.eslintrc.json

{
  "extends": ["eslint:recommended", "google"],
  "parserOptions": {
    "ecmaVersion": 8,
    "sourceType": "module"
  },
  "env": {
    "browser": true,
    "es6": true
  },
  "globals": {
    "__dirname": false,
    "app": false,
    "page": false,
    "Polymer": false,
    "process": false,
    "require": false,
    "Gerrit": false,
    "Promise": false,
    "assert": false,
    "test": false,
    "flushAsynchronousOperations": false
  },
  "rules": {
    "arrow-parens": ["error", "as-needed"],
    "block-spacing": ["error", "always"],
    "brace-style": ["error", "1tbs", { "allowSingleLine": true }],
    "camelcase": "off",
    "comma-dangle": ["error", {
      "arrays": "always-multiline",
      "objects": "always-multiline",
      "imports": "always-multiline",
      "exports": "always-multiline",
      "functions": "never"
    }],
    "eol-last": "off",
    "indent": ["error", 2, {
      "MemberExpression": 2,
      "FunctionDeclaration": {"body": 1, "parameters": 2},
      "FunctionExpression": {"body": 1, "parameters": 2},
      "CallExpression": {"arguments": 2 },
      "ArrayExpression": 1,
      "ObjectExpression": 1,
      "SwitchCase": 1
    }],
    "keyword-spacing": ["error", { "after": true, "before": true }],
    "lines-between-class-members": ["error", "always"],
    "max-len": [
      "error",
      80,
      2,
      {
        "ignoreComments": true,
        "ignorePattern": "^import .*;$"
      }
    ],
    "new-cap": ["error", { "capIsNewExceptions": ["Polymer", "LegacyElementMixin", "GestureEventListeners", "LegacyDataMixin"] }],
    "no-console": "off",
    "no-multiple-empty-lines": [ "error", { "max": 1 } ],
    "no-prototype-builtins": "off",
    "no-redeclare": "off",
    "no-restricted-syntax": [
      "error",
      {
        "selector": "ExpressionStatement > CallExpression > MemberExpression[object.name='test'][property.name='only']",
        "message": "Remove test.only."
      },
      {
        "selector": "ExpressionStatement > CallExpression > MemberExpression[object.name='suite'][property.name='only']",
        "message": "Remove suite.only."
      }
    ],
    "no-undef": "off",
    "no-useless-escape": "off",
    "no-var": "error",
    "object-shorthand": ["error", "always"],
    "padding-line-between-statements": [
      "error",
      {
        "blankLine": "always",
        "prev": "class",
        "next": "*"
      },
      {
        "blankLine": "always",
        "prev": "*",
        "next": "class"
      }
    ],
    "prefer-arrow-callback": "error",
    "prefer-const": "error",
    "prefer-spread": "error",
    "quote-props": ["error", "consistent-as-needed"],
    "require-jsdoc": "off",
    "semi": [2, "always"],
    "template-curly-spacing": "error",
    "valid-jsdoc": "off",
    "require-jsdoc": 0,
    "valid-jsdoc": 0,
    "jsdoc/check-alignment": 2,
    "jsdoc/check-examples": 0,
    "jsdoc/check-indentation": 0,
    "jsdoc/check-param-names": 0,
    "jsdoc/check-syntax": 0,
    "jsdoc/check-tag-names": 0,
    "jsdoc/check-types": 0,
    "jsdoc/implements-on-classes": 2,
    "jsdoc/match-description": 0,
    "jsdoc/newline-after-description": 2,
    "jsdoc/no-types": 0,
    "jsdoc/no-undefined-types": 0,
    "jsdoc/require-description": 0,
    "jsdoc/require-description-complete-sentence": 0,
    "jsdoc/require-example": 0,
    "jsdoc/require-hyphen-before-param-description": 0,
    "jsdoc/require-jsdoc": 0,
    "jsdoc/require-param": 0,
    "jsdoc/require-param-description": 0,
    "jsdoc/require-param-name": 2,
    "jsdoc/require-param-type": 2,
    "jsdoc/require-returns": 0,
    "jsdoc/require-returns-check": 0,
    "jsdoc/require-returns-description": 0,
    "jsdoc/require-returns-type": 2,
    "jsdoc/valid-types": 2,
    "jsdoc/require-file-overview": ["error", {
      "tags": {
        "license": {
          "mustExist": true,
          "preventDuplicates": true
        }
      }
    }],
    "import/named": 2,
    "import/no-unresolved": 2,
    "import/no-self-import": 2,
    // The no-cycle rule is slow, because it doesn't cache dependencies.
    // Disable it.
    "import/no-cycle": 0,
    "import/no-useless-path-segments": 2,
    "import/no-unused-modules": 2,
    "import/no-default-export": 2
  },
  "plugins": [
    "html",
    "jsdoc",
    "import"
  ],
  "settings": {
    "html/report-bad-indent": "error"
  },
  "overrides": [
    {
      "files": ["*_html.js", "*-styles.js"],
      "rules": {
        "max-len": "off"
      }
    },
    {
      "files": ["*.html"],
      "rules": {
        "jsdoc/require-file-overview": "off"
      }
    }
  ]
}