Jasmin + karma：“错误：模块‘DynamicTestModule’导入了意外的值‘HttpClient’。请添加 @NgModule 注释。”

我使用 jasmine 作为测试框架，使用 karma 作为测试运行程序。我正在尝试创建一个 HttpClient 对象，以便我可以创建一个服务作为该对象的依赖项：

TestBed.configureTestingModule({
    declarations: [HttpClient],
    imports: [HttpClient],
    providers: [HttpClient]
});
TestBed.get(HttpClient);

但我收到以下错误：

错误：模块“DynamicTestModule”导入了意外值“HttpClient”。请添加@NgModule注释。

有谁知道如何解决这个问题？

遵循所有代码：

import { I18nService } from "../../services/i18n.service";
import { TestBed, inject, async } from "@angular/core/testing";
import { EditionHistoryEventsModel } from "./dropdown.edition.history.events.model";
import { HttpClient } from "@angular/common/http";
import { TestUtil } from "../../utils/test.uti";



describe('DropDownEditionHistoryItemModel', () => {
    let i18nService: I18nService;
     
    beforeAll(() => {
        TestBed.configureTestingModule({
            declarations: [HttpClient],
            imports: [HttpClient],
            providers: [HttpClient]
        });
        i18nService = TestUtil.geti18nService(TestBed.get(HttpClient));
    });
    it('asdasd', () => {
        let model: EditionHistoryEventsModel = new EditionHistoryEventsModel(i18nService);
        expect(true).toBeTruthy();
    });
});

当您尝试在文件中包含组件、指令或管道以外的内容时，会引发编译错误。declarations array.

我重构了您的测试规范以删除HttpClient从声明模块中导入HttpClientTestingModule因为它比其他产品有一些显着的优势HttpClientModule for testing https://medium.com/netscape/testing-with-the-angular-httpclient-api-648203820712，并使用稍微不同的模式来创建您的实例I18nService传递给你的模型类。

import { HttpClientTestingModule } from '@angular/common/http/testing';

    describe('TestSpec', () => {

    let intlService = I18nService;

    beforeAll(() => {
        TestBed.configureTestingModule({
            declarations: [],
            imports: [HttpClientTestingModule],
            providers: [I18nService]
    });

    i18nService = TestBed.Get(I18nService);
});