Reading Settings: Add 'Your homepage displays' site setting

[mashikag]

Proposed Changes

• Add Your homepage displays setting to the new Reading Settings page

  • Display it at the top of the Site settings section

  • Use the GET /sites/$site/dropdown-pages/ endpoint to populate the setting's dropdown options

  • A page selected in one of the dropdowns should be disabled in another dropdown. E.g.: I have selected About page for Your homepage displays dropdown. Then once I open up the Default posts page dropdown the About page should be disabled.

  • Display an explanation note as:

    Default homepage and posts page content and layout are determined by your active theme. Learn More.

    For now the "Learn more." link leads to https://wordpress.com/support/templates but there is a new support doc being written up that will replace it when the feature goes out to prod. The following ticket tracks the doc work: https://github.com/Automattic/en.support-docs-content/issues/1805

Testing Instructions

‼️ Be aware that unsetting the Default posts page does not work properly with the component for now due to the following backend issue: #72119

• Apply jetpack's trunk to your sandbox
• Sandbox public-api.wordpress.com
• Go to http://calypso.localhost:3000/settings/reading/$site, e.g.: http://calypso.localhost:3000/settings/reading/simple-site.blog

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-ajp-p2)?

Fixes #70409

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-54118

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-54118&env=jetpack

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~799 bytes added 📈 [gzipped])

name              parsed_size           gzip_size
settings-reading      +3065 B  (+1.1%)     +799 B  (+0.9%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[ivan-ottinger]

The PR works as expected and the proposed changes look good to me. 👍🏼👍🏼

I am going to continue reviewing and testing the PR (also on other kinds of sites - not just Simple) once I am back from lunch and wanted to share the initial notes earlier:

• I did not notice any JS, React or TS errors nor warnings.
• The strings for translation look good.
• There's one smaller issue with the usage of concat() method (please see the comment in the code below) - current output can be seen in the screenshot below as well - where the em dashes are not separated from the page title.
• The page that is selected for the Home page gets disabled properly:

And thank you for ordering multiple elements (typed objects, returned object's properties, etc...) in alphabetical order. 🙂

[ivan-ottinger]

Tested again after the latest changes. Everything is working as expected. 🙂👍🏼

Page title is now properly separated from dash with a space (for child pages):

Drop-downs display correctly on smaller screens.

Similarly as with other related PR, we were not able to test with Atomic, not Jetpack-connected sites - as /sites/%s/dropdown-pages/ endpoint is not available for them yet.

[a8ci18n]

This Pull Request is now available for translation here: https://translate.wordpress.com/deliverables/7738377

Thank you @mashikag for including a screenshot in the description! This is really helpful for our translators.

[a8ci18n]

Translation for this Pull Request has now been finished.