Enable eslint rule no-extra-boolean-cast

[Jake Bailey (jakebailey)]

Follow-up to #54693.

This is probably more for discussion; these extra !! are redundant and not obviously wrong, but, it's probably a fine cleanup.

[Jake Bailey (jakebailey)]

Aha, well, clearly I expected --fix to not cause any new errors, and yet here we are; seems like this lint rule isn't always accurate.

[Bruce Pascoe (fatcerberus)]

Looking at the diff I see a few places where it does stuff like !!foo.bar ? foo.bar() : defVal - I like the !! there because it makes it clear you’re checking for method existence and didn’t just accidentally forget the parens on a method call.

Also I thought TS itself had a check that flags stuff like if (obj.method) {} as an error (”Did you mean to call this function?”), likewise for promises without an await, so these might not always be redundant in a way that a linter can detect.

[Jake Bailey (jakebailey)]

I don't disagree; I'll probably just disable this rule instead.

We do have those checks, though they only apply in certain circumstances.

[Jake Bailey (jakebailey)]

I'm opting to disable this in #55136.