Fix: no-else-return false positive for ifs in single-statement position

[not-an-aardvark]

What is the purpose of this pull request? (put an "X" next to item)

[x] Bug fix

Tell us about your environment

• ESLint Version: master
• Node Version: 7.7.4
• npm Version: 4.1.2

What parser (default, Babel-ESLint, etc.) are you using?

default

Please show your full configuration:

rules:
  no-else-return: error

What did you do? Please include the actual source code causing the issue.

while (foo)
  if (bar)
    return;
  else
    baz();

What did you expect to happen?

I expected no error to be reported.

What actually happened? Please include the actual, raw output from ESLint.

The rule reported an error and recommended fixing the code to

while (foo)
  if (bar)
    return;
  baz();

However, this code doesn't work the same way, because baz() is no longer in the while loop.

What changes did you make? (Give an overview)

Fixing errors from no-else-return requires splitting a single statement into two statements. This means that there is no reasonable fix for the errors when the if statement is in a position where only a single statement is allowed, so the rule should not report this case.

Is there anything you'd like reviewers to focus on?

Nothing in particular

[mention-bot]

@not-an-aardvark, thanks for your PR! By analyzing the history of the files in this pull request, we identified @vitorbal, @xdumaine and @iancmyers to be potential reviewers.

[eslintbot]

LGTM

[xdumaine]

Looks good to me. Good catch.