angular - `this.appInits[i] is not a function` 错误发生在 `APP_INITIALIZER`

Question

我正在尝试一个简单的 APP_INITIALIZER使用我的 angular 应用程序，但出现错误
this.appInits[i] is not a function - 无法弄清楚问题。

这是我的应用程序模块:

import { NgModule, APP_INITIALIZER  } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpClientModule, HttpClient, HTTP_INTERCEPTORS } from '@angular/common/http';


export function onAppInit1(){
  return new Promise((resolve,reject) => {
    return setTimeout(() => resolve(true), 5000);
  })
}

@NgModule({
  declarations: [
          AppComponent,
          SignInComponent
    ],
  imports: [

  ],
  providers: [
    {
      provide:APP_INITIALIZER,
      useFactory:onAppInit1,//getting error
      multi: true
    },
    {
      provide: HTTP_INTERCEPTORS,
      useClass: InsertAuthTokenInterceptor,
      multi: true
    }
  ],

  bootstrap: [AppComponent]
})
export class AppModule { }

Answer 1

onAppInit1 应该返回一个返回 promise 的函数

export function onAppInit1(){
  return ()  => { 
    return new Promise((resolve,reject) => {
      return setTimeout(() => resolve(true), 5000);
    })
  }
}