Warn against bad JS functions

[chenglou]

Inspired by #2666

JavaScript array's sorting is confusing since it compares using the stringified value. We can put a warning on that external (Js.Array.sortInPlace) to discourage its usage. I'm wondering which other Js helpers we should discourage, aka what JS functions should we discourage even if we're writing in pure JS?

• sort
• isNaN (use Number.isNaN instead)
• parseInt (we can warn and ask folks to use the version with the radix instead)
• ?

Basically, we can piggy back on ocaml's warning system as a linter. It's interesting that writing in BS (+ Reason) might allow you to write better JS here.

[cullophid]

eval might be a good choice

[RReverser]

Even version with the radix for parseInt should be discouraged. It's pretty much always a footgun since it silenty ignores trailing non-numeric chars instead of reporting an error or returning NaN to indicate parsing failure.

[Dilski]

Non-strict equality from js (== and !=)?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.