Angular InjectionToken自定义HTTP配置没有提供程序

我不熟悉因果报应和茉莉花，所以如果这听起来很愚蠢，请原谅我。我有以下代码，我想用它做的是找出下一步需要做什么。我已经在

hello HTTP.service.ts

中的构造函数中注入了

自定义\u HTTP\u CONFIG

，我找不到如何实现这一点的教程，手动注入依赖项，这就是我认为错误消息所抱怨的

测试规范ts

你好http.service.ts

因果报应：错误

---

您可以尝试以下操作：-

let svc: HelloHttpService;    

beforeEach(inject([HelloHttpService], (serviceArg: HelloHttpService) => {
    svc = serviceArg;
}));

---

试着这样做：

import { TestBed, inject } from '@angular/core/testing';

import { HelloHttpService } from './http.service';

describe('HttpService', () => {
    let service : HelloHttpService;

    // mock the service, there we no need to pull in any dependency or need to declare constant for the injector aka CUSTOM_HTTP_CONFIG
    const mockHelloHttpService() = { } as HelloHttpService;

    beforeEach(() => {
        TestBed.configureTestingModule({
            providers: [{
             provide: HelloHttpService,
             useValue: mockHelloHttpService, // must do this, or it will try to find the injector token in the custom http service
             // which the reason why this error occurred.
         }],
        });
    });
it('should be created', inject([HelloHttpService], (service: HelloHttpService) => {
    expect(service).toBeTruthy();
}));
});

---

这是我以前尝试过的方法之一，它在这一行中抱怨

fixture=TestBed.createComponent（LogoutComponent）async

进行了相同的尝试？不，我们可以将async与injector一起使用吗？我没见过有人用过它。

Failed: Uncaught (in promise): Error: StaticInjectorError(DynamicTestModule)[HelloHttpService -> InjectionToken Custom HTTP Config]: 
  StaticInjectorError(Platform: core)[HelloHttpService -> InjectionToken Custom HTTP Config]: 
    NullInjectorError: No provider for InjectionToken Custom HTTP Config!
Error: StaticInjectorError(DynamicTestModule)[HelloHttpService -> InjectionToken Custom HTTP Config]: 
  StaticInjectorError(Platform: core)[HelloHttpService -> InjectionToken Custom HTTP Config]: 
    NullInjectorError: No provider for InjectionToken Custom HTTP Config!
    at _NullInjector.webpackJsonp../node_modules/@angular/core/esm5/core.js._NullInjector.get (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:1003:1)
    at resolveToken (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:1301:1)

let svc: HelloHttpService;    

beforeEach(inject([HelloHttpService], (serviceArg: HelloHttpService) => {
    svc = serviceArg;
}));

import { TestBed, inject } from '@angular/core/testing';

import { HelloHttpService } from './http.service';

describe('HttpService', () => {
    let service : HelloHttpService;

    // mock the service, there we no need to pull in any dependency or need to declare constant for the injector aka CUSTOM_HTTP_CONFIG
    const mockHelloHttpService() = { } as HelloHttpService;

    beforeEach(() => {
        TestBed.configureTestingModule({
            providers: [{
             provide: HelloHttpService,
             useValue: mockHelloHttpService, // must do this, or it will try to find the injector token in the custom http service
             // which the reason why this error occurred.
         }],
        });
    });
it('should be created', inject([HelloHttpService], (service: HelloHttpService) => {
    expect(service).toBeTruthy();
}));
});