Testing Strategies: Unit, Integration, and E2E Testing
April 18, 2024•1 min read
TestingJestE2EQuality Assurance
# Testing Strategies: Unit, Integration, and E2E Testing
Comprehensive testing ensures code quality and prevents regressions. This guide covers testing strategies for modern applications.
## Testing Pyramid
1. **Unit Tests** (70%): Test individual functions/components
2. **Integration Tests** (20%): Test component interactions
3. **E2E Tests** (10%): Test complete user flows
## Unit Testing
```typescript
import { describe, it, expect } from '@jest/globals';
describe('UserService', () => {
it('should create a user', async () => {
const user = await userService.create({
email: 'test@example.com',
name: 'Test User',
});
expect(user.email).toBe('test@example.com');
});
});
```
## Integration Testing
```typescript
describe('UsersController (e2e)', () => {
it('/users (POST)', () => {
return request(app.getHttpServer())
.post('/users')
.send({ email: 'test@example.com', name: 'Test' })
.expect(201);
});
});
```
## E2E Testing
```typescript
import { test, expect } from '@playwright/test';
test('user can create account', async ({ page }) => {
await page.goto('/signup');
await page.fill('[name="email"]', 'test@example.com');
await page.click('button[type="submit"]');
await expect(page.locator('.success')).toBeVisible();
});
```
## Conclusion
A balanced testing strategy catches bugs early and maintains code quality. Invest in testing infrastructure for long-term success.