luau-analyzer-sys 0.1.1

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details

#include "Fixture.h"

#include "ScopedFlags.h"
#include "doctest.h"

using namespace Luau;

LUAU_FASTFLAG(DebugLuauForceOldSolver)
LUAU_FASTFLAG(LuauOverloadGetsInstantiated2)
LUAU_FASTFLAG(LuauReplacerRespectsReboundGenerics)

TEST_SUITE_BEGIN("TypeSingletons");

TEST_CASE_FIXTURE(Fixture, "function_args_infer_singletons")
{
    CheckResult result = check(R"(
--!strict
type Phase = "A" | "B" | "C"
local function f(e : Phase) : number
    return 0
end
local e = f("B")
)");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "bool_singletons")
{
    CheckResult result = check(R"(
        local a: true = true
        local b: false = false
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "string_singletons")
{
    CheckResult result = check(R"(
        local a: "foo" = "foo"
        local b: "bar" = "bar"
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "string_singleton_function_call")
{
    if (FFlag::DebugLuauForceOldSolver)
        return;

    CheckResult result = check(R"(
        local x = "a"
        function f(x: "a") end
        f(x)
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "bool_singletons_mismatch")
{
    CheckResult result = check(R"(
        local a: true = false
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);
    CHECK_EQ("Expected this to be 'true', but got 'false'", toString(result.errors[0]));
}

TEST_CASE_FIXTURE(Fixture, "string_singletons_mismatch")
{
    CheckResult result = check(R"(
        local a: "foo" = "bar"
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);
    CHECK_EQ("Expected this to be '\"foo\"', but got '\"bar\"'", toString(result.errors[0]));
}

TEST_CASE_FIXTURE(Fixture, "string_singletons_escape_chars")
{
    CheckResult result = check(R"(
        local a: "\n" = "\000\r"
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);
    CHECK_EQ(R"(Expected this to be '"\n"', but got '"\000\r"')", toString(result.errors[0]));
}

TEST_CASE_FIXTURE(Fixture, "bool_singleton_subtype")
{
    CheckResult result = check(R"(
        local a: true = true
        local b: boolean = a
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "string_singleton_subtype")
{
    CheckResult result = check(R"(
        local a: "foo" = "foo"
        local b: string = a
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "string_singleton_subtype_multi_assignment")
{
    CheckResult result = check(R"(
        local a: "foo" = "foo"
        local b: string, c: number = a, 10
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "function_call_with_singletons")
{
    CheckResult result = check(R"(
        function f(a: true, b: "foo") end
        f(true, "foo")
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "function_call_with_singletons_mismatch")
{
    CheckResult result = check(R"(
        function f(a: true, b: "foo") end
        f(true, "bar")
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);
    CHECK_EQ("Expected this to be '\"foo\"', but got '\"bar\"'", toString(result.errors[0]));
}

TEST_CASE_FIXTURE(Fixture, "overloaded_function_call_with_singletons")
{
    CheckResult result = check(R"(
        function f(a, b) end
        local g : ((true, string) -> ()) & ((false, number) -> ()) = (f::any)
        g(true, "foo")
        g(false, 37)
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "overloaded_function_resolution_singleton_parameters")
{
    CheckResult result = check(R"(
        type A = ("A") -> string
        type B = ("B") -> number

        local function foo(f: A & B)
            return f("A"), f("B")
        end
    )");
    LUAU_REQUIRE_NO_ERRORS(result);
    TypeId t = requireType("foo");
    const FunctionType* fooType = get<FunctionType>(requireType("foo"));
    REQUIRE(fooType != nullptr);

    CHECK(toString(t) == "(((\"A\") -> string) & ((\"B\") -> number)) -> (string, number)");
}

TEST_CASE_FIXTURE(Fixture, "overloaded_function_call_with_singletons_mismatch")
{
    DOES_NOT_PASS_NEW_SOLVER_GUARD();

    CheckResult result = check(R"(
        function f(g: ((true, string) -> ()) & ((false, number) -> ()))
            g(true, 37)
        end
    )");

