wp_enqueue_block_style no longer adds styles in the site editor if Gutenberg 13.0 is active

[carolinan]

Description

In WordPress 5.9x, a block theme can use wp_enqueue_block_style to add additional stylesheets to blocks.

But when Gutenberg 13.0 is active, the styles are no longer applied in the site editor or template editor, only in the block editor and the front.

Step-by-step reproduction instructions

Activate a theme that uses wp_enqueue_block_style.

1. In the site editor, add one of the styled blocks.
2. Save and view the front.
3. Compare the Site Editor and front and see that the styles do not match.

Screenshots, screen recording, code snippet

No response

Environment info

WordPress 5.9.3
Gutenberg 13.0

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[carolinan]

I confirmed that this is still happening with 6.0-beta2-53249 and current Gutenberg trunk.
Does not happen with 6.0-beta2-53249 only.
Does not happen on 6.0-beta2-53249 or 5.93 with Gutenberg 12.9.

Can someone confirm if this was an intentional change or a bug?
I don't know who to ask, @Mamaduka?

[Mamaduka]

Pinging @adamziel and @gziolo.

I’m offline today, but can have a look tomorrow.

[gziolo]

Does not happen with 6.0-beta2-53249 only.

It doesn't look like it's an issue with WordPress core.

[Mamaduka]

I am marking this as a regression. I will try to debug the issue later this week.

[Gierand]

@carolinan, @Mamaduka when enqueueing stylesheets via add_editor_style, they are also noticeably absent.

[ndiego]

Just confirmed this no longer works in 6.0 RC1 (without Gutenberg active). I'm elevating this issue as it's a breaking change.

[ndiego]

cc @annezazu @priethor @gziolo @adamziel Unfortunately, this is another one. It's a significant breaking change that we need to get fixed before the 6.0 release.

[gziolo]

As noted in #40562 (comment). It must be something with passing styles to the iframed editor. The following sentence is a great confirmation of that:

But when Gutenberg 13.0 is active, the styles are no longer applied in the site editor or template editor, only in the block editor and the front.

[carolinan]

Possibly related:
#40603

[ndiego]

@carolinan yup, that looks to be the same issue. So it appears this was introduced in 13.0, I'm going to start going through the changelog there.

[carolinan]

wp_enqueue_block_style uses enqueue_block_assets to add editor styles, Gutenberg active, I need to combine wp_enqueue_block_style with add_editor_style to add CSS to the site editor.

[carolinan]

:/ OK adding add_editor_style no longer works with 6.0 Rc1. It did work in beta 2.

[gziolo]

A potential fix is ready for testing: #40842.