How to call a function after promise

Question

JavaScript noobie here. Lacking knowledge of an important design pattern.

this.getEventData(); < How can I call that function after the promise is resolved? So then I can remove the noobie setTimeout ?

  public onInit(): Promise<void> {
    return super.onInit().then(_ => {
      new Promise<void>((resolve: () => void, reject: (error: any) => void): void => {
        this.context.aadHttpClientFactory
          .getClient(APIAppRegID)
          .then((client: AadHttpClient): void => {
            this.httpClient = client;
            resolve();
          }, err => reject(err));
      });
      setTimeout(() => {
        this.getEventData();
      }, 1500);
    });
  }

Answer 1

async/await version :

async onInit(): Promise<void> {
  await super.onInit();
  this.httpClient = await this.context.aadHttpClientFactory.getClient(APIAppRegID);
  this.getEventData();
}