Angular fakeAsync test of promise resolution in ngOnInit()

For some reason, my fakeAsync tests will not resolve simple promises. I created a minimal example showing the issue (mostly ng-generated boilerplate).

My component under test contains a simple direct promise resolution in its ngOnInit method:

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

@Component({
  selector: 'app-simple-test',
  templateUrl: './simple-test.component.html',
  styleUrls: ['./simple-test.component.scss']
})
export class SimpleTestComponent implements OnInit {

  constructor() { }

  message: string;

  ngOnInit() {
    Promise.resolve('hello').then((content: string) => this.message = content);
  }

}

I am testing this promise with the following test:

import { async, ComponentFixture, fakeAsync, TestBed, tick } from '@angular/core/testing';

import { SimpleTestComponent } from './simple-test.component';

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

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

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

  it('should display "hello"', fakeAsync(() => {
    tick();
    expect(component.message).toBe('hello');
  }));
});

But the test fails, meaning the promise is not resolved at the time of expect, despite the forced promise resolution via tick().

It works when adding another explicit call to component.ngOnInit() at the beginning of the test. But this results in ngOnInit() being called twice. As far as I know, fixture.detectChanges() in beforeEach() should take care of ngOnInit() anyway.

What am I missing? Why isn't the promise resolved during tick()?