Optimistic Update with Rollback

function likePhoto(photo: Photo) {
    likedPhotos.update((liked) => {
      liked.add(photo.id);
      return liked;
    });
    const run = likePhotoRequest(photo.id).pipe(
      Effect.tap(() =>
        photos.update((oldPhotos) =>
          oldPhotos.map((p) => {
            if (p.id === photo.id) {
              return { ...p, likes: p.likes + 1 };
            }
            return p;
          }),
        ),
      ),
      notifyError("Error liking photo"),
    );
    Effect.runPromise(run);
  }

function likePhoto(photo: Photo) {
    likedPhotos.update((liked) => {
      liked.add(photo.id);
      return liked;
    });
    const run = likePhotoRequest(photo.id).pipe(
      Effect.tap(() =>
        photos.update((oldPhotos) =>
          oldPhotos.map((p) => {
            if (p.id === photo.id) {
              return { ...p, likes: p.likes + 1 };
            }
            return p;
          }),
        ),
      ),
      notifyError("Error liking photo"),
    );
    Effect.runPromise(run);
  }