Global Styles: Make Button element inherit all typography styles on the frontend

[shrivastavanolo]

What?

Closes #60403

Button elements in WordPress Gutenberg are missing inherited typography styles, including font-style, text-transform, letter-spacing, and font-weight, which are applied in the editor but not on the frontend.

Why?

The issue needs to be fixed because button elements in WordPress Gutenberg are missing some inherited typography styles, including font-style, text-transform, letter-spacing, and font-weight, which are applied in the editor but not on the frontend.

How?

This change is related to an issue where button elements with the wp-element-button class were not inheriting certain typography styles, such as font style, text transform, letter spacing, and font weight, when updated via the Global Styles. The issue was observed when updating typography styles at the root level, then inserting a Search block. The expected behavior is for these styles to be applied to the button element on the frontend, but currently, they are not. The provided code change aims to address this issue by adding the missing styles to the typography object.

Testing Instructions

• Go to the Site Editor > Global Styles > Typography > Text > Typography panel
• Update all styles.
• Insert a Search block in a post and check if it's style is getting inherited on the front end.

Screenshots or screencast

Before

After

---

note: please let me know if this needs to be backported to core, I'll be happy to create a corresponding core ticket for it.

[github-actions]

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Co-authored-by: shrivastavanolo <shreya0shrivastava@git.wordpress.org>
Co-authored-by: t-hamano <wildworks@git.wordpress.org>
Co-authored-by: annezazu <annezazu@git.wordpress.org>

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[github-actions]

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[t-hamano]

@shrivastavanolo Thanks for the PR!

This PR makes sense to me, but this improvement requires a bit more work to get right in both core and Gutenberg. The reason is that this default theme.json file works correctly when the plugin is enabled, but doesn't work when the plugin is disabled. We need to submit a core ticket and a patch so that we can ship this enhancement in the next core release.

First, check the following documentation: https://github.com/WordPress/gutenberg/blob/795734c9741904eb00243bae1f3d787512052e03/backport-changelog/readme.md

Have you ever submitted a ticket or patch to core?

[shrivastavanolo]

Hey, @t-hamano

Have you ever submitted a ticket or patch to core?

Yeah, I have submitted some PRs to wordpress-develop before. I have gone through the documentation you shared and will start by creating a Trac ticket for this and then adding the core PR to the changelog. Thanks for the feedback!

[t-hamano]

Thank you, @shrivastavanolo! Just to be sure, I'll tell you the tasks we need to do.

• Submit a core ticket with the same content as a. It would be a good idea to link #60403 to that core ticket.
• Submit a patch to that core ticket.
• In this PR, create a backport-changelog/6.9/{core-pr-number}.md file.

[shrivastavanolo]

Hey @t-hamano,
I've completed all the mentioned tasks: submitted the core ticket + patch, and added the backport changelog file in this PR. Let me know if anything else is needed. Thanks!

[t-hamano]

LGTM! Everything seems to be working as expected.

Testing Instructions

• Go to the Site Editor > Global Styles > Typography > Text > Typography panel
• Update all typography styles (Font, Font Size, Appearance, Line height, Letter Spacing, Letter Case)
• Create a post.
• To test both the search block and the button element, insert the following HTML via the code editor:

  <!-- wp:search {"label":"Search","placeholder":"Placeholder","buttonText":"Push Me"} /-->
  <!-- wp:html -->
  <button class="wp-element-button">Push Me</button>
  <!-- /wp:html -->

Screenshots

Before

Some typography styles are not being applied to the buttons:

After

All typography styles are applied to both the Search block and the button element: