Question

我希望能够针对实际数据库测试Nest服务。我知道大多数单元测试应该使用模拟对象，但有时针对数据库本身进行测试也很有意义。

我在SO和GH问题中搜索了Nest，并开始逐步解决所有问题。：-）

我正在尝试从https://github.com/nestjs/nest/issues/363#issuecomment-360105413开始工作。以下是我的单元测试，该测试使用自定义提供程序将存储库传递给我的服务类。

describe("DepartmentService", () => {
  const token = getRepositoryToken(Department);
  let service: DepartmentService;
  let repo: Repository<Department>;

  beforeEach(async () => {
    const module: TestingModule = await Test.createTestingModule({
      providers: [
        DepartmentService,
        {
          provide: token,
          useClass: Repository
        }
      ]
    }).compile();

    service = module.get<DepartmentService>(DepartmentService);
    repo = module.get(token);
  });

一切正常编译，TypeScript看起来很高兴。但是，当我尝试在我的 create实例上执行save或Repository时，基础Repository似乎是未定义的。这是堆栈回溯：

TypeError: Cannot read property 'create' of undefined

  at Repository.Object.<anonymous>.Repository.create (repository/Repository.ts:99:29)
  at DepartmentService.<anonymous> (relational/department/department.service.ts:46:53)
  at relational/department/department.service.ts:19:71
  at Object.<anonymous>.__awaiter (relational/department/department.service.ts:15:12)
  at DepartmentService.addDepartment (relational/department/department.service.ts:56:16)
  at Object.<anonymous> (relational/department/test/department.service.spec.ts:46:35)
  at relational/department/test/department.service.spec.ts:7:71

似乎没有初始化具有TypeORM EntityManager类的Repository实例；此回溯抱怨的是undefined参考。

如何使Repository和EntityManager正确初始化？

谢谢，汤姆。

Answer 1

To initialize typeorm properly, you should just be able to import the TypeOrmModule in your test:

Test.createTestingModule({
  imports: [
   TypeOrmModule.forRoot({
        type: 'mysql',
        // ...
   }),
   TypeOrmModule.forFeature([Department])
  ]

Answer 2

这是采用Kim Kern建议的测试的更新。

describe("DepartmentService", () => {
  let service: DepartmentService;
  let repo: Repository<Department>;
  let module: TestingModule;

  beforeAll(async () => {
    module = await Test.createTestingModule({
      imports: [
        TypeOrmModule.forRoot(),
        TypeOrmModule.forFeature([Department])
      ],
      providers: [DepartmentService]
    }).compile();

    service = module.get<DepartmentService>(DepartmentService);
    repo = module.get<Repository<Department>>(getRepositoryToken(Department));
  });

  afterAll(async () => {
    module.close();
  });

  it("should be defined", () => {
    expect(service).toBeDefined();
  });

  // ...
}

Answer 3

为简单起见，我宁愿不使用@nestjs/testing。

首先，创建一个可重用的帮助器：

/* src/utils/testing-helpers/createMemDB.js */
import { createConnection, EntitySchema } from 'typeorm'
type Entity = Function | string | EntitySchema<any>

export async function createMemDB(entities: Entity[]) {
  return createConnection({
    // name, // let TypeORM manage the connections
    type: 'sqlite',
    database: ':memory:',
    entities,
    dropSchema: true,
    synchronize: true,
    logging: false
  })
}

然后，编写测试：

/* src/user/user.service.spec.ts */
import { Connection, Repository } from 'typeorm'
import { createMemDB } from '../utils/testing-helpers/createMemDB'
import UserService from './user.service'
import User from './user.entity'

describe('User Service', () => {
  let db: Connection
  let userService: UserService
  let userRepository: Repository<User>

  beforeAll(async () => {
    db = await createMemDB([User])
    userRepository = await db.getRepository(User)
    userService = new UserService(userRepository) // <--- manually inject
  })
  afterAll(() => db.close())

  it('should create a new user', async () => {
    const username = 'HelloWorld'
    const password = 'password'

    const newUser = await userService.createUser({ username, password })
    expect(newUser.id).toBeDefined()

    const newUserInDB = await userRepository.findOne(newUser.id)
    expect(newUserInDB.username).toBe(username)
  })
})

请参阅https://github.com/typeorm/typeorm/issues/1267#issuecomment-483775861

Answer 4

我创建了一个测试orm配置

// ../test/db.ts
import { TypeOrmModuleOptions } from '@nestjs/typeorm';
import { EntitySchema } from 'typeorm';

type Entity = Function | string | EntitySchema<any>;

export const createTestConfiguration = (
  entities: Entity[],
): TypeOrmModuleOptions => ({
  type: 'sqlite',
  database: ':memory:',
  entities,
  dropSchema: true,
  synchronize: true,
  logging: false,
});

然后我会在设置测试时使用

// books.service.test.ts
import { Test, TestingModule } from '@nestjs/testing';
import { HttpModule, HttpService } from '@nestjs/common';
import { TypeOrmModule, getRepositoryToken } from '@nestjs/typeorm';
import { Repository } from 'typeorm';

import { BooksService } from './books.service';
import { Book } from './book.entity';
import { createTestConfiguration } from '../../test/db';

describe('BooksService', () => {
  let module: TestingModule;
  let service: BooksService;
  let httpService: HttpService;
  let repository: Repository<Book>;

  beforeAll(async () => {
    module = await Test.createTestingModule({
      imports: [
        HttpModule,
        TypeOrmModule.forRoot(createTestConfiguration([Book])),
        TypeOrmModule.forFeature([Book]),
      ],
      providers: [BooksService],
    }).compile();

    httpService = module.get<HttpService>(HttpService);
    service = module.get<BooksService>(BooksService);
    repository = module.get<Repository<Book>>(getRepositoryToken(Book));
  });

  afterAll(() => {
    module.close();
  });

  it('should be defined', () => {
    expect(service).toBeDefined();
  });

这允许在测试后查询存储库，并确保插入了正确的数据。

Answer 5

我通常为数据库连接导入AppModule，最后在执行测试后关闭连接：

  let service: SampleService;
  let connection: Connection;

  beforeEach(async () => {
    const module: TestingModule = await Test.createTestingModule({
      imports: [AppModule, TypeOrmModule.forFeature([SampleEntity])],
      providers: [SampleService],
    }).compile();

    service = module.get<SampleService>(SampleService);
    connection = await module.get(getConnectionToken());
  });

  afterEach(async () => {
    await connection.close();
  });

针对实际数据库测试NestJS服务

5 个答案: