.eslintrc.json

{
  "env": {
    "browser": true,
    "es6": true,
    "node": true,
    "mocha": true
  },
  "extends": "eslint:recommended",
  "parser": "babel-eslint",
  "parserOptions": {
    "ecmaFeatures": {
      "experimentalObjectRestSpread": true
    },
    "sourceType": "module"
  },
  "plugins": ["mocha"],
  "rules": {
    "indent": [
      "error",
      2
    ],
    "linebreak-style": [
      "error",
      "unix"
    ],
    "quotes": [
      "error",
      "single"
    ],
    "semi": [
      "error",
      "never"
    ],
    "no-console": ["warn"],
    "comma-dangle": ["error", {
      "arrays": "only-multiline",
      "objects": "only-multiline",
      "imports": "only-multiline",
      "exports": "only-multiline",
      "functions": "never"
    }],
    "strict": [
      "error",
      "global"
    ],
    "max-len": ["error", 120],
    "curly": "warn",
    "object-curly-spacing": ["error", "always"],
    "dot-location": ["error", "property"],
    "func-call-spacing": ["error", "never"],
    "space-in-parens": ["error", "never"],
    "keyword-spacing": ["error", { "before": true }],
    "space-before-function-paren": ["error", "never"],
    "space-before-blocks": ["error", "always"],
    "space-infix-ops": ["error"],
    "mocha/handle-done-callback": ["error"],
    "mocha/no-exclusive-tests": ["error"],
    "mocha/no-global-tests": ["error"],
    "mocha/no-identical-title": ["warn"],
    "mocha/no-nested-tests": ["error"],
    "mocha/no-pending-tests": ["warn"],
    "mocha/no-sibling-hooks": ["warn"]
  }
}