NGUnitTestToturial.md

Input Unit test

it('should correctly render the passed @Input value', () => {
  component.message = 'Enter a new title'; // input value modify
  fixture.detectChanges(); // make change
  const compiled = fixture.debugElement.nativeElement; // compiled component
  expect(compiled.querySelector('p').textContent).toBe('Enter a new title'); // component content verify
});

Output Unit test

it('should correctly @Output value of text input in component', () => {
  spyOn(component.changeTitleEvent, 'emit'); // emit spy
  const button = fixture.nativeElement.querySelector('button');
  fixture.nativeElement.querySelector('input').value = 'A new title'; // 2
  const inputText = fixture.nativeElement.querySelector('input').value;
  
  button.click(); // 3
  fixture.detectChanges();
 
  expect(component.changeTitleEvent.emit).toHaveBeenCalledWith(inputText); // 4
});