    LUAU_REQUIRE_ERROR_COUNT(2, result);
    if (!FFlag::DebugLuauForceOldSolver)
    {
        CHECK_EQ("None of the overloads for function that accept 2 arguments are compatible.", toString(result.errors[0]));
        CHECK_EQ("Available overloads: (true, string) -> (); and (false, number) -> ()", toString(result.errors[1]));
    }
    else
    {
        CHECK_EQ("Expected this to be 'string', but got 'number'", toString(result.errors[0]));
        CHECK_EQ("Other overloads are also not viable: (false, number) -> ()", toString(result.errors[1]));
    }
}

TEST_CASE_FIXTURE(Fixture, "enums_using_singletons")
{
    CheckResult result = check(R"(
        type MyEnum = "foo" | "bar" | "baz"
        local a : MyEnum = "foo"
        local b : MyEnum = "bar"
        local c : MyEnum = "baz"
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "enums_using_singletons_mismatch")
{
    CheckResult result = check(R"(
        type MyEnum = "foo" | "bar" | "baz"
        local a : MyEnum = "bang"
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);

    if (!FFlag::DebugLuauForceOldSolver)
    {
        // clang-format off
        const std::string expected =
            "Expected this to be '\"bar\" | \"baz\" | \"foo\"', but got '\"bang\"'; \n"
            "this is because \n"
            "	 * the 1st component of the union is `\"foo\"`, and `\"bang\"` is not a subtype of `\"foo\"`\n"
            "	 * the 2nd component of the union is `\"bar\"`, and `\"bang\"` is not a subtype of `\"bar\"`\n"
            "	 * the 3rd component of the union is `\"baz\"`, and `\"bang\"` is not a subtype of `\"baz\"`"
        ;
        // clang-format on

        CHECK_LONG_STRINGS_EQ(expected, toString(result.errors[0]));
    }
    else
        CHECK_EQ(
            "Expected this to be '\"bar\" | \"baz\" | \"foo\"', but got '\"bang\"'; none of the union options are compatible",
            toString(result.errors[0])
        );
}

TEST_CASE_FIXTURE(Fixture, "enums_using_singletons_subtyping")
{
    CheckResult result = check(R"(
        type MyEnum1 = "foo" | "bar"
        type MyEnum2 = MyEnum1 | "baz"
        local a : MyEnum1 = "foo"
        local b : MyEnum2 = a
        local c : string = b
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "tagged_unions_using_singletons")
{
    CheckResult result = check(R"(
        type Dog = { tag: "Dog", howls: boolean }
        type Cat = { tag: "Cat", meows: boolean }
        type Animal = Dog | Cat
        local a : Dog = { tag = "Dog", howls = true }
        local b : Animal = { tag = "Cat", meows = true }
        local c : Animal = a
        c = b
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "tagged_unions_using_singletons_mismatch")
{
    CheckResult result = check(R"(
        type Dog = { tag: "Dog", howls: boolean }
        type Cat = { tag: "Cat", meows: boolean }
        type Animal = Dog | Cat
        local a : Animal = { tag = "Cat", howls = true }
    )");

    LUAU_REQUIRE_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "tagged_unions_immutable_tag")
{
    CheckResult result = check(R"(
        type Dog = { tag: "Dog", howls: boolean }
        type Cat = { tag: "Cat", meows: boolean }
        type Animal = Dog | Cat
        local a: Animal = { tag = "Cat", meows = true }
        a.tag = "Dog"
    )");

    LUAU_REQUIRE_ERRORS(result);

    if (!FFlag::DebugLuauForceOldSolver)
    {
        CannotAssignToNever* tm = get<CannotAssignToNever>(result.errors[0]);
        REQUIRE(tm);

        CHECK(getBuiltins()->stringType == tm->rhsType);
        CHECK(CannotAssignToNever::Reason::PropertyNarrowed == tm->reason);
        REQUIRE(tm->cause.size() == 2);
        CHECK("\"Dog\"" == toString(tm->cause[0]));
        CHECK("\"Cat\"" == toString(tm->cause[1]));
    }
}

