Request for New "curly" Option: "multi-or-nest-and-exit"

The current options for the “curly” rule are great, but it would be really nice if it was possible to express an added constraint: in order for a one-line statement to be allowed, it has to exit somehow (ie. return or break or continue). In other words, this proposed “multi-or-nest-and-exit” option would be identical to “multi-or-nest”, except that:

if (foo) bar += 1;

would be invalid. Only:

if (foo) return bar + 1;

or:

if (foo) {
    bar += 1;
}

would be allowed. The reason for this distinction comes from the purpose of the rule itself. “curly” exists because it’s very easy to misunderstand code like:

if (foo) bar += 1;
baz += 1;

It’s easy to read that code and (especially if the indentation is wrong) think that baz += 1 will only trigger if (foo). However, by limiting such one-line conditionals to exit statements, you eliminate that confusion. It’s much harder for one to misunderstand:

if (foo) return bar + 1;
baz += 1;

because the reader knows that any code after a return won’t be run.

While I’m not sure how popular this rule is, it’s used at my company and I’ve seen it used at at least one other company, so I suspect that others might appreciate this rule option also.

Thanks for your consideration.

P.S. While I don’t have a pull request ready or anything (TBH I’ve never even looked at the ESLint source), if the ESLint maintainers want to add this option I would be more than happy to either create the pull request myself or use a “bounty” to help get this implemented by someone who is more familiar with ESLint’s source code.

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[BYK]

I find this a bit too specific to be part of the core.

[ilyavolodin]

I agree. This is more of a personal preference. It’s a good case for a plugin though. @machineghost if you run into problems creating this, stop by our gitter channel and we’ll try to help. Also, if you do end up creating this, please post a link here in case somebody wants to use the same style.