tests/cases/conformance/es6/templates/taggedTemplateStringsWithOverloadResolution3_ES6.ts(9,9): error TS2769: No overload matches this call. Overload 1 of 2, '(strs: TemplateStringsArray, s: string): string', gave the following error. Argument of type '{}' is not assignable to parameter of type 'string'. Overload 2 of 2, '(strs: TemplateStringsArray, n: number): number', gave the following error. Argument of type '{}' is not assignable to parameter of type 'number'. tests/cases/conformance/es6/templates/taggedTemplateStringsWithOverloadResolution3_ES6.ts(18,4): error TS2339: Property 'foo' does not exist on type 'Date'. tests/cases/conformance/es6/templates/taggedTemplateStringsWithOverloadResolution3_ES6.ts(44,1): error TS2554: Expected 2-4 arguments, but got 1. tests/cases/conformance/es6/templates/taggedTemplateStringsWithOverloadResolution3_ES6.ts(62,9): error TS2769: No overload matches this call. Overload 1 of 3, '(strs: TemplateStringsArray, n: string, m: any): any', gave the following error. Argument of type 'boolean' is not assignable to parameter of type 'string'. Overload 2 of 3, '(strs: TemplateStringsArray, n: number, m: any): any', gave the following error. Argument of type 'boolean' is not assignable to parameter of type 'number'. tests/cases/conformance/es6/templates/taggedTemplateStringsWithOverloadResolution3_ES6.ts(63,18): error TS2769: No overload matches this call. Overload 1 of 3, '(strs: TemplateStringsArray, n: any, m: number): any', gave the following error. Argument of type 'boolean' is not assignable to parameter of type 'number'. Overload 2 of 3, '(strs: TemplateStringsArray, n: any, m: string): any', gave the following error. Argument of type 'boolean' is not assignable to parameter of type 'string'. tests/cases/conformance/es6/templates/taggedTemplateStringsWithOverloadResolution3_ES6.ts(69,18): error TS2551: Property 'toFixed' does not exist on type 'string'. Did you mean 'fixed'? ==== tests/cases/conformance/es6/templates/taggedTemplateStringsWithOverloadResolution3_ES6.ts (6 errors) ==== // Ambiguous call picks the first overload in declaration order function fn1(strs: TemplateStringsArray, s: string): string; function fn1(strs: TemplateStringsArray, n: number): number; function fn1() { return null; } var s: string = fn1 `${ undefined }`; // No candidate overloads found fn1 `${ {} }`; // Error ~~ !!! error TS2769: No overload matches this call. !!! error TS2769: Overload 1 of 2, '(strs: TemplateStringsArray, s: string): string', gave the following error. !!! error TS2769: Argument of type '{}' is not assignable to parameter of type 'string'. !!! error TS2769: Overload 2 of 2, '(strs: TemplateStringsArray, n: number): number', gave the following error. !!! error TS2769: Argument of type '{}' is not assignable to parameter of type 'number'. function fn2(strs: TemplateStringsArray, s: string, n: number): number; function fn2(strs: TemplateStringsArray, n: number, t: T): T; function fn2() { return undefined; } var d1: Date = fn2 `${ 0 }${ undefined }`; // contextually typed var d2 = fn2 `${ 0 }${ undefined }`; // any d1.foo(); // error ~~~ !!! error TS2339: Property 'foo' does not exist on type 'Date'. d2(); // no error (typed as any) // Generic and non-generic overload where generic overload is the only candidate fn2 `${ 0 }${ '' }`; // OK // Generic and non-generic overload where non-generic overload is the only candidate fn2 `${ '' }${ 0 }`; // OK // Generic overloads with differing arity function fn3(strs: TemplateStringsArray, n: T): string; function fn3(strs: TemplateStringsArray, s: string, t: T, u: U): U; function fn3(strs: TemplateStringsArray, v: V, u: U, t: T): number; function fn3() { return null; } var s = fn3 `${ 3 }`; var s = fn3 `${'' }${ 3 }${ '' }`; var n = fn3 `${ 5 }${ 5 }${ 5 }`; var n: number; // Generic overloads with differing arity tagging with arguments matching each overload type parameter count var s = fn3 `${ 4 }` var s = fn3 `${ '' }${ '' }${ '' }`; var n = fn3 `${ '' }${ '' }${ 3 }`; // Generic overloads with differing arity tagging with argument count that doesn't match any overload fn3 ``; // Error ~~~~~~ !!! error TS2554: Expected 2-4 arguments, but got 1. !!! related TS6210 tests/cases/conformance/es6/templates/taggedTemplateStringsWithOverloadResolution3_ES6.ts:28:45: An argument for 'n' was not provided. // Generic overloads with constraints function fn4(strs: TemplateStringsArray, n: T, m: U); function fn4(strs: TemplateStringsArray, n: T, m: U); function fn4(strs: TemplateStringsArray) function fn4() { } // Generic overloads with constraints tagged with types that satisfy the constraints fn4 `${ '' }${ 3 }`; fn4 `${ 3 }${ '' }`; fn4 `${ 3 }${ undefined }`; fn4 `${ '' }${ null }`; // Generic overloads with constraints called with type arguments that do not satisfy the constraints fn4 `${ null }${ null }`; // Error // Generic overloads with constraints called without type arguments but with types that do not satisfy the constraints fn4 `${ true }${ null }`; ~~~~ !!! error TS2769: No overload matches this call. !!! error TS2769: Overload 1 of 3, '(strs: TemplateStringsArray, n: string, m: any): any', gave the following error. !!! error TS2769: Argument of type 'boolean' is not assignable to parameter of type 'string'. !!! error TS2769: Overload 2 of 3, '(strs: TemplateStringsArray, n: number, m: any): any', gave the following error. !!! error TS2769: Argument of type 'boolean' is not assignable to parameter of type 'number'. fn4 `${ null }${ true }`; ~~~~ !!! error TS2769: No overload matches this call. !!! error TS2769: Overload 1 of 3, '(strs: TemplateStringsArray, n: any, m: number): any', gave the following error. !!! error TS2769: Argument of type 'boolean' is not assignable to parameter of type 'number'. !!! error TS2769: Overload 2 of 3, '(strs: TemplateStringsArray, n: any, m: string): any', gave the following error. !!! error TS2769: Argument of type 'boolean' is not assignable to parameter of type 'string'. // Non - generic overloads where contextual typing of function arguments has errors function fn5(strs: TemplateStringsArray, f: (n: string) => void): string; function fn5(strs: TemplateStringsArray, f: (n: number) => void): number; function fn5() { return undefined; } fn5 `${ (n) => n.toFixed() }`; // will error; 'n' should have type 'string'. ~~~~~~~ !!! error TS2551: Property 'toFixed' does not exist on type 'string'. Did you mean 'fixed'? !!! related TS2728 /.ts/lib.es2015.core.d.ts:485:5: 'fixed' is declared here. fn5 `${ (n) => n.substr(0) }`;