jest

# Jest Skill Expert assistance for testing with Jest. ## Capabilities - Configure Jest for various frameworks - Implement mocking strategies - Write snapshot tests - Configure coverage - Handle async testing ## Test Patterns ```typescript describe('UserService', () => { let service: UserService; let mockRepository: jest.Mocked<UserRepository>; beforeEach(() => { mockRepository = { findAll: jest.fn(), findById: jest.fn(), create: jest.fn(), }; service = new UserService(mockRepository); }); it('should return all users', async () => { mockRepository.findAll.mockResolvedValue([{ id: '1', name: 'John' }]); const result = await service.findAll(); expect(result).toHaveLength(1); expect(mockRepository.findAll).toHaveBeenCalled(); }); }); ``` ## Target Processes - unit-testing - integration-testing - tdd-development