eslint-config-pyosh

pyo-sh's ESLint shareable config for TypeScript projects.

Referenced by eslint-config-airbnb (not based on).

⚠️ Version 4.0 Breaking Changes

Version 4.0 introduces breaking changes to support ESLint 9 and @typescript-eslint v8:

• Requires ESLint 9.x (Flat Config format)
• Requires @typescript-eslint v8.x
• Removed .eslintrc format support
• See Migration Guide below

If you need the old .eslintrc format, use version 3.x:

npm install --save-dev eslint-config-pyosh@3

Requirements

• Node.js: 18.x or higher
• ESLint: 9.x
• TypeScript: 5.x (if using TypeScript configs)

Installation

Install the package and its peer dependencies:

npm install --save-dev eslint-config-pyosh \
  @eslint/js \
  @typescript-eslint/eslint-plugin \
  @typescript-eslint/parser \
  eslint \
  eslint-config-prettier \
  eslint-import-resolver-typescript \
  eslint-plugin-import \
  eslint-plugin-prettier \
  globals \
  prettier

Or check peer dependencies:

npm info "eslint-config-pyosh@latest" peerDependencies

Usage

Basic JavaScript Config

For JavaScript projects with import rules:

eslint.config.js:

const pyoshConfig = require('eslint-config-pyosh');

module.exports = [
  ...pyoshConfig,
];

TypeScript Config

For TypeScript projects:

eslint.config.js:

const pyoshConfig = require('eslint-config-pyosh');
const pyoshTsConfig = require('eslint-config-pyosh/typescript');

module.exports = [
  ...pyoshConfig,
  ...pyoshTsConfig,
];

Note: Make sure you have a tsconfig.json in your project root.

With Prettier

For projects using Prettier:

eslint.config.js:

const pyoshConfig = require('eslint-config-pyosh');
const pyoshTsConfig = require('eslint-config-pyosh/typescript');
const pyoshPrettierConfig = require('eslint-config-pyosh/prettier');

module.exports = [
  ...pyoshConfig,
  ...pyoshTsConfig,
  ...pyoshPrettierConfig,
];

Full Example

Complete configuration with custom settings:

eslint.config.js:

const js = require('@eslint/js');
const globals = require('globals');
const pyoshConfig = require('eslint-config-pyosh');
const pyoshTsConfig = require('eslint-config-pyosh/typescript');
const pyoshPrettierConfig = require('eslint-config-pyosh/prettier');

module.exports = [
  // Add ESLint recommended rules
  js.configs.recommended,

  // Add pyosh configs
  ...pyoshConfig,
  ...pyoshTsConfig,
  ...pyoshPrettierConfig,

  // Custom overrides
  {
    languageOptions: {
      globals: {
        ...globals.browser,
        ...globals.node,
        ...globals.es2021,
      },
    },
    ignores: ['dist/**', 'build/**', 'node_modules/**'],
  },
];

Exported Configs

This package exports three configurations:

eslint-config-pyosh (default)

Base JavaScript rules with import plugin configured.

Includes:

• Core ESLint rules
• Import/export rules
• ES6+ features
• Style and formatting rules

eslint-config-pyosh/typescript

TypeScript-specific rules and parser configuration.

Requires:

• @typescript-eslint/eslint-plugin
• @typescript-eslint/parser
• eslint-import-resolver-typescript

Features:

• TypeScript parser and plugin
• Type-aware linting rules
• Import resolver for TypeScript
• Member ordering rules
• Naming conventions

eslint-config-pyosh/prettier

Prettier integration with ESLint.

Requires:

• eslint-config-prettier
• eslint-plugin-prettier

Features:

• Disables conflicting ESLint rules
• Runs Prettier as an ESLint rule
• JSX support

Migration from v3 to v4

What Changed?

1. Configuration Format: .eslintrc.* → eslint.config.js (Flat Config)
2. ESLint Version: 8.x → 9.x
3. @typescript-eslint Version: 6.x → 8.x
4. Removed Rules: Some deprecated rules were replaced

Deprecated Rules Replaced

| Old Rule (v3) | New Rule (v4) | |---------------|---------------| | @typescript-eslint/ban-types | @typescript-eslint/no-empty-object-type@typescript-eslint/no-unsafe-function-type@typescript-eslint/no-wrapper-object-types | | @typescript-eslint/no-empty-interface | @typescript-eslint/no-empty-object-type | | @typescript-eslint/no-var-requires | @typescript-eslint/no-require-imports |

Migration Steps

1. Update dependencies:

   npm install --save-dev \
     eslint@^9.0.0 \
     @typescript-eslint/eslint-plugin@^8.0.0 \
     @typescript-eslint/parser@^8.0.0 \
     globals@^15.0.0 \
     @eslint/js@^9.0.0

2. Delete old config:

   rm .eslintrc.js .eslintrc.json .eslintrc.yml .eslintrc

3. Create new Flat Config:

   Old .eslintrc.js:

   module.exports = {
     extends: [
       'eslint-config-pyosh',
       'eslint-config-pyosh/typescript',
       'eslint-config-pyosh/prettier',
     ],
   };

   New eslint.config.js:

   const pyoshConfig = require('eslint-config-pyosh');
   const pyoshTsConfig = require('eslint-config-pyosh/typescript');
   const pyoshPrettierConfig = require('eslint-config-pyosh/prettier');
   
   module.exports = [
     ...pyoshConfig,
     ...pyoshTsConfig,
     ...pyoshPrettierConfig,
   ];

4. Update npm scripts (if needed):

   {
     "scripts": {
       "lint": "eslint .",
       "lint:fix": "eslint . --fix"
     }
   }

5. Test your configuration:

   npm run lint

Troubleshooting

Import Plugin Not Found

If you see Could not find plugin "import":

Make sure all peer dependencies are installed:

npm install --save-dev eslint-plugin-import

TypeScript Parser Issues

If you see parser errors with TypeScript files:

1. Ensure tsconfig.json exists in your project root
2. Check that TypeScript files are matched by the config
3. Verify @typescript-eslint/parser is installed

Prettier Conflicts

If you see style conflicts between ESLint and Prettier:

1. Make sure eslint-config-prettier is the last config in your array
2. Update your Prettier config to match your style preferences

Contributing

Issues and pull requests are welcome! Please visit the GitHub repository.

License

MIT © pyo-sh