@kiwi/eslint-config/rules/variables.js

A neat and opinionated eslint config

const confusingBrowserGlobals = require('confusing-browser-globals');

module.exports = {
  rules: {
    // Disallow labels that share a name with a variable
    // https://eslint.org/docs/rules/no-label-var
    'no-label-var': 'error',

    // Disallow specific globals
    // https://eslint.org/docs/rules/no-restricted-globals
    'no-restricted-globals': ['error', 'isFinite', 'isNaN'].concat(
      confusingBrowserGlobals,
    ),

    // Disallow declaration of variables already declared in the outer scope
    // https://eslint.org/docs/rules/no-shadow
    'no-shadow': [
      'error',
      {
        allow: [
          'cb',
          'callback',
          'data',
          'done',
          'error',
          'item',
          'items',
          'next',
          'reject',
          'res',
          'resolve',
          'response',
        ],
      },
    ],

    // Disallow shadowing of names such as arguments
    // https://eslint.org/docs/rules/no-shadow-restricted-names
    'no-shadow-restricted-names': 'error',

    // Disallow use of undefined when initializing variables
    // https://eslint.org/docs/rules/no-undef-init
    'no-undef-init': 'error',

    // Disallow declaration of variables that are not used in the code
    // https://eslint.org/docs/rules/no-unused-vars
    'no-unused-vars': [
      'error',
      {
        ignoreRestSiblings: true,
        argsIgnorePattern: '_+',
      },
    ],

    // Disallow use of variables before they are defined
    // https://eslint.org/docs/rules/no-use-before-define
    'no-use-before-define': [
      'off',
      {
        functions: false,
        classes: false,
        variables: true,
      },
    ],
  },
};