TEST_CASE_FIXTURE(Fixture, "table_has_a_boolean")
{
    CheckResult result = check(R"(
        local t={a=1,b=false}
    )");

    if (!FFlag::DebugLuauForceOldSolver)
        CHECK("{ a: number, b: boolean }" == toString(requireType("t"), {true}));
    else
        CHECK("{| a: number, b: boolean |}" == toString(requireType("t"), {true}));
}

TEST_CASE_FIXTURE(Fixture, "table_properties_singleton_strings")
{
    CheckResult result = check(R"(
        --!strict
        type T = {
            ["foo"] : number,
            ["$$bar"] : string,
            baz : boolean
        }
        local t: T =  {
            ["foo"] = 37,
            ["$$bar"] = "hi",
            baz = true
        }
        local a: number = t.foo
        local b: string = t["$$bar"]
        local c: boolean = t.baz
        t.foo = 5
        t["$$bar"] = "lo"
        t.baz = false
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}
TEST_CASE_FIXTURE(Fixture, "table_properties_singleton_strings_mismatch")
{
    CheckResult result = check(R"(
        --!strict
        type T = {
            ["$$bar"] : string,
        }
        local t: T =  {
            ["$$bar"] = "hi",
        }
        t["$$bar"] = 5
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);
    CHECK_EQ("Expected this to be 'string', but got 'number'", toString(result.errors[0]));
}

TEST_CASE_FIXTURE(Fixture, "table_properties_alias_or_parens_is_indexer")
{
    CheckResult result = check(R"(
        --!strict
        type S = "bar"
        type T = {
            [("foo")] : number,
            [S] : string,
        }
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);
    CHECK_EQ("Cannot have more than one table indexer", toString(result.errors[0]));
}

TEST_CASE_FIXTURE(Fixture, "indexer_can_be_union_of_singletons")
{
    if (FFlag::DebugLuauForceOldSolver)
        return;

    CheckResult result = check(R"(
        type Target = "A" | "B"

        type Test = {[Target]: number}

        local test: Test = {}

        test.A = 2
        test.C = 4
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);

    CHECK(8 == result.errors[0].location.begin.line);
}

TEST_CASE_FIXTURE(Fixture, "table_properties_type_error_escapes")
{
    ScopedFastFlag sff{FFlag::DebugLuauForceOldSolver, false};

    CheckResult result = check(R"(
        --!strict
        local x: { ["<>"] : number }
        x = { ["\n"] = 5 }
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);

    const std::string expected =
        R"(Table type '{ ["\n"]: number }' not compatible with type '{ ["<>"]: number }' because the former is missing field '<>')";
    CHECK(expected == toString(result.errors[0]));
}

TEST_CASE_FIXTURE(Fixture, "error_detailed_tagged_union_mismatch_string")
{
    CheckResult result = check(R"(
type Cat = { tag: 'cat', catfood: string }
type Dog = { tag: 'dog', dogfood: string }
type Animal = Cat | Dog

local a: Animal = { tag = 'cat', cafood = 'something' }
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);
    if (!FFlag::DebugLuauForceOldSolver)
        CHECK(
            R"(Table type '{ cafood: string, tag: "cat" }' not compatible with type 'Cat' because the former is missing field 'catfood')" ==
            toString(result.errors[0])
        );
    else
    {
        const std::string expected = R"(Expected this to be 'Cat | Dog', but got 'a'
caused by:
  None of the union options are compatible. For example:
Table type 'a' not compatible with type 'Cat' because the former is missing field 'catfood')";
        CHECK_EQ(expected, toString(result.errors[0]));
    }
}

TEST_CASE_FIXTURE(Fixture, "error_detailed_tagged_union_mismatch_bool")
{
    CheckResult result = check(R"(
type Good = { success: true, result: string }
type Bad = { success: false, error: string }
type Result = Good | Bad

local a: Result = { success = false, result = 'something' }
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);
    if (!FFlag::DebugLuauForceOldSolver)
    {
        CHECK_EQ(
            "Table type '{ result: string, success: false }' not compatible with type 'Bad' because the former is missing field 'error'",
            toString(result.errors[0])
        );
    }
    else
    {
        const std::string expected = R"(Expected this to be 'Bad | Good', but got 'a'
caused by:
  None of the union options are compatible. For example:
Table type 'a' not compatible with type 'Bad' because the former is missing field 'error')";
        CHECK_EQ(expected, toString(result.errors[0]));
    }
}

