Reader Recent Feed: Fix flash of onboarding when loading

[allilevine]

Related to #96988

Proposed Changes

• When the feed is loading there's sometimes a flash of onboarding, and the onboarding viewed Tracks event is being fired incorrectly. I realized I need to check for siteSubscriptions?.subscriptions.length, not just the existence of siteSubscriptions?.subscriptions. Otherwise we can have subscriptionsCount greater than 0, but no actual subscriptions to check.

Before:

Screen.Recording.2024-12-05.at.11.28.01.AM.mov

After:

Screen.Recording.2024-12-05.at.11.27.17.AM.mov

Why are these changes being made?

• Improve the UX and the accuracy of the Tracks event.

Testing Instructions

• Load or reload /read
• If you have subscriptions to sites that aren't your own, you should not see a flash of onboarding and calypso_reader_onboarding_viewed should not be fired.
• Otherwise, you should see onboarding and calypso_reader_onboarding_viewed should be sent to Tracks.

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 UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• 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-aUh-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-126647

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-126647&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-126647&env=a8c-for-agencies

[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

Generated by performance advisor bot at iscalypsofastyet.com.

[matticbot]

This PR modifies the release build for the following Calypso Apps:

For info about this notification, see here: PCYsg-OT6-p2

• notifications
• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug fix/reader-recent-feed-onboarding-showing on your sandbox.