.eslintrc.js

module.exports = {
    "plugins": [
        "jest"
    ],
    "env": {
        "node": true,
        "browser": true,
        "es6": true,
        "jest": true,
        "jest/globals": true
    },
    "globals": {
        "_": "readonly"
    },
    "extends": [
        "eslint:recommended",
        "plugin:jest/recommended"
    ],
    "parserOptions": {
        "allowImportExportEverywhere": true,
        "ecmaVersion": 2017,
        "ecmaFeatures": {
            "impliedStrict": true
        }
    },
    "rules": {
        "no-bitwise": "error",
        "curly": "error",
        "eqeqeq": "error",
        "guard-for-in": "error",
        "no-extend-native": "error",
        "no-inner-declarations": "off",
        "no-use-before-define": ["error", "nofunc"],
        "no-caller": "error",
        "no-sequences": "error",
        "no-irregular-whitespace": "error",
        "no-new": "error",
        "no-shadow": "error",
        "no-undef": "error",
        "no-unused-vars": [
            "error",
            {
                "vars": "all",
                "args": "none"
            }
        ],
        "no-console": "off",
        "no-trailing-spaces": "error",
        "space-before-function-paren": [
            "error",
            {
                "anonymous": "always",
                "asyncArrow": "always",
                "named": "never",
            }
        ],
        "array-bracket-spacing": "error",
        "space-in-parens": "error",
        "space-before-blocks": "error",
        "comma-dangle": "error",
        "eol-last": "error",
        "new-cap": [
            "error",
            {
                "capIsNew": false,
                "properties": false
            }
        ],
        "dot-notation": "error",
        "indent": ["error", 4]
    },
    "overrides": [
        {
            "files": [
                "**/*.test.js"
            ],
            "env": {
                "jest": true
            }
        }
    ]
};