Helper to use power-assert in Jasmine testing space.

async-power.ts

export function asyncPower(asyncFunction: () => Promise<void>): Function {
  return function (done) {
    asyncFunction()
      .then(() => done())
      .catch(e => done.fail(e.message));
  }
}

testing-sample.ts

// testing for Angular2 component.

import assert from 'power-assert';
import { asyncPower } from './async-power';

describe('test', () => {
  let builder: TestComponentBuilder;

  beforeEach(inject([TestComponentBuilder], (tcb: TestComponentBuilder) => {
    builder = tcb;
  }));

  it('can create', asyncPower(async () => {
    const fixture = await builder.createAsync(Page1Component);
    assert(!!fixture);
  }));

  it('should have text: "page1 content."', asyncPower(async () => {
    const fixture = await builder.createAsync(Page1Component);
    const el = fixture.nativeElement as HTMLElement;
    const CONTENT = 'h4';

    assert(el.querySelector(CONTENT).textContent === '');
    fixture.detectChanges();
    assert(el.querySelector(CONTENT).textContent === 'page1 content.');
  }));

});