Component Unit Testing with Angular Component Harnesses

import { ComponentFixture, TestBed } from '@angular/core/testing';
import { TestbedHarnessEnvironment } from '@angular/cdk/testing/testbed';
import { MatButtonHarness } from '@angular/material/button/testing';
import { SubmitButtonComponent } from './submit-button.component';
 
describe('SubmitButtonComponent', () => {
  let fixture: ComponentFixture<SubmitButtonComponent>;
  
  beforeEach(async () => {
    await TestBed.configureTestingModule({
      imports: [SubmitButtonComponent]
    }).compileComponents();
    fixture = TestBed.createComponent(SubmitButtonComponent);
  });
 
  it('should disable submit button when processing', async () => {
    const loader = TestbedHarnessEnvironment.loader(fixture);
    const buttonHarness = await loader.getHarness(MatButtonHarness.with({ text: 'Submit' }));
    
    fixture.componentInstance.isProcessing.set(true);
    const isDisabled = await buttonHarness.isDisabled();
    
    expect(isDisabled).toBe(true);
  });
});