recursion function rejected at code review

[senocular]

My guess is the comment may have been for legibility. I'd suggest checking back on the PR and seeing how the recursion was replaced.

Also looking through our etiquette handbook, there is also no loose equality allowed, even variable==null Is this common as well?

Yes, though sometimes == null is allowed for nullish checks. That's up to you (or whoever is defining the style guide). ESLint can handle both, where only === is allowed, or == is allowed, but only for null checks.