.eslintrc.json

{
  "env": {
    "browser": true,
    "commonjs": true,
    "es6": true,
    "node": true
  },
  "parserOptions": {
    "ecmaFeatures": {
      "jsx": false
    },
    "sourceType": "module",
    "ecmaVersion": 8
  },
  "extends": "eslint:recommended",
  "rules": {
    "no-const-assign": "warn",
    "no-this-before-super": "warn",
    "no-undef": "warn",
    "no-unreachable": "warn",
    "no-unused-vars": "warn",
    "constructor-super": "warn",
    "valid-typeof": "warn",
    "indent": ["warn", 2, { "SwitchCase": 1 }],
    "no-console": ["warn"],
    "semi": "error",
    "no-trailing-spaces": "warn",
    "quotes": ["warn", "single"],
    "eqeqeq": ["warn", "smart"],
    "no-template-curly-in-string": ["warn"],
    "curly": ["warn", "all"],
    "no-alert": "warn",
    "no-implicit-coercion": ["warn"],
    "no-implicit-globals": "error",
    "no-multi-spaces": "error",
    "no-shadow": ["warn"],
    "brace-style": "warn",
    "comma-spacing": "warn",
    "max-len": ["warn", { "code": 100 }],
    "no-var": "error",
    "prefer-const": "warn",
    "comma-dangle": ["warn", "always-multiline"]
  }
}