// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details #include "Fixture.h" #include "doctest.h" using namespace Luau; LUAU_FASTFLAG(DebugLuauDeferredConstraintResolution); 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, "bool_singletons_mismatch") { CheckResult result = check(R"( local a: true = false )"); LUAU_REQUIRE_ERROR_COUNT(1, result); CHECK_EQ("Type 'false' could not be converted into 'true'", 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("Type '\"bar\"' could not be converted into '\"foo\"'", 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"(Type '"\000\r"' could not be converted into '"\n"')", 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("Type '\"bar\"' could not be converted into '\"foo\"'", 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_call_with_singletons_mismatch") { CheckResult result = check(R"( function f(g: ((true, string) -> ()) & ((false, number) -> ())) g(true, 37) end )"); LUAU_REQUIRE_ERROR_COUNT(2, result); if (FFlag::DebugLuauDeferredConstraintResolution) { 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("Type 'number' could not be converted into 'string'", 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); CHECK_EQ("Type '\"bang\"' could not be converted into '\"bar\" | \"baz\" | \"foo\"'; 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); } TEST_CASE_FIXTURE(Fixture, "table_has_a_boolean") { CheckResult result = check(R"( local t={a=1,b=false} )"); 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("Type 'number' could not be converted into 'string'", 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, "table_properties_type_error_escapes") { CheckResult result = check(R"( --!strict local x: { ["<>"] : number } x = { ["\n"] = 5 } )"); LUAU_REQUIRE_ERROR_COUNT(1, result); CHECK_EQ(R"(Table type '{ ["\n"]: number }' not compatible with type '{| ["<>"]: number |}' because the former is missing field '<>')", 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); const std::string expected = R"(Type 'a' could not be converted into 'Cat | Dog' 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); const std::string expected = R"(Type 'a' could not be converted into 'Bad | Good' 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 sff[] = { {FFlag::DebugLuauDeferredConstraintResolution, true}, }; CheckResult result = check(R"( type Ok = {success: true, result: T} type Err = {success: false, error: T} type Result = Ok | Err local a : Result = {success = false, result = "hotdogs"} local b : Result = {success = true, result = "hotdogs"} )"); LUAU_REQUIRE_ERROR_COUNT(1, result); const std::string expectedError = "Type 'a' could not be converted into 'Err | Ok'; type a (a) is not a subtype of Err | Ok[1] (Err)\n" "\ttype a[\"success\"] (false) is not exactly Err | Ok[0][\"success\"] (true)"; CHECK(toString(result.errors[0]) == expectedError); } 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") { CheckResult result = check(R"( local function foo(f, x) if x == "hi" then f(x) f("foo") end end )"); LUAU_REQUIRE_NO_ERRORS(result); CHECK_EQ(R"("hi")", toString(requireTypeAtPosition({3, 18}))); // should be ((string) -> a..., string) -> () but needs lower bounds calculation CHECK_EQ("((string) -> (b...), a) -> ()", toString(requireType("foo"))); } TEST_CASE_FIXTURE(Fixture, "return_type_of_f_is_not_widened") { 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"(((string) -> (a, c...), b) -> "hello"?)", toString(requireType("foo"))); // CHECK_EQ(R"(((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::DebugLuauDeferredConstraintResolution) 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_SUITE_END();