Angular 6 - NullInjectorError: No provider for HttpClient in unit tests

import { TestBed } from '@angular/core/testing';import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';import {HttpClientModule} from '@angular/common/http';import { myService } from './myservice';describe('myService', () => {      beforeEach(() => TestBed.configureTestingModule({        imports: [HttpClientTestingModule],         providers: [myService]      }));       it('should be created', () => {        const service: myService = TestBed.get(myService);        expect(service).toBeTruthy();       });       it('should have getData function', () => {        const service: myService = TestBed.get(myService);        expect(service.getData).toBeTruthy();       });    });

you should add HttpClient into imports of your module where your component is declared

@NgModule({  declarations: [    MyComponent  ],  imports: [    BrowserModule,    FormsModule,    HttpClientModule  ],  providers: []})export class AppModule { }

import { TestBed } from '@angular/core/testing';import { HttpClientTestingModule } from '@angular/common/http/testing';import { myService } from './myservice';describe('HeaderService', () => {  beforeEach(() => TestBed.configureTestingModule({    imports: [ HttpClientTestingModule ],    providers: [myService]  }));});