tests/cases/conformance/es6/templates/taggedTemplateStringsTypeArgumentInferenceES6.ts(63,11): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly. Type argument candidate 'string' is not a valid type argument because it is not a supertype of candidate 'number'. tests/cases/conformance/es6/templates/taggedTemplateStringsTypeArgumentInferenceES6.ts(76,11): error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly. Type argument candidate '{ x: number; z: Date; }' is not a valid type argument because it is not a supertype of candidate '{ x: number; y: string; }'. ==== tests/cases/conformance/es6/templates/taggedTemplateStringsTypeArgumentInferenceES6.ts (2 errors) ==== // Generic tag with one parameter function noParams(n: T) { } noParams ``; // Generic tag with parameter which does not use type parameter function noGenericParams(n: string[]) { } noGenericParams ``; // Generic tag with multiple type parameters and only one used in parameter type annotation function someGenerics1a(n: T, m: number) { } someGenerics1a `${3}`; function someGenerics1b(n: string[], m: U) { } someGenerics1b `${3}`; // Generic tag with argument of function type whose parameter is of type parameter type function someGenerics2a(strs: string[], n: (x: T) => void) { } someGenerics2a `${(n: string) => n}`; function someGenerics2b(strs: string[], n: (x: T, y: U) => void) { } someGenerics2b `${ (n: string, x: number) => n }`; // Generic tag with argument of function type whose parameter is not of type parameter type but body/return type uses type parameter function someGenerics3(strs: string[], producer: () => T) { } someGenerics3 `${() => ''}`; someGenerics3 `${() => undefined}`; someGenerics3 `${() => 3}`; // 2 parameter generic tag with argument 1 of type parameter type and argument 2 of function type whose parameter is of type parameter type function someGenerics4(strs: string[], n: T, f: (x: U) => void) { } someGenerics4 `${4}${ () => null }`; someGenerics4 `${''}${ () => 3 }`; someGenerics4 `${ null }${ null }`; // 2 parameter generic tag with argument 2 of type parameter type and argument 1 of function type whose parameter is of type parameter type function someGenerics5(strs: string[], n: T, f: (x: U) => void) { } someGenerics5 `${ 4 } ${ () => null }`; someGenerics5 `${ '' }${ () => 3 }`; someGenerics5 `${null}${null}`; // Generic tag with multiple arguments of function types that each have parameters of the same generic type function someGenerics6(strs: string[], a: (a: A) => A, b: (b: A) => A, c: (c: A) => A) { } someGenerics6 `${ n => n }${ n => n}${ n => n}`; someGenerics6 `${ n => n }${ n => n}${ n => n}`; someGenerics6 `${ (n: number) => n }${ (n: number) => n }${ (n: number) => n }`; // Generic tag with multiple arguments of function types that each have parameters of different generic type function someGenerics7(strs: string[], a: (a: A) => A, b: (b: B) => B, c: (c: C) => C) { } someGenerics7 `${ n => n }${ n => n }${ n => n }`; someGenerics7 `${ n => n }${ n => n }${ n => n }`; someGenerics7 `${(n: number) => n}${ (n: string) => n}${ (n: number) => n}`; // Generic tag with argument of generic function type function someGenerics8(strs: string[], n: T): T { return n; } var x = someGenerics8 `${ someGenerics7 }`; x `${null}${null}${null}`; // Generic tag with multiple parameters of generic type passed arguments with no best common type function someGenerics9(strs: string[], a: T, b: T, c: T): T { return null; } var a9a = someGenerics9 `${ '' }${ 0 }${ [] }`; ~~~~~~~~~~~~~ !!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly. !!! error TS2453: Type argument candidate 'string' is not a valid type argument because it is not a supertype of candidate 'number'. var a9a: {}; // Generic tag with multiple parameters of generic type passed arguments with multiple best common types interface A91 { x: number; y?: string; } interface A92 { x: number; z?: Date; } var a9e = someGenerics9 `${ undefined }${ { x: 6, z: new Date() } }${ { x: 6, y: '' } }`; ~~~~~~~~~~~~~ !!! error TS2453: The type argument for type parameter 'T' cannot be inferred from the usage. Consider specifying the type arguments explicitly. !!! error TS2453: Type argument candidate '{ x: number; z: Date; }' is not a valid type argument because it is not a supertype of candidate '{ x: number; y: string; }'. var a9e: {}; // Generic tag with multiple parameters of generic type passed arguments with a single best common type var a9d = someGenerics9 `${ { x: 3 }}${ { x: 6 }}${ { x: 6 } }`; var a9d: { x: number; }; // Generic tag with multiple parameters of generic type where one argument is of type 'any' var anyVar: any; var a = someGenerics9 `${ 7 }${ anyVar }${ 4 }`; var a: any; // Generic tag with multiple parameters of generic type where one argument is [] and the other is not 'any' var arr = someGenerics9 `${ [] }${ null }${ undefined }`; var arr: any[];