Create user on firebase from another user.

user-management.service.ts

import { Injectable } from "@angular/core";
import { User } from "../models/user.model";
import { AngularFireList, AngularFireDatabase } from "@angular/fire/database";
import * as firebase from "firebase";
import { UserService } from "./user.service";
import { AngularFireAuth } from "@angular/fire/auth";
import { environment } from "../../environments/environment";

@Injectable({
  providedIn: "root"
})
@Injectable()
export class UserManagementService {
  private dbPath = "/users";
  currentUser: User;

  usersRef: AngularFireList<any>;

  constructor(
    private afDb: AngularFireDatabase,
    private userService: UserService,
    private afAuth: AngularFireAuth
  ) {
    this.userService.getCurrentUser().then(user => {
      this.currentUser = user;
    });

    this.usersRef = afDb.list(this.dbPath);
  }

  create(user: User, credentials): Promise<any> {
    return new Promise<any>((resolve, reject) => {
      const authApp = firebase.initializeApp(
        environment.firebase,
        "CreateUserApp"
      );
      authApp
        .auth()
        .createUserWithEmailAndPassword(credentials.email, credentials.password)
        .then(
          res => {
            user.key = res.user.uid;
            this.usersRef.update(res.user.uid, user).then(
              resRef => {
                authApp.auth().signOut();
                resolve(resRef);
                authApp.delete();
              },
              errRef => {
                reject(errRef);
                authApp.delete();
              }
            );
          },
          err => reject(err)
        );
    });
  }
}