.eslintrc.json

{
  "parser": "babel-eslint",
  "parserOptions": {
    "ecmaVersion": 7,
    "sourceType": "module",
    "ecmaFeatures": {
      "jsx": true,
      "spread": true,
      "objectLiteralShorthandMethods": true,
      "experimentalObjectRestSpread": true
    }
  },
  "extends": [
    "eslint:recommended",
    "plugin:react/recommended",
    "plugin:import/errors",
    "plugin:import/warnings"
  ],
  "rules": {
    "no-console": ["error", {
      "allow": ["warn", "error"] 
    }],
    "no-unused-vars": ["error", {
      "varsIgnorePattern": "_", 
      "ignoreRestSiblings": true,
      "args": "none"
    }],
    "semi": ["error", "never"],
    "import/no-extraneous-dependencies": ["error"]
  },
  "env": {
    "browser": true,
    "es6": true,
    "amd": true,
    "webextensions": true
  },
  "overrides": [
    {
      "files": "test/**/*.test.js",
      "env": {
        "jest": true
      }
    }
  ]
}