Class MyPromise

packages/zone.js/test/common/Promise.spec.ts:96–100

    it('should allow subclassing without Symbol.species', () => {
      class MyPromise extends Promise<any> {
        constructor(fn: any) {
          super(fn);
        }
      }
      expect(new MyPromise(() => {}).then(() => null) instanceof MyPromise).toBe(true);
    });