Leading comments incorrectly include comments inside previous token

I recently contributed a rule that ended up having an issue regarding leading comments. The issue for the rule and the fix is here, but in looking at it, I started wondering if maybe this should be a fix in sourceCode.getComments rather than having to be guarded against in each individual rule.

I’m currently using ESLint v2.3.0, and the problem seems to be that comments inside a previous object literal or block get added to the following token’s leading comments array when there are no other expressions between the comment and the token. Example:

function foo() {
  var bar = {
    // comment
  };

  return bar;
}

Running sourceCode.getComments on the return expression’s node will include the comment inside the previous object literal, despite it actually being part of the previous token.

I’m assuming this is a bug - it definitely wasn’t what I was expecting to happen - can someone more knowledgable confirm?

In looking at things, it looks like maybe the change needs to happen in Espree…Happy to make a PR if this is accepted.

[kaicataldo]

@ilyavolodin Thanks! I’ll try to get a PR together in the next day or two

[kaicataldo]

PR opened for the Espree change. Will get to adding the tests on ESLint after that lands 👍

https://github.com/eslint/espree/pull/257