.eslintrc.json

{
  "extends": [
    "eslint:recommended",
    "plugin:node/recommended",
    "plugin:prettier/recommended"
  ],
  "parserOptions": {
    "ecmaVersion": 2020,
    "sourceType": "module"
  },
  "plugins": [
    "node"
  ],
  "rules": {
    "indent": [
      "error",
      2
    ],
    "linebreak-style": [
      "error",
      "unix"
    ],
    "quotes": [
      "error",
      "single"
    ],

    "no-undef": "off",

    // Best practice
    "eqeqeq": "warn",
    "curly": "error",
    "dot-location": ["error", "property"],
    "dot-notation": "error",
    "no-alert": "error",
    "object-shorthand": ["error", "always"],
    "no-console": ["error", { "allow": ["warn", "error"] }],

    // Style
    "array-bracket-spacing": "error",
    "object-curly-spacing": "off",
    "brace-style": "error",
    "comma-dangle": ["error", "only-multiline"],
    "comma-spacing": "error",
    "comma-style": "error",
    "eol-last": "error",
    "key-spacing": "error",
    "keyword-spacing": "error",
    "no-lonely-if": "error",
    "no-multiple-empty-lines": "error",
    "no-tabs": "error",
    "semi-style": ["error", "last"],
    "spaced-comment": ["error", "always"],

    // ES 6
    "arrow-spacing": "error",
    "no-var": "error"
  }
}