.eslintrc.json

{
  "extends": "eslint:recommended",
  "parser": "babel-eslint",
  "parserOptions": {
    "ecmaVersion": 6,
    "sourceType": "module"
  },
  "rules": {
    "no-console": "off",
    "no-var": "error",
    "semi": "error",
    "strict": "error",
    "valid-jsdoc": ["error", {
      "requireReturn": false,
      "prefer": {
        "arg": "param",
        "argument": "param",
        "returns": "return"
      },
      "preferType": {
        "Boolean": "boolean",
        "Number": "number",
        "String": "string",
        "object": "Object",
        "array": "Array"
      }
    }],
    "no-useless-escape": "off"
  },
  "env": {
    "browser": true,
    "es6": true
  },
  "plugins": [
    "html"
  ],
  "globals": {
    "customElements": true,
    "HTMLImports": true,
    "Polymer": true,
    "ShadyDOM": true,
    "ShadyCSS": true,
    "JSCompiler_renameProperty": true
  }
}