.eslintrc.json

{
  "extends": "airbnb-base",
  "env": {
    "browser": true,
    "mocha": true
  },
  "parser": "@babel/eslint-parser",
  "parserOptions": {
    "requireConfigFile": false,
    "sourceType": "module"
  },
  "rules": {
    "brace-style": "warn",
    "class-methods-use-this": 0,
    "comma-dangle": [
      "warn",
      "only-multiline"
    ],
    "indent": [
      "warn",
      2,
      {
        "SwitchCase": 1
      }
    ],
    "lines-between-class-members": "off",
    "linebreak-style": "off",
    "max-len": [
      "warn",
      128
    ],
    "no-promise-executor-return": "warn",
    "no-var": "error",
    "no-useless-constructor": "off",
    "object-curly-newline": "warn",
    "object-curly-spacing": "warn",
    "prefer-arrow-callback": "off",
    "prefer-const": "warn",
    "prefer-destructuring": "off",
    "import/extensions": [
      "error",
      "ignorePackages",
      {
        "js": "always"
      }
   ]
  }
}