.eslintrc.json

{
  "extends": "eslint:recommended",
  "env": {
    "browser": true,
    "node": true,
    "es6": true
  },
  "plugins": [
    "html"
  ],
  "globals": {
    "Polymer": false,
    "Vaadin": false
  },
  "parserOptions": {
    "sourceType": "module"
  },
  "rules": {
    "curly": 2,
    "no-caller": 2,
    "no-extend-native": 2,
    "no-extra-bind": 2,
    "no-invalid-this": 2,
    "no-multi-spaces": 2,
    "no-new-wrappers": 2,
    "no-with": 2,
    "array-bracket-spacing": [2, "never"],
    "brace-style": 2,

    "camelcase": [2, {"properties": "never"}],
    "comma-spacing": 2,
    "comma-style": 2,
    "computed-property-spacing": 2,
    "func-call-spacing": 2,
    "indent": [2, 2, {"SwitchCase": 1}],
    "key-spacing": 2,
    "keyword-spacing": 2,
    "linebreak-style": 2,
    "max-len": [2, {"code": 140}],
    "no-array-constructor": 2,
    "no-multiple-empty-lines": [2, {"max": 2}],
    "no-new-object": 2,
    "no-trailing-spaces": 2,
    "object-curly-spacing": 2,
    "quote-props": [2, "consistent"],
    "quotes": [2, "single", {"allowTemplateLiterals": true}],
    "semi-spacing": 2,
    "semi": 2,
    "space-before-blocks": 2,
    "space-before-function-paren": [2, "never"],
    "space-in-parens": 2,
    "space-infix-ops": 2,
    "spaced-comment": [2, "always"],

    "arrow-spacing": 2,
    "constructor-super": 2,
    "no-confusing-arrow": 2,
    "no-const-assign": 2,
    "no-dupe-class-members": 2,
    "no-duplicate-imports": 2,
    "no-this-before-super": 2,
    "no-useless-computed-key": 2,
    "no-useless-constructor": 2,
    "no-useless-rename": 2,
    "prefer-const": 2,
    "rest-spread-spacing": 2,
    "template-curly-spacing": 2,

    "no-unused-vars": ["error", { "args": "none" }]
  },
  "overrides": [{
    "files": ["gulpfile.js"],
    "parserOptions": {
      "ecmaVersion": 2017
    }
  }]
}