Angular Component Testing: ngOnChanges does not fire when using Class syntax #23591

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

@Component({
  selector: 'app-simple',
  template: `<div data-cy="simple">Hi {{ name }}. ngOnChanges fired: {{ ngOnChangesFired }}</div>`,
})
export class SimpleComponent implements OnChanges {
  @Input() name: string | undefined;

  ngOnChangesFired = false;

  ngOnChanges(changes: SimpleChanges): void {
    this.ngOnChangesFired = true;
  }
}

import { SimpleComponent } from './simple.component';

describe(`${SimpleComponent.name}`, () => {

  // This succeeds
  it('should fire ngOnChanges when using template syntax', () => {
    cy.mount(`<app-simple [name]="name"></app-simple>`, {declarations: [SimpleComponent], componentProperties: {name: 'Henk'}});

    cy.get('[data-cy=simple]').should('have.text', 'Hi Henk. ngOnChanges fired: true');
  });

  // This fails
  it('should fire ngOnChanges when using class syntax', () => {
    cy.mount(SimpleComponent, {componentProperties: {name: 'Henk'}});

    cy.get('[data-cy=simple]').should('have.text', 'Hi Henk. ngOnChanges fired: true');
  });

})