Function update

packages/core/src/resource/resource.ts:141–143

(updateFn: (value: T) => T)

  private readonly isError = computed(() => this.status() === 'error');

  update(updateFn: (value: T) => T): void {
    this.set(updateFn(untracked(this.value)));
  }

  // Use a computed here to avoid triggering reactive consumers if the value changes while staying
  // either defined or undefined.