ESLint 6.2.2 + babel-eslint 10.0.3 + no-unused-vars false positive with for-of loop

Tell us about your environment

• ESLint Version: 6.2.2
• Node Version: 12.6.0
• npm Version: 6.11.2

What parser (default, Babel-ESLint, etc.) are you using? Babel-ESLint 10.0.3

Also tried Babel-ESLint 10.0.2 but ran into https://github.com/eslint/eslint/issues/12117. Following the advice there, I tried running 10.0.3

Please show your full configuration:

Configuration

{
  parser: 'babel-eslint',
  parserOptions: {
    ecmaVersion: 6,
    sourceType: 'module',
    ecmaFeatures: {
      jsx: true,
      generators: true,
      experimentalObjectRestSpread: true
    }
  },
  extends: ["airbnb"],
  rules: {
    'react/sort-comp': 0,
    "react/require-default-props": 0,
    "react/forbid-prop-types": ['error', { forbid: ['any', 'array']}],
    "react/destructuring-assignment": 0,
    "react/static-property-placement": ['error', 'static public field'],
    "react/state-in-constructor": 0,
    "react/jsx-props-no-spreading": 0,

    "linebreak-style": 0,
    "function-paren-newline": ['error', 'consistent'],
    "object-curly-newline": ['error', { 'consistent': true }],

    "babel/semi": 2,
    "no-param-reassign": ['error', { props: false }],
    "arrow-parens": ['error', 'as-needed', { "requireForBlockBody": true }],
  }
}

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

for (const type of TYPES) {
  const itemsOfType = items.filter(item => item.__typename === type);
}

      for (const [name, offset] of items) {
        if (offset >= scrollTop) {
          this.setState({ active: name });
          return;
        }
      }

npm run lint

What did you expect to happen? Get no errors

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

  98:10  error  'type' is defined but never used             no-unused-vars
  126:15  error  'name' is defined but never used          no-unused-vars
  126:21  error  'offset' is defined but never used          no-unused-vars

Are you willing to submit a pull request to fix this bug? Yes, but I can’t commit to it in the next couple of weeks

[platinumazure]

@camyyssa It looks like your babel-eslint is still using the old eslint-scope for some reason. Try blowing away the node_modules and rerunning npm install, does that resolve your issue?

[camyyssa]

😳 It does!

I could have found the steps to resolve this on my own 😊. Sorry to waste your time @platinumazure 🙂 but thank you so much for the help!

For future me, and in case you stumble on this post because you have the same problem:

1. Upgrade dependency, remove node-modules, and try again
2. If you’re using the library as a sub-dependency, try to fix it to the latest version using yarn resolutions https://yarnpkg.com/lang/en/docs/selective-version-resolutions/ (doesn’t seem to exist on npm)

This is a temporary solution, to check if updating the dependency solves the problem. It looks dangerous to me to keep this in your package.json long-term, since it forces the package manager to install a certain version of a sub-dependency