old_contents: module.exports = {
      "env": {
          "browser": true,
          "jquery": true
      },
      "extends": "eslint:recommended",
      "rules": {
          "no-global-assign": 1,
          "indent": [
              1,
              4,
              {SwitchCase: 1}
          ],
          "linebreak-style": [
              1,
              "unix"
          ],
          "no-cond-assign": 1,
          "no-console": [1, {
              "allow": ["error", "info"]
          }],
          "no-empty": 1,
          "no-extra-semi": 1,
          "no-fallthrough": 1,
          "no-redeclare": 1,
          "no-undef": 1,
          "no-unused-vars": 1,
          "quotes": [
              1,
              "single"
          ],
          "semi": [
              1,
              "always"
          ],
          "curly": [
              1,
              "all"
          ],
          "camelcase": [
              1,
              {
                  "properties": "always"
              }
          ],
          "eqeqeq": [
              1,
              "smart"
          ],
          "one-var-declaration-per-line": [
              1,
              "always"
          ],
          "new-cap": 1
      },
      "globals": {
          "CKEDITOR": true,
          "FontFaceObserver": true,
          "ga": true,
          "gettext": true,
          "interpolate": true,
          "mdn": true,
          "Mozilla": true,
          "waffle": true,
          "Prism": true,
          "Promise": true
      }
  };
  
new_contents: module.exports = {
      'env': {
          'browser': true,
          'jquery': true
      },
      'extends': 'eslint:recommended',
      'rules': {
          'no-global-assign': 'error',
          'indent': [
              'error',
              4,
              {SwitchCase: 1}
          ],
          'linebreak-style': [
              'error',
              'unix'
          ],
          'no-cond-assign': 'error',
          'no-console': ['error', {
              'allow': ['error', 'info']
          }],
          'no-empty': 'error',
          'no-extra-semi': 'error',
          'no-fallthrough': 'error',
          'no-redeclare': 'error',
          'no-undef': 'error',
          'no-unused-vars': 'error',
          'quotes': [
              'error',
              'single'
          ],
          'semi': [
              'error',
              'always'
          ],
          'curly': [
              'error',
              'all'
          ],
          'camelcase': [
              'error',
              {
                  'properties': 'always'
              }
          ],
          'eqeqeq': [
              'error',
              'smart'
          ],
          'one-var-declaration-per-line': [
              'error',
              'always'
          ],
          'new-cap': 'error'
      },
      'globals': {
          'CKEDITOR': true,
          'FontFaceObserver': true,
          'ga': true,
          'gettext': true,
          'interpolate': true,
          'mdn': true,
          'Mozilla': true,
          'waffle': true,
          'Prism': true,
          'Promise': true
      }
  };
  
subject: Fix Bug 1401291, change warnings to error - eslint