title: eslint errors on .js files
body: <p>My codebase is full of <code>.js</code> files and I am running <code>eslint</code> on a particular file.
  I get below errors:</p>
  
  <pre><code> 1:8   error  'React' is defined but never used
                                no-unused-vars
  1:27  error  Trailing spaces not allowed
                                no-trailing-spaces
  2:1   error  'prop-types' should be listed in the project's dependencies. Run
  'npm i -S prop-types' to add it  import/no-extraneous-dependencies
  7:13  error  Arrow function used ambiguously with a conditional expression
                                no-confusing-arrow
  11:3   error  Prop type `array` is forbidden
                                react/forbid-prop-types
  </code></pre>
  
  <p>My <code>.eslintrc.js</code></p>
  
  <pre><code>module.exports = {
    env: {
      browser: true,
      commonjs: true,
      es6: true,
    },
    extends: [
      'airbnb',
      "plugin:react/recommended"
    ],
    globals: {
      Atomics: 'readonly',
      SharedArrayBuffer: 'readonly',
    },
    parserOptions: {
      ecmaFeatures: {
        jsx: true,
      },
      ecmaVersion: 2018,
    },
    plugins: [
      'react'
    ],
    rules: {
      "react/jsx-uses-react": 1,
    },
  };
  </code></pre>
  
  <p>My <code>Package.json</code></p>
  
  <pre><code>"devDependencies": {
      "@commitlint/cli": "^8.1.0",
      "@commitlint/config-conventional": "^8.1.0",
      "babel-cli": "6.18.0",
      "babel-plugin-dynamic-import-node": "1.0.0",
      "babel-plugin-react-intl": "2.2.0",
      "babel-plugin-react-transform": "2.0.2",
      "babel-plugin-transform-es2015-modules-commonjs": "6.18.0",
      "babel-plugin-transform-react-constant-elements": "6.9.1",
      "babel-plugin-transform-react-inline-elements": "6.8.0",
      "babel-plugin-transform-react-remove-prop-types": "0.2.11",
      "babel-preset-latest": "6.16.0",
      "babel-preset-react-hmre": "1.1.1",
      "circular-dependency-plugin": "2.0.0",
      "coveralls": "2.11.15",
      "css-loader": "^0.23.1",
      "enzyme": "^2.7.0",
      "eslint": "3.11.1",
      "eslint-config-airbnb": "13.0.0",
      "eslint-config-airbnb-base": "10.0.1",
      "eslint-import-resolver-webpack": "0.8.0",
      "eslint-plugin-import": "2.2.0",
      "eslint-plugin-jsx-a11y": "2.2.3",
      "eslint-plugin-react": "6.7.1",
      "eslint-plugin-redux-saga": "0.1.5",
      "eventsource-polyfill": "0.9.6",
      "exports-loader": "0.6.3",
      "file-loader": "^0.9.0",
      "html-loader": "0.4.4",
      "html-webpack-plugin": "2.24.1",
      "husky": "^3.0.5",
      "lint-staged": "^3.2.1",
      "ngrok": "2.2.4",
      "npm-run-all": "^4.1.5",
      "prettier": "^1.18.2",
      "standard-version": "^7.0.0",
      "webpack-dev-middleware": "^1.11.0",
      "webpack-hot-middleware": "^2.18.0"
  }
  </code></pre>
  
  <p>I tried with various solutions below:</p>
  
  <pre><code>/*eslint-disable no-unused-vars*/
  var React = require('react');
  /*eslint-enable no-unused-vars*/
  </code></pre>
  
  <p>And:</p>
  
  <pre><code>var React = require('react');    // eslint-disable-line no-unused-vars
  </code></pre>
  
  <p>but can't do it for almost 300-500 files.</p>
  
  <p>expectations is to resolve all the errors thrown in <code>.js</code> files.</p>
  
  <p>Thanks in advance.</p>