comma-dangle inside promises is weird

Sadly, .then() can accept multiple arguments (the second being the catch function). But none should really use .then() with more than one argument (right? 😝 )

In this example eslint complains about comma-dangle rule:

y.then(x => x
  .replace('asdasdsdsda', '123213213')
  .replace('cxvcxvcxvcx', '546546546')
  .replace('ewrewrewrew', '877876876'), // <- this is confusing as hell. And useless comma!
)

I had problems trying to understand it at first because i wasn’t thinking that the comma belongs to the .then() arguments. I thought the comma was part of the replace chain and it was a bit hard to spot the problem 😞

A workaround could be:

y.then(x => (x
  .replace('asdasdsdsda', '123213213')
  .replace('cxvcxvcxvcx', '546546546')
  .replace('ewrewrewrew', '877876876')
))

But this is ugly because the extra parens should be only added when eslint complains to the rule no-confusing-arrow. I mean, this is not a confusing arrow, so it shouldn’t need parens.

I think the comma-dangle rule should be removed from inside .then() functions, or at least have an option to relax the rule there, because this seemed like a bug at first.

[mysticatea]

@felixsanz

• Airbnb config enables comma-dangle rule with functions: 'always-multiline' option. The always-multiline option requires dangling commas if the closing parenthesis is not on the same line of the last argument. (This is not default.)
• In your first example, the closing parenthesis is not on the line of the last argument.
• So comma-dangle requires the dangling comma.

[felixsanz]

@ljharb Here it is: https://github.com/airbnb/javascript#arrows--paren-wrap

I didn’t know that (it’s hard to remember all the style guide by memory). So it’s fine now i think. Probably my fault (but it’s so confusing if you don’t know this recommendation!)

I’m gonna close this, re-open if neccesary. Thx