@yourname/jest-config-library

Shared Jest configuration for React component libraries with stricter 95%+ coverage thresholds.

Installation

pnpm add -D @yourname/jest-config-library jest @testing-library/react @testing-library/jest-dom @testing-library/user-event

Usage

Create jest.config.js in your library root:

const baseConfig = require('@yourname/jest-config-library');

module.exports = {
    ...baseConfig,
    // Override as needed
};

What's Different from @yourname/jest-config

Higher Coverage Thresholds

• 95% minimum (vs 90% for apps)
• Published libraries should be exceptionally well-tested

Additional Exclusions

Automatically excludes:

• index.ts files (often just re-exports)
• types.ts files (type-only, no runtime code)
• Storybook static builds

Display Name

Includes library-specific display name for easier debugging in monorepos.

Setup

Same as base config:

// testing/setupTests.ts
import '@testing-library/jest-dom';

// testing/__mocks__/styleMock.js
module.exports = {};

// testing/__mocks__/fileMock.js
module.exports = 'test-file-stub';

Scripts

Add to your library's package.json:

{
  "scripts": {
    "test": "jest",
    "test:watch": "jest --watch",
    "test:coverage": "jest --coverage"
  }
}

Testing Library Components

import { render, screen } from '@testing-library/react';
import { Button } from './Button';

describe('Button', () => {
    it('renders correctly', () => {
        render(<Button>Click me</Button>);
        expect(screen.getByText('Click me')).toBeVisible();
    });
});

License

MIT