如何对使用router.paramMap的Angular 4组件进行单元测试 [英] How to unit test a Angular 4 component which uses router.paramMap

问题描述

我是角度4的新手，试图从单元测试中测试一个角度4特征router.paramMap，以下面的方式读取路径参数并在我的应用程序中按预期工作。

I m new to angular 4 and trying to test one of the angular 4 feature router.paramMap from unit tests, Reading route params in fallowing way and working as expected in my application.

constructor(private router:Router, private actRoute:ActivatedRoute) {
}

ngOnInit() {
    this.router.paramMap.subscribe(params => {
        params.get(id);
    })
......
}

但是在运行单元测试的时候，即使我通过传递路径参数，我也得到错误，表示无法调用未定义的订阅方法。

But while running unit test, i m getting error which says cannot call subscribe method of undefined even though i m passing passing route param as below.

{
  provide: ActivatedRoute,
  useValue: { params: Observable.of({id: 1}) }
}

请建议

推荐答案

您需要提供 paramMap 而不是 params 。 paramMap 的类型应为 ParamMap 来自 @ angular / router ，所以普通对象可以使用方法 convertToParamMap（）从 @angular转换为 ParamMap /路由。

You need to provide paramMap instead of params. paramMap should be of type ParamMap from @angular/router, so normal object can be converted to ParamMap using the method convertToParamMap() from @angular/routing.

您可以提供如下的模拟ActivatedRoute：

You can provide the mock ActivatedRoute like below:

import { convertToParamMap} from '@angular/router';
....
.....

{
      provide: ActivatedRoute,
      useValue: { paramMap: Observable.of(convertToParamMap({id: 1})) }
}

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