Rule proposal: Ban method override type narrowing about typescript-eslint HOT 3 OPEN

Huh. Without really having thought about this, my initial impression is that I would have thought that TS would allow subclasses to accept wider parameters and return narrower return types. But if I understand correctly it allows only narrower types both for parameters and return values, is that right?

Currently TS supports both wider and narrower parameter types. I don't think either should be allowed

from typescript-eslint.

Subclasses accepting wider parameters is safe and idiomatic. Banning it will make some OOP patterns needlessly complicated. Subclasses accepting narrower parameters is because methods are fundamentally unsafe: see https://typescript-eslint.io/rules/method-signature-style/

I'm slightly in favor of such a rule that bans overriding methods accepting narrower input.

from typescript-eslint.

Huh. Without really having thought about this, my initial impression is that I would have thought that TS would allow subclasses to accept wider parameters and return narrower return types. But if I understand correctly it allows only narrower types both for parameters and return values, is that right?

from typescript-eslint.