luau/tests/TypeInfer.refinements.test.cpp
vegorov-rbx b570ff0a37
Sync to upstream/release/564 (#841)
This week we only have updates to new type solver and JIT. Both projects
are still in the process of being built out. Neither are ready for
general use yet.

In the new solver, we fixed issues with recursive type aliases.
Duplicated type parameters are once again reported, exported types are
being recorder and function argument names are placed inside function
types.
We also made improvements to restore parts of bidirectional type
tracking.

On native code generation side, namecall instruction lowering was fixed,
we fixed inconsistencies in IR command definitions and added utility
function to help with constant folding.
2023-02-17 15:41:51 -08:00

1543 lines
43 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)
LUAU_FASTFLAG(LuauNegatedClassTypes)
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;
unfreeze(typeChecker.globalTypes);
TypePackId booleanPack = typeChecker.globalTypes.addTypePack({typeChecker.booleanType});
freeze(typeChecker.globalTypes);
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 = typeChecker.globalTypes;
NotNull<Scope> scope{typeChecker.globalScope.get()};
std::optional<TypeId> rootSuper = FFlag::LuauNegatedClassTypes ? std::make_optional(typeChecker.builtinTypes->classType) : std::nullopt;
unfreeze(arena);
TypeId vec3 = arena.addType(ClassType{"Vector3", {}, rootSuper, std::nullopt, {}, nullptr, "Test"});
getMutable<ClassType>(vec3)->props = {
{"X", Property{typeChecker.numberType}},
{"Y", Property{typeChecker.numberType}},
{"Z", Property{typeChecker.numberType}},
};
TypeId inst = arena.addType(ClassType{"Instance", {}, rootSuper, std::nullopt, {}, nullptr, "Test"});
TypePackId isAParams = arena.addTypePack({inst, typeChecker.stringType});
TypePackId isARets = arena.addTypePack({typeChecker.booleanType});
TypeId isA = arena.addType(FunctionType{isAParams, isARets});
getMutable<FunctionType>(isA)->magicFunction = magicFunctionInstanceIsA;
getMutable<FunctionType>(isA)->dcrMagicRefinement = dcrMagicRefinementInstanceIsA;
getMutable<ClassType>(inst)->props = {
{"Name", Property{typeChecker.stringType}},
{"IsA", Property{isA}},
};
TypeId folder = typeChecker.globalTypes.addType(ClassType{"Folder", {}, inst, std::nullopt, {}, nullptr, "Test"});
TypeId part = typeChecker.globalTypes.addType(ClassType{"Part", {}, inst, std::nullopt, {}, nullptr, "Test"});
getMutable<ClassType>(part)->props = {
{"Position", Property{vec3}},
};
typeChecker.globalScope->exportedTypeBindings["Vector3"] = TypeFun{{}, vec3};
typeChecker.globalScope->exportedTypeBindings["Instance"] = TypeFun{{}, inst};
typeChecker.globalScope->exportedTypeBindings["Folder"] = TypeFun{{}, folder};
typeChecker.globalScope->exportedTypeBindings["Part"] = TypeFun{{}, part};
for (const auto& [name, ty] : typeChecker.globalScope->exportedTypeBindings)
persist(ty.type);
freeze(typeChecker.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 result = check(R"(
function f(s: any)
if type(s) == "number" then
local n = s
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("number", toString(requireTypeAtPosition({3, 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: any)
if type(x) == "string" then
f(x)
end
end
)");
LUAU_REQUIRE_ERROR_COUNT(1, result);
CHECK_EQ("Type 'string' could not be converted into 'number'", toString(result.errors[0]));
}
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
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)
if type(x) == "number" or type(x) == "string" then
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("number | string", toString(requireTypeAtPosition({3, 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);
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
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("number", toString(requireTypeAtPosition({6, 49})));
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("~number", toString(requireTypeAtPosition({6, 66})));
else
CHECK_EQ("any", toString(requireTypeAtPosition({6, 66})));
}
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);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ(R"({| catfood: string, name: string, tag: "Cat" |})", toString(requireTypeAtPosition({7, 33})));
CHECK_EQ(R"({| dogfood: string, name: string, tag: "Dog" |})", toString(requireTypeAtPosition({9, 33})));
}
else
{
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);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ(R"({| catfood: string, name: string, tag: "Cat" |})", toString(requireTypeAtPosition({7, 33})));
CHECK_EQ(R"({| dogfood: string, name: string, tag: "Dog" |})", toString(requireTypeAtPosition({9, 33})));
}
else
{
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("~string", toString(requireTypeAtPosition({5, 28})));
}
else
{
CHECK_EQ("string", toString(requireTypeAtPosition({3, 28})));
CHECK_EQ("unknown", 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
)");
if (FFlag::DebugLuauDeferredConstraintResolution)
{
// Without a realistic motivating case, it's hard to tell if it's important for this to work without errors.
LUAU_REQUIRE_ERROR_COUNT(1, result);
CHECK(get<NormalizationTooComplex>(result.errors[0]));
}
else
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("a & table", toString(requireTypeAtPosition({3, 29})));
}
else
{
LUAU_REQUIRE_ERROR_COUNT(1, result);
CHECK_EQ("unknown", toString(requireTypeAtPosition({3, 29})));
}
}
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_SUITE_END();