Fairwords ESLint rules

Installation

# Install this package:
npm i -D eslint @honcho/eslint-plugin

# If you want to lint your JSDocs, install this:
npm i -D eslint-plugin-jsdoc

# If you're using TS, install and configure this package:
npm i -D @typescript-eslint/parser @typescript-eslint/eslint-plugin

# Another recommended linting rules package:
npm i -D eslint-plugin-sonarjs

Usage

This package has several (rather strict) preconfigured ESLint rule sets you can use in your JS / TS project:

• plugin:@honcho/js All JS rules. Doesn't include recommended.
  • plugin:@honcho/js-base base JS ESLint rules.
  • plugin:@honcho/js-best-practices ESLint best practices.
  • plugin:@honcho/js-complexity Complexity related rules.
  • plugin:@honcho/js-ecma6 ECMA6 features related rules.
  • plugin:@honcho/js-only JS-only rules. These rules seem to cause problem, if you're not using them on JS files only.
  • plugin:@honcho/js-prettier We had Prettier and ESLint rules fighting with each other, so I moved most of the Prettier configs here to this section.
  • plugin:@honcho/js-spacing Rules that regulates spaces in code
• plugin:@honcho/js-best-practices JSDoc rules. Doesn't turn recommended JSDoc rules on, you should turn them on separately. If you're using it, you must install and set up JSDoc eslint plugin package (we use 36.0.7 version).
• plugin:@honcho/ts TypeScript rules. Doesn't turn recommended TS rules on, you should turn them on separately. If you're using any rule from this section, you must install and set up TS ESLint plugin package (we use 4.28.4 version). Configs that has typed in their name require type-checking and will build your code to run the checks. You will need to set up your project to utilize these advanced rules.
  • plugin:@honcho/ts-extensions Vanilla ESLint extension rules. Quote from docs: "In some cases, ESLint provides a rule itself, but it doesn't support TypeScript syntax; either it crashes, or it ignores the syntax, or it falsely reports against it. In these cases, we create what we call an extension rule; a rule within our plugin that has the same functionality, but also supports TypeScript". These rules turn the vanilla ESLint rules off and use its "patched" version.
    • plugin:@honcho/ts-extensions-untyped Extension rules that doesn't require type-checking.
    • plugin:@honcho/ts-extensions-typed Extension rules that require type-checking and will build your code to run the checks.
  • plugin:@honcho/ts-additions Additional rules that were not present in vanilla ESLint.
    • plugin:@honcho/ts-additions-untyped Additional rules that doesn't require type-checking.
    • plugin:@honcho/ts-additions-typed Additional rules that require type-checking.
    • plugin:@honcho/ts-additions-typed-strict Additional rules that require type-checking and strictNullChecks (or strict) option set.

We also recommend using SonarJS ESLint plugin.

Example:

You can use this example .eslintrc.js config as a starting point for your new project:

// .eslintrc.js
const ecmaVersion = 2020;

module.exports = {
  'plugins': [],
  'env': {
    'browser': true,
    'es6': true,
    'node': true,
    'jest': true,
  },
  'parserOptions': {
    ecmaVersion,
    'sourceType': 'module',
    'ecmaFeatures': {},
  },
  'overrides': [
    {
      'files': ['*.ts', '*.js'],
      'extends': [
        'eslint:recommended',
        'plugin:jsdoc/recommended',
        'plugin:sonarjs/recommended',
        'plugin:@honcho/js',
        'plugin:@honcho/jsdoc',
      ],
      'plugins': [
        'sonarjs',
        '@honcho',
        'jsdoc',
      ],
      'rules': {
        // Disallow declarations in the global scope, crashes linter for non-JS or non-TS files
        'no-implicit-globals': 'error',
      },
    },
    {
      'files': ['*.js'],
      'extends': ['plugin:@honcho/js-only'],
      'plugins': ['@honcho'],
      'rules': {},
    },
    {
      'files': ['*.ts'],
      'plugins': [
        '@typescript-eslint',
        '@honcho',
      ],
      'extends': [
        'plugin:@typescript-eslint/recommended',
        'plugin:@honcho/ts-extensions',
        'plugin:@honcho/ts-additions-untyped',
        'plugin:@honcho/ts-additions-typed',
        'plugin:@typescript-eslint/recommended-requiring-type-checking',
      ],

      'parser': '@typescript-eslint/parser',
      'parserOptions': {
        'tsconfigRootDir': __dirname,
        'project': ['./tsconfig.base.json'],
      },
      'rules': {},
    },
    {
      'files': ['*.test.js', '*.test.ts'],
      'rules': {
        // Jest is built on callbacks, so we have to increase the counts here
        'max-nested-callbacks': ['error', 5],
        
        'max-lines-per-function': 'off',
        
        // It's somewhat ok to use magic numbers in tests
        '@typescript-eslint/no-magic-numbers': 'off',
        
        // SonarJS doesn't like it when you use the same names for tests a lot of times
        'sonarjs/no-duplicate-string': 'off',
      },
    },
  ],

  /*
   * https://github.com/angular-eslint/angular-eslint#seriously-move-mostly-all-configuration-into-overrides
   * > Even though you may be more familiar with including ESLint rules, plugins etc at the top level of your config
   * object, we strongly recommend only really having overrides (and a couple of other things like ignorePatterns, root
   * etc) at the top level and including all plugins, rules etc within the relevant block in the overrides array.
   */
  'extends': [],
  'rules': {},
};