TEST_CASE_FIXTURE(Fixture, "parametric_tagged_union_alias")
{
    ScopedFastFlag _ {FFlag::DebugLuauForceOldSolver, false};

    CheckResult result = check(R"(
        type Ok<T> = {success: true, result: T}
        type Err<T> = {success: false, error: T}
        type Result<O, E> = Ok<O> | Err<E>

        local a : Result<string, number> = {success = false, result = "hotdogs"}
        -- local b : Result<string, number> = {success = true, result = "hotdogs"}
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, result);

    CHECK_EQ(
        "Table type '{ result: string, success: false }' not compatible with type 'Err<number>' because the former is missing field 'error'",
        toString(result.errors[0])
    );
}

TEST_CASE_FIXTURE(Fixture, "if_then_else_expression_singleton_options")
{
    CheckResult result = check(R"(
type Cat = { tag: 'cat', catfood: string }
type Dog = { tag: 'dog', dogfood: string }
type Animal = Cat | Dog

local a: Animal = if true then { tag = 'cat', catfood = 'something' } else { tag = 'dog', dogfood = 'other' }
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "widen_the_supertype_if_it_is_free_and_subtype_has_singleton")
{
    DOES_NOT_PASS_NEW_SOLVER_GUARD();

    CheckResult result = check(R"(
        local function foo(f, x)
            if x == "hi" then
                f(x)
                f("foo")
            end
        end
    )");

    LUAU_CHECK_NO_ERRORS(result);

    CHECK_EQ(R"("hi")", toString(requireTypeAtPosition({3, 18})));
    // should be <a...>((string) -> a..., string) -> () but needs lower bounds calculation
    CHECK_EQ("<a, b...>((string) -> (b...), a) -> ()", toString(requireType("foo")));
}

TEST_CASE_FIXTURE(Fixture, "return_type_of_f_is_not_widened")
{
    DOES_NOT_PASS_NEW_SOLVER_GUARD();

    CheckResult result = check(R"(
        local function foo(f, x): "hello"? -- anyone there?
            return if x == "hi"
                then f(x)
                else nil
        end
    )");

    LUAU_REQUIRE_NO_ERRORS(result);

    CHECK_EQ(R"("hi")", toString(requireTypeAtPosition({3, 23})));
    CHECK_EQ(R"(<a, b, c...>((string) -> (a, c...), b) -> "hello"?)", toString(requireType("foo")));
    // CHECK_EQ(R"(<a, b...>((string) -> ("hello"?, b...), a) -> "hello"?)", toString(requireType("foo")));
}

TEST_CASE_FIXTURE(Fixture, "widening_happens_almost_everywhere")
{
    CheckResult result = check(R"(
        local foo: "foo" = "foo"
        local copy = foo
    )");

    LUAU_REQUIRE_NO_ERRORS(result);

    if (!FFlag::DebugLuauForceOldSolver)
        CHECK_EQ(R"("foo")", toString(requireType("copy")));
    else
        CHECK_EQ("string", toString(requireType("copy")));
}

TEST_CASE_FIXTURE(Fixture, "widening_happens_almost_everywhere_except_for_tables")
{
    CheckResult result = check(R"(
        type Cat = {tag: "Cat", meows: boolean}
        type Dog = {tag: "Dog", barks: boolean}
        type Animal = Cat | Dog

        local function f(tag: "Cat" | "Dog"): Animal?
            if tag == "Cat" then
                local result = {tag = tag, meows = true}
                return result
            elseif tag == "Dog" then
                local result = {tag = tag, barks = true}
                return result
            else
                return nil
            end
        end
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "functions_are_not_to_be_widened")
{
    CheckResult result = check(R"(
        local function foo(my_enum: "A" | "B") end
    )");

    LUAU_REQUIRE_NO_ERRORS(result);

