New Rule: prefer using `.at()`

Rule details

prefer using .at() to all the basic indexable classes (Array, String, TypedArray)

Related ECMAScript feature

https://github.com/tc39/proposal-relative-indexing-method

What type of rule is this?

Suggests an alternate way of doing something

Example code

incorrect examples:

var arr = [....];
var last = arr[arr.length - 1];

correct examples:

var arr = [....];
var last = arr.at(-1);

Why should this rule be in the core instead of a plugin?

it’s not platform-specific.

Participation

• I am willing to submit a pull request to implement this rule.

Additional comments

it has been stage-4.

[bmish]

Unicorn rule for reference: unicorn/prefer-at

[nzakas]

I think this rule without types cannot be safely used in all environments, and therefore doesn’t qualify for a core rule.

I agree. In general, instance method related rules are problematic because type information is required to be safe.

Given that there’s already a plugin rule filling this gap, I think we should decline.