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

• I havesearched for related issues and found none that match my proposal.
• I have searched thecurrent rule list and found no rules that match my proposal.
• I haveread 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

#6211 shows a use ofarray.at(-1), as a cleaner equivalent toarray[array.length - 1].https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/at

Proposal: let's add a typed lint rule that, when it sees something likearray[array.length - 1] on an Array-typed value, proposes fixing toarray.at(-1)?

Fail Cases

declareconstarray:string[];array[array.length-1];

Pass Cases

declareconstarray:string[];array.at(-1);// [] indices are reasonablearray[0];// Don't look through functionsconstgetArray=()=>array;getArray()[getArray().length-1];

Additional Info

Reference for an existing similar rule:https://typescript-eslint.io/rules/prefer-includes.

I don't think we should enable this inrecommended orstrict configs until we only support Node versions that include.at. Per#6396 this wouldn't make sense for users who compile to Node 14 and don't include a polyfill.