    CHECK_EQ(R"(("A" | "B") -> ())", toString(requireType("foo")));
}

TEST_CASE_FIXTURE(Fixture, "indexing_on_string_singletons")
{
    CheckResult result = check(R"(
        local a: string = "hi"
        if a == "hi" then
            local x = a:byte()
        end
    )");

    LUAU_REQUIRE_NO_ERRORS(result);

    CHECK_EQ(R"("hi")", toString(requireTypeAtPosition({3, 22})));
}

TEST_CASE_FIXTURE(Fixture, "indexing_on_union_of_string_singletons")
{
    CheckResult result = check(R"(
        local a: string = "hi"
        if a == "hi" or a == "bye" then
            local x = a:byte()
        end
    )");

    LUAU_REQUIRE_NO_ERRORS(result);

    CHECK_EQ(R"("bye" | "hi")", toString(requireTypeAtPosition({3, 22})));
}

TEST_CASE_FIXTURE(Fixture, "taking_the_length_of_string_singleton")
{
    CheckResult result = check(R"(
        local a: string = "hi"
        if a == "hi" then
            local x = #a
        end
    )");

    LUAU_REQUIRE_NO_ERRORS(result);

    CHECK_EQ(R"("hi")", toString(requireTypeAtPosition({3, 23})));
}

TEST_CASE_FIXTURE(Fixture, "taking_the_length_of_union_of_string_singleton")
{
    CheckResult result = check(R"(
        local a: string = "hi"
        if a == "hi" or a == "bye" then
            local x = #a
        end
    )");

    LUAU_REQUIRE_NO_ERRORS(result);

    CHECK_EQ(R"("bye" | "hi")", toString(requireTypeAtPosition({3, 23})));
}

TEST_CASE_FIXTURE(Fixture, "no_widening_from_callsites")
{
    CheckResult result = check(R"(
        type Direction = "North" | "East" | "West" | "South"

        local function direction(): Direction
            return "North"
        end

        local d: Direction = direction()
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(BuiltinsFixture, "singletons_stick_around_under_assignment")
{
    CheckResult result = check(R"(
        type Foo = {
            kind: "Foo",
        }

        local foo = (nil :: any) :: Foo

        print(foo.kind == "Bar") -- type of equality refines to `false`
        local kind = foo.kind
        print(kind == "Bar") -- type of equality refines to `false`
    )");

    if (!FFlag::DebugLuauForceOldSolver)
        LUAU_REQUIRE_NO_ERRORS(result);
    else
        LUAU_REQUIRE_ERROR_COUNT(1, result);
}

TEST_CASE_FIXTURE(Fixture, "tagged_union_in_ternary")
{
    LUAU_REQUIRE_NO_ERRORS(check(R"(
        type Result = { type: "ok", value: unknown } | { type: "error" }

        local function coinflip(): boolean return true end

        local function readFromDB(): Result
            return if coinflip() then { type = "ok", value = 42 } else { type = "error" }
        end
    )"));
}

TEST_CASE_FIXTURE(Fixture, "table_literal_with_singleton_union_values")
{
    CheckResult result = check(R"(
        local t1: {[string]: "a" | "b"} = { a = "a", b = "b" }
        local t2: {[string]: "a" | true} = { a = "a", b = true }
        local t3: {[string]: "a" | nil} = { a = "a" }
    )");

    LUAU_REQUIRE_NO_ERRORS(result);
}

TEST_CASE_FIXTURE(Fixture, "singleton_type_mismatch_via_variable")
{
    CheckResult result = check(R"(
        local c = "c"
        local x: "a" = c
        local y: "a" | "b" = c
        local z: "a"? = c
        local w: "a" | "b" = "c"
    )");

    LUAU_REQUIRE_ERROR_COUNT(4, result);

    REQUIRE(get<TypeMismatch>(result.errors[0]));
    REQUIRE(get<TypeMismatch>(result.errors[1]));
    REQUIRE(get<TypeMismatch>(result.errors[2]));
    REQUIRE(get<TypeMismatch>(result.errors[3]));
}

