NestJS中FileUploadService测试报错求助：求正确测试方法

问题代码 #

service.ts #

@Injectable()
export class FileUploadService {
  private readonly logger = new Logger(FileUploadService.name);

  constructor(private readonly httpService: HttpService) {}
}

spec.ts #

beforeEach(async () => {
  const app: TestingModule = await Test.createTestingModule({
    imports: [],
    providers: [FileUploadService],
  }).compile();

  fileService = app.get<FileUploadService>(FileUploadService);
});

报错原因 #

测试模块无法解析HttpService依赖，因为FileUploadService构造函数注入了HttpService，但测试配置中未提供该服务的实例或模拟对象。HttpService来自@nestjs/axios的HttpModule，测试时必须显式声明其依赖。

解决方案 #

方案1：模拟HttpService（单元测试推荐） #

在测试模块的providers中提供一个模拟的HttpService，覆盖真实依赖：

beforeEach(async () => {
  const app: TestingModule = await Test.createTestingModule({
    providers: [
      FileUploadService,
      {
        provide: HttpService,
        useValue: {
          // 根据service实际调用的方法添加对应模拟实现
          post: jest.fn().mockResolvedValue({ data: {} }),
          get: jest.fn().mockResolvedValue({ data: {} })
        }
      }
    ],
  }).compile();

  fileService = app.get<FileUploadService>(FileUploadService);
});

方案2：导入HttpModule（集成测试场景） #

若需使用真实的HttpService，可直接导入HttpModule：

import { HttpModule } from '@nestjs/axios';

beforeEach(async () => {
  const app: TestingModule = await Test.createTestingModule({
    imports: [HttpModule],
    providers: [FileUploadService],
  }).compile();

  fileService = app.get<FileUploadService>(FileUploadService);
});

内容的提问来源于stack exchange，提问作者buddy little