List View: Slow group deletion

[gwwar]

Description

In larger posts, if we delete nested blocks we can see the block icon and title disappearing before the rows are removed. Ideal behavior would quickly remove all deleted nodes in the list view.

Note that we can see a "fast" delete if we perform an action like, undo, then delete, or paste then delete.

I dug a bit into this one, and what's happening is that the clientIdsTree in ListView is only updated after all child buttons/block titles update. 🤔 I didn't have much luck with triggering a parent update, even when selecting for additional data like block order. We may want to dig into why behavior is different for a paste -> delete, or undo -> delete.

Step-by-step reproduction instructions

1. Open the post editor
2. Open list view
3. Make sure the post is somewhat larger, with a lot of nested content. (Drag a few patterns)
4. Delete a block with a lot of children

Expected: The rows are quickly removed in one go.
Actual: The block icon and title disappears first. Removal of rows is slow.

Screenshots, screen recording, code snippet

slow.remove.mp4

Environment info

Gutenberg master (3f2593f)

Pre-checks

• I have searched the existing issues.
• I have tested with all plugins deactivated except Gutenberg.

[gwwar]

This one should be fixed by #34519