不要在框架 NestJS 中通过 e2e 测试

Question

我使用NestJS框架。使用@nestjs/typeorm 时，我为用户创建了一个存储库。使用这种方法创建存储库，我的e2e 测试. 使用数据库时，所有数据都成功保存。连接没有问题。这是我的文件：

app.module.ts

import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';
import { Connection } from 'typeorm';
import { AuthModule } from './modules/auth/auth.module';

@Module({
  imports: [
    TypeOrmModule.forRoot(),
    AuthModule,
  ],
})
export class AppModule {
  constructor(private readonly connection: Connection) { }
}

auth.module.ts

import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';
import { AuthService } from './auth.service';
import { AuthController } from './auth.controller';
import { Users } from '../../entity/Users';

@Module({
  imports: [TypeOrmModule.forFeature([Users])],
  controllers: [AuthController],
  providers: [AuthService],
})
export class AuthModule {}

auth.service.ts

...
      // my repo
      constructor(
        @InjectRepository(Users)
        private readonly usersRepository: Repository<Users>,
      ) { }
...

app.e2e-spec.ts

import { INestApplication } from '@nestjs/common';
import { Test } from '@nestjs/testing';
import * as request from 'supertest';
import { AppModule } from './../src/app.module';

describe('AppController (e2e)', () => {
  let app: INestApplication;

  beforeAll(async () => {
    const moduleFixture = await Test.createTestingModule({
      imports: [AppModule],
    }).compile();

    app = moduleFixture.createNestApplication();
    await app.init();
  });

  it('/ (GET)', () => {
    return request(app.getHttpServer())
      .get('/')
      .expect(404)
      .expect('{"statusCode":404,"error":"Not Found","message":"Cannot GET /"}'); //todo fix me
  });
});

一切都是按照文档编写的。当您运行npm run test:e2e 时，控制台给出以下错误：

> project@0.0.0 test:e2e 
> jest --config ./test/jest-e2e.json

[Nest] 7206   - 2/2/2019, 5:06:52 PM   [TypeOrmModule] Unable to connect to the database. Retrying (1)...
Error: getaddrinfo ENOTFOUND postgres postgres:5432
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:57:26)
[Nest] 7206   - 2/2/2019, 5:06:55 PM   [TypeOrmModule] Unable to connect to the database. Retrying (2)... +3234ms
Error: getaddrinfo ENOTFOUND postgres postgres:5432
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:57:26)
 FAIL  test/app.e2e-spec.ts (6.198s)
  AppController (e2e)
    ? / (GET) (6ms)

  ? AppController (e2e) › / (GET)

    Timeout - Async callback was not invoked within the 5000ms timeout specified by jest.setTimeout.

      at mapper (../node_modules/jest-jasmine2/build/queue_runner.js:41:52)

  ? AppController (e2e) › / (GET)

    TypeError: Cannot read property 'getHttpServer' of undefined

      17 |
      18 |   it('/ (GET)', () => {
    > 19 |     return request(app.getHttpServer())
         |                        ^
      20 |       .get('/')
      21 |       .expect(404)
      22 |       .expect('{"statusCode":404,"error":"Not Found","message":"Cannot GET /"}'); // todo fix me

      at Object.<anonymous> (app.e2e-spec.ts:19:24)

请帮我！

Answer 1

如果你想用模拟编写 e2e 测试，你不需要导入AppModule你只应该导入你的AppControllerand AppService，这样你就可以避免连接到你的数据库并使用模拟来测试整个应用程序流程。

import { INestApplication } from '@nestjs/common';
import { Test } from '@nestjs/testing';
import * as request from 'supertest';
import { AppController } from './../src/app.controller';
import { AppService } from './../src/app.service';

describe('AppController (e2e)', () => {
  let app: INestApplication;

  beforeAll(async () => {
    const moduleFixture = await Test.createTestingModule({
      imports: [],
      controllers: [AppController],
      providers: [AppService],
    }).compile();

    app = moduleFixture.createNestApplication();
    await app.init();
  });

  it('/ (GET)', () => {
    return request(app.getHttpServer())
      .get('/')
      .expect(404)
      .expect('{"statusCode":404,"error":"Not Found","message":"Cannot GET /"}'); //todo fix me
  });
});

通过这种方法，您可以获得一个干净的测试模块，而无需TypeOrmModule. 注意：如果你需要模拟服务，Test有一个方法overrideProvider来覆盖你的服务和方法，比如useClass，useValue或者useFactory提供你的模拟。

如果您想编写一个集成测试以确认所有这些都正常工作，您可以覆盖您的配置TypeOrmModule，将其传递给具有新数据库配置的测试模块，如本文所述。

我希望我有所帮助。祝你好运和问候。