Edge case: The editors break if the pattern category taxonomy is unregistered

[carolinan]

Description

The wp_pattern_category is a taxonomy registered on the wp_block post type.

It can be unregistered using unregister_taxonomy_for_object_type

If the taxonomy is unregistered, the editors break with the following JavaScript error:

react-dom.min.js?ver=18:1 TypeError: Cannot read properties of undefined (reading 'map')
    at Pe (private-selectors.js:333:47)
    at private-selectors.js:394:6
    at Array.map (<anonymous>)
    at private-selectors.js:393:6
    at s (rememo.js:270:18)
    at r (factory.js:56:10)
    at r (index.js:249:13)
    at selectors.js:2482:22
    at s (rememo.js:270:18)
    at r (factory.js:56:10)

I am not sure what the use case would be: But since unregistering is supported by WordPress, the editors should not break if it happens.

Step-by-step reproduction instructions

Unregister the taxonomy. For example, copy the following to functions.php in your active theme:

add_action( 'init', 'unregister' );
function unregister() {
	unregister_taxonomy_for_object_type( 'wp_pattern_category', 'wp_block' );
}

Create a new post. Confirm if there is a JavaScript error.

Screenshots, screen recording, code snippet

No response

Environment info

I am using WordPress 6.7 with Gutenberg trunk and:

define( 'WP_DEBUG', true );
define( 'WP_DEVELOPMENT_MODE', 'theme' );
define( 'WP_ENVIRONMENT_TYPE', 'local' );

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

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure

[im3dabasia]

I was able to reproduce the error, and after testing the patch, I can confirm that it resolves the issue.

[carolinan]

I have set this to low priority because I believe that unregistering this taxonomy would be a very uncommon edge case.