Error, when slug of font size contains a number

[scrobbleme]

Description

When I create a font size with a number in the slug, i.e.

 [
            'name' => 'Size 1',
            'slug' => 'size1',
            'size' => 10,
 ],
 [
            'name' => 'Size 2',
            'slug' => 'size2size',
            'size' => 20,
 ],

it becomes:

has-size-1-font-size
has-size-2-size-font-size

The expected behavior was

has-size1-font-size
has-size2size-font-size

If this is intended, it is anything else than obvious behavior.

Step-by-step reproduction instructions

Create child theme and add something like:

add_action('after_setup_theme', function () {
    $font_sizes = [
        [
            'name' => 'Size 1',
            'slug' => 'size1',
            'size' => 50,
        ]
    ];

    add_theme_support('editor-font-sizes', $font_sizes);
}, 100);

Screenshots, screen recording, code snippet

No response

Environment info

• Latest WordPress
• With a child theme of Twentytwentyone with the function above as only thing added

Pre-checks

• I have searched the existing issues.
• I have tested with all plugins deactivated except Gutenberg.

[skorasaurus]

Hi,

Thanks for reporting;
This has been already been reported at #31629. Feel free to add your reaction and follow its progress in the issue.