Since this theme depends on full-site editing, it doesn't seem like there will be anything in the theme itself which is not AMP-compatible, as it is comprised of blocks coming from core. Therefore it's likely the majority or the work here will be to ensure that FSE is AMP-compatible.

For example: #6115 and #6319.

So the good thing here is that if we can ensure AMP is FSE-compatible, then any such theme will just work.

QA Not Passed

✅ Ensure sure the Twenty-Two theme is AMP compatible

I've browsed a site based on WordPress 5.9 with Twenty-Two theme activated and everything seemed to be working as expected, including items like site navigation (navigation block), adding comments, and search.

There were no AMP validation errors reported.

🚫 Add the theme as a Reader theme option

Twenty-Two is not among Reader themes:

If the only fail is the theme not being listed among the Reader themes, then great. We can easily add it. We'll just need a mobile screenshot to add to https://github.com/ampproject/amp-wp/tree/develop/assets/images/reader-themes

If the only fail is the theme not being listed among the Reader themes, then great. We can easily add it. We'll just need a mobile screenshot to add to https://github.com/ampproject/amp-wp/tree/develop/assets/images/reader-themes

Thanks for the hint. I've added a Twenty Twenty-Two thumbnail to the repo and added its slug to the list of supported Reader Themes in #6870.

One unexpected thing I noticed is that the "Edit site" menu item is rendered in WP admin bar when TT2 is set as a Reader Theme:

After clicking on the link, I get an error like:

I think that there might be more of such little things here and there WordPress 5.9 and TT2 introduced quite a bit of changes.

After clicking on the link, I get an error like:

Do you get the same issue when the AMP plugin is deactivated?

Do you get the same issue when the AMP plugin is deactivated?

No, when I select TT2 as a regular theme in Standard or Transitional mode (not as a Reader Theme), the link leads to the new site editor. In the same way, if AMP is completely deactivated, the link works as expected.

So this is only the case if TT2 is set as a Reader Theme. I guess we should probably remove this link from the admin bar if in Reader Mode. What do you think?

So this is only the case if TT2 is set as a Reader Theme. I guess we should probably remove this link from the admin bar if in Reader Mode. What do you think?

Oh yes, you're right. Humm, in that case I think we'll need to wait on adding TT2 to the list of Reader themes as we'll need to make the Site Editor accessible with the Reader theme active, in the same way we load the Reader theme when loading the AMP Customizer. Otherwise the user wouldn't be able to edit the AMP pages. It may end up being that the Site Editor can't be forced to load the Reader theme, but we'll need to do more research in that area. So I'll move the milestone to 2.3 for now. Thanks for identifying this!

This is done.