.eslintrc.json

{
  "plugins": [
    "jest",
    "react"
  ],
  "parser": "babel-eslint",
  "env": {
    "jest/globals": true,
    "browser": true,
    "es6": true,
    "node": true
  },
  "parserOptions": {
    "ecmaVersion": 7,
    "ecmaFeatures": {
      "jsx": true
    }
  },
  "rules": {
    "global-require": 0,
    "comma-spacing": [
      "warn",
      {
        "before": false,
        "after": true
      }
    ],
    "implicit-arrow-linebreak": [
      "warn",
      "beside"
    ],
    "eqeqeq": [
      "warn",
      "smart"
    ],
    "func-style": [
      "error",
      "expression"
    ],
    "indent": [
      "warn",
      2
    ],
    "linebreak-style": [
      "error",
      "unix"
    ],
    "no-multiple-empty-lines": [
      "error",
      {
        "max": 2,
        "maxEOF": 1
      }
    ],
    "quotes": [
      "error",
      "single"
    ],
    "semi": [
      "error",
      "always"
    ],
    "no-var": "error",
    "prefer-arrow-callback": "error"
   }
}