Rule proposal: prefer querySelector generic vs type cast

[bschlenk]

Before You File a Proposal Please Confirm You Have Done The Following...

• I have searched for related issues and found none that match my proposal.
• I have searched the current rule list and found no rules that match my proposal.
• I have read the FAQ and my problem is not listed.

My proposal is suitable for this project

• My proposal specifically checks TypeScript syntax, or it proposes a check that requires type information to be accurate.
• My proposal is not a "formatting rule"; meaning it does not just enforce how code is formatted (whitespace, brace placement, etc).
• I believe my proposal would be useful to the broader TypeScript community (meaning it is not a niche proposal).

Description

#9007 was closed before I could comment there. I wasn't aware that querySelector took a generic argument. It'd be nice if there was a lint rule that caught

document.querySelector('something') as HTMLElement

and recommended changing it to

document.querySelector<HTMLElement>('something')

And maybe this could be done in a more generic way, possibly catching all functions that accept a generic but are being cast instead?

Fail Cases

document.querySelector('div') as HTMLDivElement

Pass Cases

document.querySelector<HTMLDivElement>('div')

Additional Info

It would help with these duplicates if this was enabled in the recommended ruleset

#8388, #7207, #5808, #5359, #528

[Josh-Cena]

Doesn't no-unnecessary-type-assertion do exactly that? Why do we need a specific rule to report this pattern? (Note that even if we do, it would not be specific to querySelector, but functions with the signature f<T>(...args): T in general.)

I do think we should add this pattern to the docs, and/or improve the error message, but I'm not sure why any new feature is needed.

[Josh-Cena]

Closing because this is exactly what no-unnecessary-type-assertion does. #6951 will improve the error message