Classic Theme Helper: Adding in Responsive Video class initialization from the Jetpack Mu WPcom package

[coder-karen]

Fixes https://github.com/Automattic/vulcan/issues/386

Proposed changes:

• This PR adds back the Classic Theme Helper package Main class initialization from the Jetpack Mu WPcom package, as it was initially added in this PR - Classic Theme Helper: Requiring the Responsive Video package files, and modifying Featured Content require process #37969 - and then removed as it's addition would cause fatal errors (functions in the module file being redeclared) if wpcomsh was updated before Jetpack.

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

https://github.com/Automattic/vulcan/issues/386

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

No.

Testing instructions:

• For this we're primarily testing on Simple and WoA. Since Jetpack is now updated on WoA and Simple sites, we're basically testing with the current Jetpack version and with this PR checked out (using the script in the comment below on Simple, and with this PR applied using the Beta Tester plugin on a WoA site, for the WPcom Features plugin).
• Once the environment is set up, follow the remaining testing instructions here but just for Responsive Videos: Classic Theme Helper: Requiring the Responsive Video package files, and modifying Featured Content require process #37969
• The script in the page source on WoA sites - jetpack-responsive-videos-js - should be via the jetpack-mu-wpcom plugin. Without this PR applied it is the same, and this is because of the new class_exists check via the Jetpack module file, which actually ends up running the class file (which has an initialization call) via the Classic Theme Helper package. This will be removed in a later version.
• The script in the page source on Simple sites - jetpack-responsive-videos-js - should also be via jetpack-mu-wpcom plugin. Without this PR applied it should be via the responsive-videos.js script (no ID) if testing whilst not sandboxed, but still jetpack-responsive-videos-js if sandboxed without the changes applied (also via the jetpack-mu-wpcom plugin, but this is also because of the new class_exists check via the Jetpack module file).
• Make sure there are no errors reported - on Simple tail -f /tmp/php-errors, on WoA in the debug.log.

[github-actions]

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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 add/classic-theme-helper-package-initialization branch.

  • For jetpack-mu-wpcom changes, also add define( 'JETPACK_MU_WPCOM_LOAD_VIA_BETA_PLUGIN', true ); to your wp-config.php file.

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

  bin/jetpack-downloader test jetpack-mu-wpcom-plugin add/classic-theme-helper-package-initialization
  

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

[darssen]

This tests well.

A side note for the future is that I was not able to reproduce below instructions while not sandboxed since my simple site was not showing the responsive-videos.js scrip as expected. Other simple sites were showing it, and it's not related to this PR though.

Without this PR applied it should be via the responsive-videos.js script (no ID) if testing whilst not sandboxed,