luau/tests/Generalization.test.cpp
2024-05-16 15:22:22 -07:00

120 lines
3.1 KiB
C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#include "Luau/Generalization.h"
#include "Luau/Scope.h"
#include "Luau/ToString.h"
#include "Luau/Type.h"
#include "Luau/TypeArena.h"
#include "Luau/Error.h"
#include "ScopedFlags.h"
#include "doctest.h"
using namespace Luau;
LUAU_FASTFLAG(DebugLuauDeferredConstraintResolution)
TEST_SUITE_BEGIN("Generalization");
struct GeneralizationFixture
{
TypeArena arena;
BuiltinTypes builtinTypes;
Scope scope{builtinTypes.anyTypePack};
ToStringOptions opts;
ScopedFastFlag sff{FFlag::DebugLuauDeferredConstraintResolution, true};
std::pair<TypeId, FreeType*> freshType()
{
FreeType ft{&scope, builtinTypes.neverType, builtinTypes.unknownType};
TypeId ty = arena.addType(ft);
FreeType* ftv = getMutable<FreeType>(ty);
REQUIRE(ftv != nullptr);
return {ty, ftv};
}
std::string toString(TypeId ty)
{
return ::Luau::toString(ty, opts);
}
std::string toString(TypePackId ty)
{
return ::Luau::toString(ty, opts);
}
std::optional<TypeId> generalize(TypeId ty)
{
return ::Luau::generalize(NotNull{&arena}, NotNull{&builtinTypes}, NotNull{&scope}, ty);
}
};
TEST_CASE_FIXTURE(GeneralizationFixture, "generalize_a_type_that_is_bounded_by_another_generalizable_type")
{
auto [t1, ft1] = freshType();
auto [t2, ft2] = freshType();
// t2 <: t1 <: unknown
// unknown <: t2 <: t1
ft1->lowerBound = t2;
ft2->upperBound = t1;
ft2->lowerBound = builtinTypes.unknownType;
auto t2generalized = generalize(t2);
REQUIRE(t2generalized);
CHECK(follow(t1) == follow(t2));
auto t1generalized = generalize(t1);
REQUIRE(t1generalized);
CHECK(builtinTypes.unknownType == follow(t1));
CHECK(builtinTypes.unknownType == follow(t2));
}
// Same as generalize_a_type_that_is_bounded_by_another_generalizable_type
// except that we generalize the types in the opposite order
TEST_CASE_FIXTURE(GeneralizationFixture, "generalize_a_type_that_is_bounded_by_another_generalizable_type_in_reverse_order")
{
auto [t1, ft1] = freshType();
auto [t2, ft2] = freshType();
// t2 <: t1 <: unknown
// unknown <: t2 <: t1
ft1->lowerBound = t2;
ft2->upperBound = t1;
ft2->lowerBound = builtinTypes.unknownType;
auto t1generalized = generalize(t1);
REQUIRE(t1generalized);
CHECK(follow(t1) == follow(t2));
auto t2generalized = generalize(t2);
REQUIRE(t2generalized);
CHECK(builtinTypes.unknownType == follow(t1));
CHECK(builtinTypes.unknownType == follow(t2));
}
TEST_CASE_FIXTURE(GeneralizationFixture, "dont_traverse_into_class_types_when_generalizing")
{
auto [propTy, _] = freshType();
TypeId cursedClass = arena.addType(ClassType{"Cursed", {{"oh_no", Property::readonly(propTy)}}, std::nullopt, std::nullopt, {}, {}, ""});
auto genClass = generalize(cursedClass);
REQUIRE(genClass);
auto genPropTy = get<ClassType>(*genClass)->props.at("oh_no").readTy;
CHECK(is<FreeType>(*genPropTy));
}
TEST_SUITE_END();