Jetpack button: prevent button from stretching vertically

[monsieur-z]

Fixes #40851

Proposed changes:

A user reported an issue with the height of the Jetpack button in a Mailchimp block. The button would stretch vertically. We could link the root of the issue to this Gutenberg update, which applied a height: 100% rule to the button .wp-block-button__link element. To counterbalance that, we're explicitly marking the height of .wp-block-button as fit-content.

Before	After

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

n/a

Does this pull request change what data or activity we track or use?

No.

Testing instructions:

No one who tried to troubleshoot this issue could reproduce the bug locally or in a new environment (see the issue comment thread). To verify that this fix works, we can manually edit the CSS on the user site.

• Visit https://berkhistory.org/sign-up-for-email/
• Open the dev tool and inspect the Mailchimp submit button (see capture above)
• On the .wp-block-button__link element, comment out the height: unset rules that were manually added as a fix

• The button should stretch vertically (see capture above)
• On .wp-block-button, apply the rule height: fit-content. The button should no longer stretch.

[github-actions]

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Jetpack plugin:

The Jetpack plugin has different release cadences depending on the platform:

• WordPress.com Simple releases happen semi-continuously (PCYsg-Jjm-p2).
• WoA releases happen weekly.
• Releases to self-hosted sites happen monthly. The next release is scheduled for none scheduled (scheduled code freeze on undefined).

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[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WordPress.com Simple site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin, and enable the fix/jetpack-button-height branch.

• To test on Simple, run the following command on your sandbox:

  bin/jetpack-downloader test jetpack fix/jetpack-button-height
  

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[github-actions]

Code Coverage Summary

This PR did not change code coverage!

That could be good or bad, depending on the situation. Everything covered before, and still is? Great! Nothing was covered before? Not so great. 🤷

Full summary · PHP report · JS report

[coder-karen]

Tests well on the affected site applying manually, and testing on my own test sites the Mailchimp (and all) buttons that work well are not affected.