Quick inserter: hard to initiate quick inserter after a few times using it

[annezazu]

Using WordPress 6.6.2 and Gutenberg 19.1 in a playground instance, I noticed that, after a first few times, the quick inserter suddenly becomes very hard to initiate. I can't quite understand why but here's a longer video showing how suddenly the same areas where I could use the quick inserter no longer cause it to appear:

quick.inserter.not.appearing.mp4

I can reliably replicate it using TT4 and just clicking around and trying to get it to appear.

[Mamaduka]

Thanks, @annezazu! This is an interesting issue.

Did you also notice any performance degradation? We have some reports related to Inserter + Pattern performance, and I wonder if they are related. See: #64732.

A possible fix will ship with Gutenberg 19.2 - #64902.

[annezazu]

I didn’t notice anything with performance when I was clicking around! It could be that that’s the underlying cause though but it wasn’t discernible to me.

[Mamaduka]

I can also reproduce the issue on the Gutenberg trunk, but I'm having trouble finding a consistent way to do it.

I tracked down the bug to the useInBetweenInserter hook. The openRef.current is set to true permanently, which prevents any other in-between inserters from displaying. Unfortunately, I'm still not sure what is causing this behavior.

gutenberg/packages/block-editor/src/components/block-list/use-in-between-inserter.js

Lines 45 to 49 in cc133bf

	// openRef is the reference to the insertion point between blocks.
	// If the reference is not set or the insertion point is already open, return.
	if ( openRef === undefined || openRef.current ) {
	return;
	}

Update: I think I found a consistent way to reproduce the bug. It looks like the onSelectOrClose is never called when moving focus to a different block on canvas.

1. Create a page.
2. Add a couple of paragraphs.
3. Open in-between inserter.
4. Move the focus to a different block without closing the inserter.
5. Notice that the inserter no longer appears when hovering between the blocks.

Screencast

CleanShot.2024-09-10.at.13.29.30.mp4

[Mamaduka]

This is fixed on the trunk. See: #65208.