app.component.ts

export class AppComponent {
  readonly bot: User = {
    id: 0,
    name: "bot"
  };
  user: User = { id: Date.now().toString() };

  messages: Message[] = [
    {
      author: this.bot,
      timestamp: new Date(),
      text: "Hello! Please enter a name in order to start a chat"
    }
  ];
}