TypeScript/tests/cases/compiler/overloadresolutionWithConstraintCheckingDeferred.ts

22 lines
687 B
TypeScript

interface A { x }
interface B { x; y }
interface C { z }
interface D { q }
class G<T extends A> {
constructor(x: T) { }
}
declare function foo(arg: (x: D) => number): string;
declare function foo(arg: (x: C) => any): string;
declare function foo(arg: (x: B) => any): number;
var result: number = foo(x => new G(x)); // x has type D, new G(x) fails, so first overload is picked.
var result2: number = foo(x => new G<typeof x>(x)); // x has type D, new G(x) fails, so first overload is picked.
var result3: string = foo(x => { // x has type D
var y: G<typeof x>; // error that D does not satisfy constraint, y is of type G<D>, entire call to foo is an error
return y;
});