ESLint Configuration

ESLint Configuration

pjt comes with flexible ESLint configurations that you can customize to your needs.

Available configurations

Recommended

Basic configuration with recommended rules.

eslint.config.js

import pjt from 'pjt/eslint';

export default [
  ...pjt.configs.recommended
];

Strict

Stricter configuration for maximum code quality.

import pjt from 'pjt/eslint';

export default [
  ...pjt.configs.strict
];

Minimal

Minimal configuration with basic rules.

import pjt from 'pjt/eslint';

export default [
  ...pjt.configs.minimal
];

Module structure

ESLint configurations are organized in src/eslint/:

src/eslint/
├── index.ts      # Main export
├── config.ts     # Base configurations
├── configs.ts    # Named configurations
├── constants.ts  # Constants
├── ignores.ts    # Ignore patterns
└── rules.ts      # Custom rules

Customizing rules

Adding custom rules

import pjt from 'pjt/eslint';

export default [
  ...pjt.configs.recommended,
  {
    rules: {
      'no-console': 'warn',
      'prefer-const': 'error'
    }
  }
];

Override for specific files

export default [
  ...pjt.configs.recommended,
  {
    files: ['**/*.test.js', '**/*.spec.js'],
    rules: {
      'no-console': 'off'
    }
  }
];

TypeScript support

For TypeScript projects:

import pjt from 'pjt/eslint';
import tseslint from 'typescript-eslint';

export default [
  ...pjt.configs.recommended,
  ...tseslint.configs.recommended
];

React/JSX support

For React projects:

import pjt from 'pjt/eslint';
import react from 'eslint-plugin-react';

export default [
  ...pjt.configs.recommended,
  {
    files: ['**/*.jsx', '**/*.tsx'],
    plugins: { react },
    rules: react.configs.recommended.rules
  }
];

Ignore patterns

Configurations automatically ignore:

• node_modules/
• dist/
• build/
• .git/
• Files from .gitignore

Additional ignore patterns

import pjt from 'pjt/eslint';

export default [
  ...pjt.configs.recommended,
  {
    ignores: [
      'coverage/',
      'docs/'
    ]
  }
];

Editor integration

VS Code

Add to .vscode/settings.json:

{
  "eslint.experimental.useFlatConfig": true,
  "eslint.configFile": "eslint.config.js"
}

WebStorm/IntelliJ

ESLint will automatically detect the configuration.

CLI commands

Checking files

# Check all files
npx eslint .

# Check specific files
npx eslint src/

# Auto fix
npx eslint . --fix

Best practices

1. Use flat config

pjt uses the new flat config format for better performance.

2. Organize by file types

export default [
  ...pjt.configs.recommended,
  {
    files: ['**/*.js'],
    rules: { /* JS rules */ }
  },
  {
    files: ['**/*.ts'],
    rules: { /* TS rules */ }
  }
];

3. Use extends for sharing

shared-config.js

export const sharedRules = {
  'no-console': 'warn'
};

// eslint.config.js
import { sharedRules } from './shared-config.js';
import pjt from 'pjt/eslint';

export default [
  ...pjt.configs.recommended,
  { rules: sharedRules }
];

Troubleshooting

”Cannot find config”

// Check if file is in root
ls -la eslint.config.js

// Check syntax
node -c eslint.config.js

Rules not applied

// Check files pattern
{
  files: ['**/*.js'], // Don't forget **
  rules: { ... }
}

Slow linting

• Use .eslintignore
• Limit files patterns
• Exclude node_modules