Building Custom ComponentHarness Abstractions for Isolated UI Testing

import { ComponentHarness, HarnessPredicate } from '@angular/cdk/testing';
 
export class CustomButtonHarness extends ComponentHarness {
  static hostSelector = 'app-custom-button';
 
  static with(options: { text?: string }): HarnessPredicate<CustomButtonHarness> {
    return new HarnessPredicate(CustomButtonHarness, options)
      .addOption('text', options.text, (harness, text) =>
        HarnessPredicate.stringMatches(harness.getText(), text)
      );
  }
 
  async getText(): Promise<string> {
    const host = await this.host();
    return host.text();
  }
}