no-unused-vars false positive for exported function

Tell us about your environment

• ESLint Version: 6.3.0
• Node Version: v8.11.2
• npm Version: 5.6.0

What parser (default, Babel-ESLint, etc.) are you using? @typescript-eslint/parser

Please show your full configuration:

Configuration

module.exports = {
  env: {
    browser: true,
    es6: true,
  },
  extends: [
    'eslint:recommended',
    'plugin:prettier/recommended',
  ],
  "globals": {
    "$": false
  },
  "rules": {
  }
};

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

/* exported myFunc */
/* exported myVar */
{
  var myVar = 1;

  function myFunc() {
    return 1;
  }
}

./node_modules/.bin/eslint path/to/file

What did you expect to happen?

No error for myFunc (just like for myVar)

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

69:12 error ‘myFunc’ is defined but never used no-unused-vars

Are you willing to submit a pull request to fix this bug?

[mdjermanovic]

ESLint’s scope manager treats function declarations as block-scoped in ES2015+, even in non-strict mode. Therefore, the rule doesn’t see myFunc as being exported.

It doesn’t work like that in browsers because they are required to support legacy code. The example from the original post would indeed create global myFunc (in non-strict mode only).

But, it’s a legacy feature that should be avoided in new code, e.g. by using var myFunc = function () {} or window.myFunc = function () {}

[eslint-deprecated[bot]]

Unfortunately, it looks like there wasn’t enough interest from the team or community to implement this change. While we wish we’d be able to accommodate everyone’s requests, we do need to prioritize. We’ve found that issues failing to reach accepted status after 21 days tend to never be accepted, and as such, we close those issues. This doesn’t mean the idea isn’t interesting or useful, just that it’s not something the team can commit to.

Thanks for contributing to ESLint and we appreciate your understanding.