.eslintrc.json

{
  "extends": "eslint:recommended",
  "parserOptions": {
    "ecmaVersion": 2017,
    "sourceType": "script",
    "ecmaFeatures": {
      "jsx": false
    }
  },
  "env": {
    "node": true,
    "browser": false,
    "es6": true
  },
  "rules": {
    "array-callback-return": "error",
    "no-empty": [
      "error",
      {
        "allowEmptyCatch": true
      }
    ],
    "no-lonely-if": "error",
    "no-var": "error",
    "object-shorthand": "error",
    "prefer-arrow-callback": [
      "error",
      {
        "allowNamedFunctions": true
      }
    ],
    "prefer-const": [
      "error",
      {
        "ignoreReadBeforeAssign": true
      }
    ],
    "prefer-destructuring": [
      "error",
      {
        "object": true,
        "array": false
      }
    ],
    "prefer-spread": "error",
    "prefer-template": "error",
    "radix": "error",
    "strict": "error",
    "quotes": [
      "error",
      "single"
    ]
  },
  "overrides": [
    {
      "files": ["test/**/*"],
      "env" : {
        "mocha": true
      }, // Or *.test.js
      "rules": {
        "require-jsdoc": "off",
        "no-undef" : "off",
        "no-unused-vars" : "off",
        "strict": "off"
      }
    }
  ]
}