.eslintrc.json

{
  "extends": ["eslint:recommended"],
  "plugins": ["node"],
  "root": true,
  "ignorePatterns": [
    "chat/app",
    "public",
    "*.html",
    "*.scss",
    "*.css",
    "*.json",
    "*.spec.js"
  ],
  "parserOptions": {
    "sourceType": "module",
    "ecmaVersion": 2020
  },
  // root env (node scripts, including webpack)
  "env": {
    "es6": true,
    "browser": false,
    "node": true,
    "commonjs": true,
    "jquery": false
  },
  // rules for syntax errors
  "rules": {
    "no-var": "error",
    "prefer-const": [
      "error",
      { "destructuring": "any", "ignoreReadBeforeAssign": false }
    ],
    "no-multi-assign": "error",
    "one-var": ["error", "never"],
    "quotes": [
      "error",
      "single",
      { "avoidEscape": true, "allowTemplateLiterals": true }
    ],
    // console is OK for node/webpack so far
    "no-console": "off"
  }
}