TEST_CASE_FIXTURE(Fixture, "cli_163481_any_indexer_pushes_type")
{
    LUAU_REQUIRE_NO_ERRORS(check(R"(
        --!strict

        type test = "A"
        type test2 = "A"|"B"|"C"

        local t: { [any]: test } = { A = "A" }

        local t2: { [any]: test2 } = {
            A = "A",
            B = "B",
            C = "C"
        }
    )"));
}

TEST_CASE_FIXTURE(Fixture, "oss_2010")
{
    ScopedFastFlag _{FFlag::DebugLuauForceOldSolver, false};

    LUAU_REQUIRE_NO_ERRORS(check(R"(
        local function foo<T>(my_enum: "" | T): T
            return my_enum :: T
        end

        local var = foo("meow")
    )"));

    CHECK_EQ("\"meow\"", toString(requireType("var")));
}

TEST_CASE_FIXTURE(Fixture, "oss_1773")
{
    ScopedFastFlag _{FFlag::DebugLuauForceOldSolver, false};

    LUAU_REQUIRE_NO_ERRORS(check(R"(
        --!strict

        export type T = "foo" | "bar" | "toto"

        local object: T = "foo"

        local getOpposite: {[T]: T} = {
            ["foo"] = "bar",
            ["bar"] = "toto",
            ["toto"] = "foo"
        }

        local function hello()
            local x = getOpposite[object]

            if x then
                object = x
            end
        end
    )"));
}

TEST_CASE_FIXTURE(Fixture, "bidirectionally_infer_indexers_errored")
{
    ScopedFastFlag _{FFlag::DebugLuauForceOldSolver, false};

    CheckResult result = check(R"(
        --!strict

        export type T = "foo" | "bar" | "toto"

        local getOpposite: { [number]: T } = {
            ["foo"] = "bar",
            ["bar"] = "toto",
            ["toto"] = "foo"
        }
    )");

    LUAU_REQUIRE_ERROR_COUNT(3, result);

    for (const auto& e : result.errors)
        CHECK(get<TypeMismatch>(e));
}

TEST_CASE_FIXTURE(Fixture, "oss_2018")
{
    LUAU_REQUIRE_NO_ERRORS(check(R"(
        local rule: { rule: "AppendTextComment" } | { rule: "Other" } = { rule = "AppendTextComment" }
    )"));
}

TEST_CASE_FIXTURE(Fixture, "oss_2010_but_with_booleans")
{
    ScopedFastFlag sffs[] = {
        {FFlag::DebugLuauForceOldSolver, false},
        {FFlag::LuauReplacerRespectsReboundGenerics, true},
        {FFlag::LuauOverloadGetsInstantiated2, true},
    };

    CheckResult results = check(R"(
        local function foo<T>(my_enum: true | T): T
            return my_enum :: T
        end

        local function bar<T>(my_enum: true & T): T
            return my_enum :: T
        end

        local var1 = foo(true)
        local var2 = foo(false)

        local var3 = bar(true)
        local var4 = bar(false)
    )");

    LUAU_REQUIRE_ERROR_COUNT(1, results);
    auto err = get<TypeMismatch>(results.errors[0]);
    REQUIRE(err);
    // This is a little clowny, it should probably be `never` and we
    // should complain in a different manner, but it's an error, and it
    // is definitely true that `false </: false & true`
    CHECK_EQ("false & true", toString(err->wantedType));
    CHECK_EQ("false", toString(err->givenType));

    // FIXME: That one seems arguably correct.
    CHECK_EQ("unknown", toString(requireType("var1")));
    CHECK_EQ("false", toString(requireType("var2")));
    CHECK_EQ("true", toString(requireType("var3")));
    CHECK_EQ("false", toString(requireType("var4")));
}

TEST_CASE_FIXTURE(Fixture, "cli_184125")
{
    ScopedFastFlag _{FFlag::DebugLuauForceOldSolver, false};

    LUAU_REQUIRE_NO_ERRORS(check(R"(
        type MyTypeA = {Value: true}
        type MyTypeB = {Value: false}

        local function Func(input: number) : (MyTypeA | MyTypeB)
            if input == 1 then
                return {Value = true}
            else
                return {Value = false}
            end
        end
    )"));
}


TEST_SUITE_END();