角度对象变化检测

Angular如何检测对象的变化？我有以下示例：

user.component.ts：

@Component({
  selector: 'app-user',templateUrl: './user.component.html',styleUrls: ['./user.component.css'],})
export class UserComponent implements OnInit {

  private _users: User[];
  set users(users: User[]) {
    this._users = users;
  }

  get users(): User[] {
    return this._users;
  }

  constructor() {}

  addUserToTheList(user: User) {

    // this won't be detected as a change to the object
    this.users.push(user);

    // on the other hand,this will
    let userList: User[] = this.users;
    userList.push(user);
    this.users = userList;

  }
}

这是否意味着我必须完全替换对象以触发更改检测,或者我在某种程度上完全忽略了这一点？或者它可能是第三方库(Clarity Design System)的问题