How to access @Input property in angular unit test

Question

I am writing a jest unit tests for a simple angular component which have @Input property.

Here is my component

import { Component, OnInit, Input } from '@angular/core';

@Component({
  selector: 'app-title',
  template: '<h2 id="title" class="title">{{title}}</h2>',
  styleUrls: ['./title.component.scss'],
})
export class TitleComponent implements OnInit {

  @Input() title;
  constructor() { }

  ngOnInit() {
  }

}

My unit test file

describe('TitleComponent', () => {
  let component: TitleComponent;
  let fixture: ComponentFixture<TitleComponent>;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [
      ],
      declarations: [TitleComponent]
    })
      .compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(TitleComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should create', () => {
    expect(component).toBeTruthy();
  });

  it('should show TEST INPUT', () => {
    component.title = 'test title';
    fixture.detectChanges();
    const input = fixture.nativeElement.querySelector('h2').innerText;

    console.log(input);
    expect(input).toEqual('test title');
  });
});

The console.log(input) is always undefined and my test case is failing. What I doing wrong here?🤔

Answer 1

It should be innerHTML or textContent instead of innerText. Then it works.

fixture.nativeElement.querySelector('h2').innerHTML;

The reason is that jest uses JSDom and in JSDom the innerText property is not implemented yet. innerText implementation #1245