eslintrc の設定を見直す

$ sudo npm install -g eslint eslint-plugin-react
$ eslint --version
v5.1.0

.eslintrc

{
  "plugins": ["react"],
  "extends": [
    "eslint:recommended",
    "plugin:react/recommended"
  ],
  "env": {
    "browser"  : true,
    "node"     : true,
    "mocha": true,
    "es6"      : true
  },
  "rules": {
    "react/prop-types": "off",
    "eqeqeq": ["error", "smart"],
    "no-console": "off",
    "semi": ["warn", "always"],
    "vars-on-top": "warn"
  },
  "parserOptions": {
    "ecmaVersion": 2018,
    "sourceType": "module",
    "ecmaFeatures": {
      "jsx": true
    }
  }
}