luau/tests/TypeInfer.refinements.test.cpp
aaron 9c588be16d
Sync to upstream/release/610 (#1154)
# What's changed?

* Check interrupt handler inside the pattern match engine to eliminate
potential for programs to hang during string library function execution.
* Allow iteration over table properties to pass the old type solver. 

### Native Code Generation

* Use in-place memory operands for math library operations on x64.
* Replace opaque bools with separate enum classes in IrDump to improve
code maintainability.
* Translate operations on inferred vectors to IR.
* Enable support for debugging native-compiled functions in Roblox
Studio.

### New Type Solver

* Rework type inference for boolean and string literals to introduce
bounded free types (bounded below by the singleton type, and above by
the primitive type) and reworked primitive type constraint to decide
which is the appropriate type for the literal.
* Introduce `FunctionCheckConstraint` to handle bidirectional
typechecking for function calls, pushing the expected parameter types
from the function onto the arguments.
* Introduce `union` and `intersect` type families to compute deferred
simplified unions and intersections to be employed by the constraint
generation logic in the new solver.
* Implement support for expanding the domain of local types in
`Unifier2`.
* Rework type inference for iteration variables bound by for in loops to
use local types.
* Change constraint blocking logic to use a set to prevent accidental
re-blocking.
* Add logic to detect missing return statements in functions.

### Internal Contributors

Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>

---------

Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
2024-01-26 19:20:56 -08:00

2026 lines
57 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 result = 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(result);
// 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);
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ(toString(requireTypeAtPosition({3, 33})), "unknown"); // a == b
else
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
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ(toString(requireTypeAtPosition({3, 36})), "{ x: number }?"); // a ~= b
else
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);
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("{ x: number } | { y: boolean }", toString(requireTypeAtPosition({3, 28}))); // type(x) == "table"
else
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;
if (FFlag::DebugLuauDeferredConstraintResolution)
CHECK_EQ("{ x: number } & { y: number }", toString(requireTypeAtPosition({4, 28}), opts));
else
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);
if (FFlag::DebugLuauDeferredConstraintResolution)
{
CHECK_EQ(R"({ tag: "Part", x: Part })", toString(requireTypeAtPosition({5, 28})));
CHECK_EQ(R"({ tag: "Folder", x: Folder })", toString(requireTypeAtPosition({7, 28})));
}
else
{
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, "refine_buffer")
{
CheckResult result = check(R"(
local function f(x: number | buffer)
if typeof(x) == "buffer" then
local foo = x
else
local foo = x
end
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("buffer", 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")
{
// don't run this test at all without DCR
if (!FFlag::DebugLuauDeferredConstraintResolution)
return;
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{FFlag::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 f(a: unknown)
if typeof(a) == "table" then
for i, v in a do
return i, v
end
end
error("")
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
CHECK_EQ("(unknown) -> (unknown, unknown)", toString(requireType("f")));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "conditional_refinement_should_stay_error_suppressing")
{
ScopedFastFlag sff{FFlag::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_CASE_FIXTURE(BuiltinsFixture, "globals_can_be_narrowed_too")
{
CheckResult result = check(R"(
if typeof(string) == 'string' then
local foo = string
end
)");
CHECK("never" == toString(requireTypeAtPosition(Position{2, 24})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "luau_polyfill_isindexkey_refine_conjunction")
{
CheckResult result = check(R"(
local function isIndexKey(k, contiguousLength)
return type(k) == "number"
and k <= contiguousLength -- nothing out of bounds
and 1 <= k -- nothing illegal for array indices
and math.floor(k) == k -- no float keys
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(BuiltinsFixture, "luau_polyfill_isindexkey_refine_conjunction_variant")
{
CheckResult result = check(R"(
local function isIndexKey(k, contiguousLength: number)
return type(k) == "number"
and k <= contiguousLength -- nothing out of bounds
and 1 <= k -- nothing illegal for array indices
and math.floor(k) == k -- no float keys
end
)");
LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(BuiltinsFixture, "globals_can_be_narrowed_too")
{
CheckResult result = check(R"(
if typeof(string) == 'string' then
local foo = string
end
)");
CHECK("never" == toString(requireTypeAtPosition(Position{2, 24})));
}
TEST_CASE_FIXTURE(BuiltinsFixture, "ex")
{
CheckResult result = check(R"(
local function f(x: string | number)
if typeof((x)) == "string" then
local y = x
end
end
)");
TypeId t = requireTypeAtPosition({3, 18});
CHECK("string" == toString(t));
}
TEST_SUITE_END();