Require block comments to be balanced

[feross]

http://eslint.org/docs/rules/spaced-comment

This rule (which is already enabled in standard) has a new option to enforce "balanced" spacing in block comments.

For example, this would be an error:

/* This is a block comment*/

It would be need to be rewritten like this:

/* This is a block comment */

As part of this change, I propose that we remove the exceptions that allow the keywords "global", "global", "eslint", and "eslint-disable" to be used without a space:

/*global myVar */

It's odd to enforce a space at the end while making it optional at the beginning for these keywords. With these exceptions removed, this is how these comments would need to be written:

/* global myVar */

Eslint handles space or no-space versions of these directives without issue.

The number of affected repos is moderate (2%):

1..422
# tests 422
# pass  412
# fail  10

Thoughts?

[dcousens]

LGTM

[feross]

This will be included in standard v8

[Jessidhia]

I kinda like being able to write eslint directives in a "style-violating" way (and wish I could do it with more of them, like //eslint-disable-line) because, if the directive has a typo, it will be flagged by the linter instead of just being ignored. OTOH, if you have a directive, it's because it's disabling or configuring specific rules, and if the directive was being ignored, you'd be getting warnings for the things it tries to fix...

[feross]

@Kovensky Interesting point. Your last point is correct. If the rule isn't getting picked up (due to a typo) then you'll get a warning because the rule you were trying to disable wasn't actually disabled.

I think this rule change is a good move since there were 2 ways to do something, and now there will be only one.