Angular 6 Testing - 参考使用HttpClient的帮助程序的服务

上周我将我们的应用程序从Angular 5.8升级到6.我将HttpModule和Http的使用改为使用HttpClientModule和HttpClient . 到目前为止，前端看起来像预期的那样好 . 只是现在一些服务测试失败了，我正在尝试修复它们 . 基本上我有两种类型的服务：

• 直接使用HttpClient的服务 .

客户服务：

import { HttpClient } from "@angular/common/http";
import { Injectable } from "@angular/core";
import { map } from "rxjs/operators";
import { Observable} from "rxjs";

@Injectable()
export class CustomService {
    constructor(private readonly http: HttpClient) { }

    someMethod(): Observable<boolean> {
        return this.http.get("api/some-url").pipe(
            map(res => <boolean>res) }))
        );
    }
}

• 使用ServiceHelper的服务，该服务使用HttpClient .

客户服务：

import { HttpHeaders } from "@angular/common/http";
import { Injectable } from "@angular/core";
import { Observable } from "rxjs";

import { SomeRequest } from "../Models/SomeRequest";
import { SomeResult } from "../Models/SomeResult";
import { ServiceHelper } from "./../Helpers/servicehelper";

@Injectable()
export class CustomService {
    constructor(readonly serviceHelper: ServiceHelper) { }

    someMethod(): Observable<SomeResult> {
        const request = {} as SomeRequest;
        const headers = new HttpHeaders({ "Content-Type": "application/json" });
        const options = { headers: headers };

        return this.serviceHelper
            .post<SomeRequest, SomeResult>("api/some-url", request, options);
    }
}

ServiceHelper：

import { HttpClient } from "@angular/common/http";
import { Injectable } from "@angular/core";
import { map } from "rxjs/operators";
import { Observable } from "rxjs";

import { Result } from "../Models/Result";

@Injectable()
export class ServiceHelper {
    constructor(readonly http: HttpClient) { }

    post<Req, Res extends Result>(url: string, request: Req, options): Observable<Res> {
        return this.http.post(url, request, options).pipe(
            map(data => (data as any) as Res)
        );
    }
}

第一项服务的测试已经重新开始，通过这样做：

import { TestBed } from "@angular/core/testing";
import { HttpClientTestingModule, HttpTestingController } from "@angular/common/http/testing";
import { HttpResponse } from "@angular/common/http";

import { CustomService } from "./custom.service";

describe("service tests", () => {
    let service: CustomService;
    let httpClient: HttpTestingController;

    beforeEach(() => {
        TestBed.configureTestingModule({
            imports: [HttpClientTestingModule],
            providers: [CustomService]
        });
        service = TestBed.get(CustomService);
        httpClient = TestBed.get(HttpTestingController);
    });

    it("should pass", () => {
        service.someMethod().subscribe(result => {
            expect(result).toBe(true);
        });

        httpClient.expectOne("api/some-url").event(
            new HttpResponse<boolean>({ body: true }));
    });
});

对于第二个服务（使用ServiceHelper），我想在beforeEach语句中执行类似上面的操作 . 我在configureTestingModule中尝试了一些添加提供程序和/或导入的东西，但是大多数情况下我在运行测试后得到了一个StaticInjectorError .

何我可以为第二类服务编写测试？希望有人可以帮助我！