How to unit test a component

Question

I am running unit test on Angular App, But the component is not getting intialized. It needs three paramaters, I will mock the service but what about the first two parameters?

import { HttpClient } from '@angular/common/http';
import { NgxSpinnerService } from 'ngx-spinner';

constructor(private http: HttpClient,
    private spinner: NgxSpinnerService,
    private someService: SomeService) {
    }

Expected: Component should create

Actual: Component is not created

Answer 1

import HttpClientTestingModule for httpClient and add NgxSpinnerModule in your imports too

import { HttpClientTestingModule } from '@angular/common/http/testing';
import { NgxSpinnerModule } from 'ngx-spinner';
...

beforeEach(async(() => {
TestBed.configureTestingModule({
  imports: [
    HttpClientTestingModule, // for httpClient
    NgxSpinnerModule

   ],
   declarations: [ YourComponent],
   providers: [service],
   schemas: [NO_ERRORS_SCHEMA]
 })
 .compileComponents();
 fixture = TestBed.createComponent(YourComponent);
 component = fixture.componentInstance;
}));

Answer 2

It is a component!! you should use this pattern.

import { HttpClientTestingModule } from '@angular/common/http/testing';
import { NgxSpinnerModule } from 'ngx-spinner';
...

beforeEach(async(() => {
TestBed.configureTestingModule({
  imports: [
    HttpClientTestingModule, // for httpClient
    NgxSpinnerModule

   ],
   declarations: [ YourComponent],
   providers: [service],
   schemas: [NO_ERRORS_SCHEMA]
 })
 .compileComponents();
}));

beforeEach(async() => {
  fixture = TestBed.createComponent(AnalyticsComponent);
  component = fixture.componentInstance;


  // @Inputs
  component.metric    = 'sales';


  component.ngOnInit(); // <===== importand
  component.ngAfterViewInit(); // <===== importand
  await fixture.whenStable(); // <===== importand
  fixture.detectChanges(); // <===== importand
});