tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(3,10): error TS2381: A signature with an implementation cannot use a string literal type. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(4,18): error TS2381: A signature with an implementation cannot use a string literal type. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(5,10): error TS2381: A signature with an implementation cannot use a string literal type. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(8,5): error TS2381: A signature with an implementation cannot use a string literal type. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(12,5): error TS2382: Specialized overload signature is not assignable to any non-specialized signature. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(13,5): error TS2382: Specialized overload signature is not assignable to any non-specialized signature. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(17,5): error TS2382: Specialized overload signature is not assignable to any non-specialized signature. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(18,5): error TS2382: Specialized overload signature is not assignable to any non-specialized signature. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(22,5): error TS2381: A signature with an implementation cannot use a string literal type. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(23,17): error TS2381: A signature with an implementation cannot use a string literal type. tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts(24,8): error TS2381: A signature with an implementation cannot use a string literal type. ==== tests/cases/conformance/types/objectTypeLiteral/callSignatures/stringLiteralTypesInImplementationSignatures.ts (11 errors) ==== // String literal types are only valid in overload signatures function foo(x: 'hi') { } ~~~ !!! error TS2381: A signature with an implementation cannot use a string literal type. var f = function foo(x: 'hi') { } ~~~ !!! error TS2381: A signature with an implementation cannot use a string literal type. var f2 = (x: 'hi', y: 'hi') => { } ~~~~~~~~~~~~~~~~~~~~~~~~~ !!! error TS2381: A signature with an implementation cannot use a string literal type. class C { foo(x: 'hi') { } ~~~~~~~~~~~~~~~~ !!! error TS2381: A signature with an implementation cannot use a string literal type. } interface I { (x: 'hi'); ~~~~~~~~~~ !!! error TS2382: Specialized overload signature is not assignable to any non-specialized signature. foo(x: 'hi', y: 'hi'); ~~~~~~~~~~~~~~~~~~~~~~ !!! error TS2382: Specialized overload signature is not assignable to any non-specialized signature. } var a: { (x: 'hi'); ~~~~~~~~~~ !!! error TS2382: Specialized overload signature is not assignable to any non-specialized signature. foo(x: 'hi'); ~~~~~~~~~~~~~ !!! error TS2382: Specialized overload signature is not assignable to any non-specialized signature. } var b = { foo(x: 'hi') { }, ~~~~~~~~~~~~~~~~ !!! error TS2381: A signature with an implementation cannot use a string literal type. a: function foo(x: 'hi', y: 'hi') { }, ~~~ !!! error TS2381: A signature with an implementation cannot use a string literal type. b: (x: 'hi') => { } ~~~~~~~~~~~~~~~~ !!! error TS2381: A signature with an implementation cannot use a string literal type. }