Border Radius: Invalid styles when unit is change without supplying value

[aaronrobertshaw]

Description

It is possible to generate invalid border-radius styles for blocks adopting the border-radius block support. The invalid styles consist of only a CSS unit e.g. border-radius: rem;

The BorderRadiusControl was originally built following the BoxControl which suffered the same issue. The related PR fixing this for the BoxControl can be found in: #33444

Step-by-step reproduction instructions

1. Edit a post in the block editor
2. Add a group block and select it
3. Within the sidebar, change the border-radius unit without supplying any value
4. Switch to the code editor view and you'll find that the block's style object contains a css-unit-only value for radius
5. Switch back to the visual editor and add some further content inside the group block
6. Save the post and view it on the front end
7. Inspect the group block element and notice the invalid styles

Screenshots, screen recording, code snippet

Screen.Recording.2022-07-12.at.7.08.40.pm.mp4

Environment info

WP: Latest
Gutenberg: trunk

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