.toBeCallableWith() does not work with generic functions or overloads #50
Description
If a generic function is declared like this:
export declare function foo <T>(x: T, y: T): T;The .toBeCallableWith() matcher fails:
expectTypeOf(foo).toBeCallableWith(123, "123"); // no error reported
foo(123, "123");
~~~~~ Argument of type '"123"' is not assignable to parameter of type '123'.Testing an overloaded function:
export declare const foo: {
(x: string, y: string): string;
(x: number, y: number): number;
};Does not work either:
expectTypeOf(foo).toBeCallableWith("abc", "efg");
~~~~~ Argument of type 'string' is not assignable to parameter of type 'number'.
expectTypeOf(foo).toBeCallableWith(123, 456);
foo("abc", "efg"); // but all is good here
foo(123, 456);Hm.. If a simple foo() does the job (and does it better!), what is the purpose of .toBeCallableWith()? I mean, .toEqualTypeOf() works perfectly in both of the cases I mentioned above:
expectTypeOf(foo("abc", "efg")).toEqualTypeOf<string>();
expectTypeOf(foo(123, 456)).toEqualTypeOf<number>();.not.toBeCallableWith() could handle a check which .toEqualTypeOf() cannot and would be more useful than // @ts-expect-error. Unfortunately it is not implemented at the moment.