.eslintrc.json

{
    "parser": "@babel/eslint-parser",
    "parserOptions": {
        "ecmaVersion": 2016,
        "ecmaFeatures": {
            "jsx": true
        },
        "requireConfigFile": false,
        "sourceType": "module"
    },
    "extends": [
        "plugin:@wordpress/eslint-plugin/custom",
        "plugin:@wordpress/eslint-plugin/esnext",
        "plugin:@wordpress/eslint-plugin/es5",
        "plugin:@wordpress/eslint-plugin/jsx-a11y",
        "plugin:@wordpress/eslint-plugin/react",
        "plugin:@wordpress/eslint-plugin/i18n",
        "plugin:@wordpress/eslint-plugin/test-e2e",
        "plugin:@wordpress/eslint-plugin/test-unit"
    ],
    "rules": {
        "no-unused-vars": [
            "error",
            {
                "vars": "all",
                "args": "after-used",
                "ignoreRestSiblings": false
            }
        ],
        "no-undef": [
          "error"
        ]
    },
    "overrides": [
        {
            "excludedFiles": "*.min.js",
            "files": [
                "**/test/*.js"
            ],
            "env": {
                "jest": true
            }
        }
    ]
}