Sample grpc-web in angular

app.component.ts

import { Component, OnInit } from '@angular/core';
import { grpc } from '@improbable-eng/grpc-web';
import { HelloReply, HelloRequest } from './grpc/src/proto/greet_pb';
import { Greeter } from './grpc/src/proto/greet_pb_service';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
  title = 'ng-grpc-test';

  // This function to be implemented in a service
  getValue(): Promise<HelloReply.AsObject> {
    return new Promise( (resolve, reject) => {
      const param = new HelloRequest();
      param.setName('Wawarts');
      grpc.unary(Greeter.SayHello, {
        request: param,
        host: 'https://localhost:5001',
        onEnd: resp => {
          const { status, message } = resp;
          if (status === grpc.Code.OK && message) {
            var retval = message.toObject() as HelloReply.AsObject;
            resolve(retval);
          } else {
            reject(resp);
          }
        }
      });
    });    
  }

  async getval() : Promise<void> {
    var ret = await this.getValue();
    console.log(ret.message);
  }
  ngOnInit(): void {
    this.getval();
  }
}