Bind and Apply calls are not checked against all function overloads

[rkirov]

TypeScript Version: 3.8.2-dev.201xxxxx

Search Terms: call apply overload

Code

interface Fn {
  (x: string): void;
  (x: number, y: boolean): void;
}

declare const f: Fn;
f(''); // ok
f.call(null, ''); // error 
f.apply(null, ['']); // error

Expected behavior:
No type errors as f('') is equivalent to f.call(null, '') and f.apply(null, ['']).

Actual behavior:
Type errors on f.call(null, '') and f.apply(null, ['']).

Playground Link: Playground Link

Related Issues:

[RyanCavanaugh]

The call/apply mechanics end up going through the arg-to-tuple process, which isn't capable of handling overloads. Since your return types match, you can write

interface Fn {
  (...args: [string] | [number, boolean]): void;
}

declare const f: Fn;
f(''); // ok
f.call(null, ''); // ok
f.apply(null, ['']); // ok

instead to avoid the error

[rkirov]

Thanks for explaining, this is not a major issue for us, just wanted to check if it can use a small bug fix, or a known design limitation. Feel free to close this issue.