ng运行测试返回错误-TypeError：_this.handler.handle不是函数

Question

我创建了角度为5.2.0的c3条形图。一切都很好。但是我只想使用karma和茉莉与进行测试npm run test。但是我遇到了以下问题。我希望它与rxjs函数有关。但是我无法理解错误的核心。请帮助任何人解决此问题。

TypeError: _this.handler.handle is not a function
    at MergeMapSubscriber.project (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/@angular/common/esm5/http.js:1466:80)
    at MergeMapSubscriber.webpackJsonp.../../../../rxjs/_esm5/operators/mergeMap.js.MergeMapSubscriber._tryNext (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/rxjs/_esm5/operators/mergeMap.js:128:1)
    at MergeMapSubscriber.webpackJsonp.../../../../rxjs/_esm5/operators/mergeMap.js.MergeMapSubscriber._next (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/rxjs/_esm5/operators/mergeMap.js:118:1)
    at MergeMapSubscriber.webpackJsonp.../../../../rxjs/_esm5/Subscriber.js.Subscriber.next (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/rxjs/_esm5/Subscriber.js:92:1)
    at ScalarObservable.webpackJsonp.../../../../rxjs/_esm5/observable/ScalarObservable.js.ScalarObservable._subscribe (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/rxjs/_esm5/observable/ScalarObservable.js:51:1)
    at ScalarObservable.webpackJsonp.../../../../rxjs/_esm5/Observable.js.Observable._trySubscribe (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/rxjs/_esm5/Observable.js:172:1)
    at ScalarObservable.webpackJsonp.../../../../rxjs/_esm5/Observable.js.Observable.subscribe (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/rxjs/_esm5/Observable.js:160:1)
    at MergeMapOperator.webpackJsonp.../../../../rxjs/_esm5/operators/mergeMap.js.MergeMapOperator.call (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/rxjs/_esm5/operators/mergeMap.js:92:1)
    at Observable.webpackJsonp.../../../../rxjs/_esm5/Observable.js.Observable.subscribe (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/rxjs/_esm5/Observable.js:157:1)
    at FilterOperator.webpackJsonp.../../../../rxjs/_esm5/operators/filter.js.FilterOperator.call (http://localhost:9876/_karma_webpack_/webpack:/C:/Workspace/datawens-master/node_modules/rxjs/_esm5/operators/filter.js:61:1)

Answer 1

我能够通过在 app.module.ts 中进行以下更改来解决此问题。希望这可以帮助。

import { HttpClient } from '@angular/common/http';
import { HttpClientModule } from '@angular/common/http';
...
...

@NgModule({
  declarations: [
    MyApp,
    HomePage,
    CameraPage,
  ],
  imports: [
    BrowserModule,
//  HttpClient,
   HttpClientModule,