.eslintrc.json

{
    "extends": "airbnb",
    "rules": {
      "space-in-parens": ["error", "always", { "exceptions": ["{}"] }],
      "comma-style": ["error", "first", { "exceptions": { "ArrayExpression": true, "ObjectExpression": true } }],
      "comma-dangle": ["error", "only-multiline"],
      "space-before-function-paren": ["error", "never"],
      "func-names": 0,
      "no-param-reassign": 0,
      "one-var-declaration-per-line": ["error", "initializations"],
      "no-underscore-dangle": 0,

      // es6
      "object-shorthand": 0,
      "one-var": ["error", "always"],
      "no-var": 0,
      "prefer-template": 0,
      "prefer-arrow-callback": 0,
      "prefer-rest-params": 0
    },
    "env": {
      "mocha": true
    },
    "globals": {
      "expect": true
    }
}