如何在 Karma 中对 forkJoin 进行单元测试

Question

我有一个使用 forkJoin 的代码，它是这样的，

forkJoin(serviceRequests).subscribe((forkResults) => {
                //Do stuff with forkResults here 
});

如何模拟订阅以便也可以评估其中的代码。

我尝试了以下各种方法

spyOn(Observable, 'forkJoin').and.returnValue(of(mockedResults));

Answer 1

// 首先我假设你在像

这样的函数中使用 forkJoin

  func() {
    forkJoin(this.getForkedStreams()).pipe(takeUntil(this.unsubscribe)).subscribe((streams: any[]) => {
      console.log(streams[0]);
      console.log(streams[1]);
      console.log(streams[2]);

      // logs the array objects provided by the streams
    });
  }
  getForkedStreams() {
    return [
      this.service.func1(),
      this.service.func2(),
      this.service.func3()
    ];
  }

// 然后在规范文件中将流数组模拟为

// 模拟如下服务函数：

     let mockService: any;
    mockService = {
  func1: () => {
    return of({
      prop: 'xyz'
    });
  },
  func2: () => {
    return of({
      prop: 'xyz'
    });
  },
  func3: () => {
    return of({
      prop: 'xyz'
    });
  }
};

//服务注入新的 SampleComponent（任何模拟服务）；

   /*
Then, in the actual describe => it block, assert against the values mocked up with the variable with which it would be assigned to.
I am not doing that since it is only the mocking that you've asked and you might want to continue from there
*/

如何在 Karma 中对 forkJoin 进行单元测试

How to unit test forkJoin in Karma

observable

rxjs

karma-jasmine

angular