionalContextProperly)
TEST_SUITE_BEGIN("InferPolarity");
TEST_CASE_FIXTURE(Fixture, "T where T = { m: <a>(a) -> T }")
{
ScopedFastFlag sff[] = {
{FFlag::LuauEagerGeneralization4, true},
{FFlag::LuauTrackFreeInteriorTypePacks, true},
{FFlag::LuauResetConditionalContextProperly, true}
};
TypeArena arena;
ScopePtr globalScope = std::make_shared<Scope>(getBuiltins()->anyTypePack);
TypeId tType = arena.addType(BlockedType{});
TypeId aType = arena.addType(GenericType{globalScope.get(), "a"});
TypeId mType = arena.addType(FunctionType{
TypeLevel{},
/* generics */ {aType},
/* genericPacks */ {},
/* argPack */ arena.addTypePack({aType}),
/* retPack */ arena.addTypePack({tType})
});
emplaceType<TableType>(
asMutable(tType),
TableType{
TableType::Props{{"m", Property::rw(mType)}},
/* indexer */ std::nullopt,
TypeLevel{},
globalScope.get(),
TableState::Sealed
}
);
inferGenericPolarities(NotNull{&arena}, NotNull{globalScope.get()}, tType);
const GenericType* aGeneric = get<GenericType>(aType);
REQUIRE(aGeneric);
CHECK(aGeneric->polarity == Polarity::Negative);
}
TEST_CASE_FIXTURE(Fixture, "<a, b>({ read x: a, write x: b }) -> ()")
{
ScopedFastFlag sffs[] = {
{FFlag::LuauEagerGeneralization4, true},
{FFlag::LuauTrackFreeInteriorTypePacks, true},
{FFlag::LuauResetConditionalContextProperly, true},
};
TypeArena arena;
ScopePtr globalScope = std::make_shared<Scope>(getBuiltins()->anyTypePack);
TypeId aType = arena.addType(GenericType{globalScope.get(), "a"});
TypeId bType = arena.addType(GenericType{globalScope.get(), "b"});
TableType ttv;
ttv.state = TableState::Sealed;
ttv.props["x"] = Property::create({aType}, {bType});
TypeId mType = arena.addType(FunctionType{
TypeLevel{},
/* generics */ {aType, bType},
/* genericPacks */ {},
/* argPack */ arena.addTypePack({arena.addType(std::move(ttv))}),
/* retPack */ builtinTypes->emptyTypePack,
});
inferGenericPolarities(NotNull{&arena}, NotNull{globalScope.get()}, mType);
const GenericType* aGeneric = get<GenericType>(aType);
REQUIRE(aGeneric);
CHECK(aGeneric->polarity == Polarity::Negative);
const GenericType* bGeneric = get<GenericType>(bType);
REQUIRE(bGeneric);
CHECK(bGeneric->polarity == Polarity::Positive);
}
TEST_SUITE_END();