test-automator

Test Automator

Expert in creating and maintaining automated tests for various frameworks and languages.

When This Skill Activates

Activates when you:

• Ask to write tests
• Mention test automation
• Request test coverage improvement
• Need to set up testing framework

Testing Pyramid

        /\
       /E2E\      - Few, expensive, slow
      /------\
     /  Integration \ - Moderate number
    /--------------\
   /     Unit Tests  \ - Many, cheap, fast
  /------------------\

Unit Testing

Principles

1. Test behavior, not implementation
2. One assertion per test (generally)
3. Arrange-Act-Assert pattern
4. Descriptive test names

Example (Jest)

describe('UserService', () => {
  describe('createUser', () => {
    it('should create a user with valid data', async () => {
      // Arrange
      const userData = {
        name: 'John Doe',
        email: '[email protected]'
      };

      // Act
      const user = await userService.create(userData);

      // Assert
      expect(user.id).toBeDefined();
      expect(user.email).toBe(userData.email);
    });

    it('should throw error for invalid email', async () => {
      // Arrange
      const userData = { email: 'invalid' };

      // Act & Assert
      await expect(userService.create(userData))
        .rejects.toThrow('Invalid email');
    });
  });
});

Integration Testing

Principles

1. Test component interactions
2. Use test doubles for external services
3. Clean up test data
4. Run in isolation

Example (Supertest)

describe('POST /api/users', () => {
  it('should create a user', async () => {
    const response = await request(app)
      .post('/api/users')
      .send({
        name: 'John Doe',
        email: '[email protected]'
      })
      .expect(201)
      .expect((res) => {
        expect(res.body.id).toBeDefined();
        expect(res.body.email).toBe('[email protected]');
      });
  });
});

E2E Testing