backend/testing-guide

后端测试编写指南

测试要求（强制）

职责边界：Backend Agent 是测试的编写者，QA Agent 是测试的验证者。

测试金字塔

测试类型	占比	要求
单元测试	~70%	Service 层、业务逻辑必须有测试
集成测试	~20%	API 端点、数据库操作测试
E2E 测试	~10%	必须编写，完整 API 流程测试

单元测试编写

Service 层测试

// services/userService.test.ts
import { UserService } from './userService';
import { UserRepository } from '../repositories/userRepository';

jest.mock('../repositories/userRepository');

describe('UserService', () => {
  let userService: UserService;
  let userRepository: jest.Mocked<UserRepository>;

  beforeEach(() => {
    userRepository = new UserRepository() as jest.Mocked<UserRepository>;
    userService = new UserService(userRepository);
  });

  describe('getById', () => {
    it('returns user when found', async () => {
      const mockUser = { id: '1', name: 'Alice', email: '[email protected]' };
      userRepository.findById.mockResolvedValue(mockUser);

      const result = await userService.getById('1');

      expect(result).toEqual(mockUser);
      expect(userRepository.findById).toHaveBeenCalledWith('1');
    });

    it('throws NotFoundError when user not found', async () => {
      userRepository.findById.mockResolvedValue(null);

      await expect(userService.getById('999')).rejects.toThrow('User not found');
    });
  });

  describe('create', () => {
    it('creates user with valid data', async () => {
      const createData = { name: 'Bob', email: '[email protected]' };
      const mockUser = { id: '2', ...createData };
      
      userRepository.findByEmail.mockResolvedValue(null);
      userRepository.create.mockResolvedValue(mockUser);

      const result = await userService.create(createData);

      expect(result).toEqual(mockUser);
      expect(userRepository.findByEmail).toHaveBeenCalledWith('[email protected]');
      expect(userRepository.create).toHaveBeenCalledWith(createData);
    });

    it('throws ConflictError when email already exists', async () => {
      const createData = { name: 'Bob', email: '[email protected]' };
      userRepository.findByEmail.mockResolvedValue({ id: '1', name: 'Existing', email: '[email protected]' });

      await expect(userService.create(createData)).rejects.toThrow('Email already exists');
    });
  });
});