Zustandsbehaftete unveränderliche Array-Operationen in signalbasierten Services

import { Injectable, signal, computed } from '@angular/core';
 
export interface TaskRecord {
  readonly id: string;
  readonly priority: number;
  readonly title: string;
}
 
export abstract class BaseCollectionModel<T extends { id: string }> {
  protected readonly itemsSignal = signal<readonly T[]>([]);
  readonly items = this.itemsSignal.asReadonly();
  readonly count = computed(() => this.itemsSignal().length);
 
  abstract sortEntries(): void;
}
 
@Injectable({ providedIn: 'root' })
export class TaskManagerService extends BaseCollectionModel<TaskRecord> {
  sortEntries(): void {
    this.itemsSignal.update(current => 
      current.toSorted((a, b) => b.priority - a.priority)
    );
  }
 
  removeTaskById(targetId: string): void {
    this.itemsSignal.update(current => {
      const index = current.findIndex(task => task.id === targetId);
      return index !== -1 ? current.toSpliced(index, 1) : current;
    });
  }
}