Unable to register format type to handle bare tag name

[davilera]

Description

Users are unable to register a new format type to handle a bare tag name (i.e. when className is set to null), as registerFormatType logs the following error:

Format "core/unknown" is already registered to handle bare tag name "xxx".

This occurs because registerFormatType has the following validation snippet in line 80:

if ( settings.className === null ) {
  const formatTypeForBareElement = select(
    richTextStore
 ).getFormatTypeForBareElement( settings.tagName );

  if ( formatTypeForBareElement ) {
    window.console.error(
      `Format "${ formatTypeForBareElement.name }" is already registered to handle bare tag name "${ settings.tagName }".`
    );
    return;
 }
}

that checks if the given tagName is already registered. The current implementation of getFormatTypeForBareElement:

export function getFormatTypeForBareElement( state, bareElementTagName ) {
  const formatTypes = getFormatTypes( state );
  return (
    formatTypes.find( ( { className, tagName } ) => {
      return className === null && bareElementTagName === tagName;
    } ) ||
    formatTypes.find( ( { className, tagName } ) => {
      return className === null && '*' === tagName;
    } )
  );
}

always returns a valid format type for any bare element, because of the second part of the return statement, thus making it impossible to register new formats.

Possible Solution

In registerFormatType, change line 85 from:

if ( formatTypeForBareElement ) {

to

if (
  formatTypeForBareElement &&
  formatTypeForBareElement.name !== 'core/unknown'
) {

Step-by-step reproduction instructions

1. Go to the post editor
2. Open your browser's developer tools
3. In the JavaScript console, type the following:

wp.richText.registerFormatType( 'name/format', {
  title: 'Test bare tag format',
  tagName: 'xxx',
  className: null,
  edit: () => null,
} );

Screenshots, screen recording, code snippet

No response

Environment info

• WordPress 6.1.1
• Gutenberg 14.8.1

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

[t-hamano]

Thanks for the report.
I think this issue is the same as #46777.

[kathrynwp]

I'm going to go ahead and close this out, so that efforts to fix the issue can be concentrated over in the other ticket. Thank you again for reporting!