eslint-configured globals should not be reported as unused

• ESLint Version: v3.11.1
• Node Version: v6.9.1
• npm Version: 4.0.5

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

Please show your full configuration:

See cat .eslintrc.json, below

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

kieffer@Roberts-MacBook-Pro$ cat .eslintrc.json
{
  "rules": {
    "no-unused-vars": "warn",
    "no-undef": "error"
  }
}

kieffer@Roberts-MacBook-Pro$ cat foo.js
/* global foo */

kieffer@Roberts-MacBook-Pro$ eslint foo.js

/Users/kieffer/work/foo.js
  1:11  warning  'foo' is defined but never used  no-unused-vars

✖ 1 problem (0 errors, 1 warning)

What did you expect to happen?

Since foo is never actually declared in real code, it should not be reported as being unused.

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

The comment-configured global foo is reported as unused, despite not being defined anywhere in real code.

“Just remove the unused var(s) from the configuration comment, you moron!”

The use-case for this is that I have code that dynamically creates helper methods for each of our DB models. Something along the lines of …

// Dynamically create some helper functions based on DB model classes
for (var modelName in models) global['is' + modelName] = function(thing) {...}

// Tell eslint about the functions we just created
/* global isUser, isAccount, isSession, etc... */

This configuration comment avoids the more serious no-undef errors if/when a helper function is used. But I end up with no-unused-vars warnings for the ones that aren’t. It’s a lose-lose situation, as far as getting eslint to shut up goes. 😕

Make sense?

[not-an-aardvark]

If the globals are available for all files rather than a particular file, it might be better to specify them in your config:

globals:
  window: true
  document: true
  isUser: true
  # ...

[broofa]

@not-an-aardvark TIL And feel like a bit of an idiot. Thanks for correcting me. 'Not sure why I thought global was scoped to a module.

I need to ponder the implications of that for my own code. It may be I should be doing this another way.

I do think there’s still an issue here. The eslint docs imply inline global and config file globals should be interchangeable:

You can define global variables either using comments inside of a file or in the configuration file.

(link). That they’re not is (to me) a little weird. But given my own misunderstanding of what my code is doing I’ll concede this isn’t worth attending to for the time being. Sorry to have troubled you folks.