Context

• Convert the How To block and the FAQ block to the Blocks V3 API #21329 introduced a limitation of 1 FAQ block per post by mistake, and removed a class from the resulting output for the FAQ and the How To block.

Summary

This PR can be summarized in the following changelog entry:

• Fixes a bug preventing multiple FAQ blocks from being added to a post/page.
• Fixes a bug where a class was missing in the output of the FAQ and How-To blocks.

Relevant technical choices:

Test instructions

Test instructions for the acceptance test before the PR gets merged

This PR can be acceptance tested by following these steps:

• Important: test using an artifact instead of just building from the source, since there is an integral part of this PR that is related to copying the blocks JSON to a dist dir and finding it there.

1. Multiple FAQ blocks

New blocks

• create a post and add two or more FAQ blocks
  • add some questions and answers
  • publish it and check the Schema: the page should be a FAQPage with mainEntity set to all the Question pieces from all the FAQ blocks combined

Upgrading

• on another site, install Free 22.6
• create a post and add two or more FAQ blocks
• add some questions and answers and publish
  * if you now upgrade to 22.7 and edit the post you'll see a warning telling you that you cannot use the block twice.
• upgrade to the zip containing this fix
• edit the post and see that there is no warning now
• inspect the Schema and check it's right
• edit the FAQ blocks again and verify everything's working

2. Block markup

New blocks

• create a post and add a FAQ block and a How To block, with some content
• publish it and inspect the source of the page in the frontend
• check that the FAQ block is outputted as <div class="schema-faq wp-block-yoast-faq-block"> and the How-to block as <div class="schema-how-to wp-block-yoast-how-to-block">

Upgrading from 22.6 or earlier

• on another site, install Free 22.6
• create a post and add a FAQ block and a How To block, with some content
• publish it
• upgrade to this version
• edit the post and see that you don't get any warning
• apply a small change somewhere in the content and save
• check that the FAQ block is outputted as <div class="schema-faq wp-block-yoast-faq-block"> and the How-to block as <div class="schema-how-to wp-block-yoast-how-to-block">

Upgrading from 22.6 or earlier

• on another site, install Free 22.7
• create a post and add a FAQ block and a How To block, with some content
• publish it
• upgrade to this version
• edit the post and see that you get warning like these ones:
  
• click on the "Attempt recovery" buttons and see they are restored
• update the post and inspect the frontend
• check that the FAQ block is outputted as <div class="schema-faq wp-block-yoast-faq-block"> and the How-to block as <div class="schema-how-to wp-block-yoast-how-to-block">

Relevant test scenarios

• Changes should be tested with the browser console open
• Changes should be tested on different posts/pages/taxonomies/custom post types/custom taxonomies
• Changes should be tested on different editors (Default Block/Gutenberg/Classic/Elementor/other)
• Changes should be tested on different browsers
• Changes should be tested on multisite

Test instructions for QA when the code is in the RC

• QA should use the same steps as above.

QA can test this PR by following these steps:

Impact check

This PR affects the following parts of the plugin, which may require extra testing:

UI changes

• This PR changes the UI in the plugin. I have added the 'UI change' label to this PR.

Other environments

• This PR also affects Shopify. I have added a changelog entry starting with [shopify-seo], added test instructions for Shopify and attached the Shopify label to this PR.

Documentation

• I have written documentation for this change. For example, comments in the Relevant technical choices, comments in the code, documentation on Confluence / shared Google Drive / Yoast developer portal, or other.

Quality assurance

• I have tested this code to the best of my abilities.
• During testing, I had activated all plugins that Yoast SEO provides integrations for.
• I have added unit tests to verify the code works as intended.
• If any part of the code is behind a feature flag, my test instructions also cover cases where the feature flag is switched off.
• I have written this PR in accordance with my team's definition of done.
• I have checked that the base branch is correctly set.

Innovation

• No innovation project is applicable for this PR.
• This PR falls under an innovation project. I have attached the innovation label.
• I have added my hours to the WBSO document.

Fixes #21401
Fixes #21403