Previous days posts not loaded in the app

[guarani]

Expected behavior

All users, regardless of their role, should be able to see their own posts in the app's Posts screen (My Site → Blog Posts → Published tab).

Actual behavior

In certain circumstances, authors cannot see their own posts in the app's Posts screen. This appears to happen when other users of the site publish enough posts to "push" the authors posts off the result page. This shouldn't happen, an author is requesting their posts, so the amount of posts published by other users shouldn't influence here.

Screen shown despite author having published posts

Note: Other roles such as contributors may also be affected.

Steps to reproduce the behavior

1. Locate a WP.com site (e.g. a Simple site) and a site user with an author role
2. Ensure the author has published posts (check on WP.com if needed)
3. Publish 40 posts from other users (this is 40 because the app asks for 40 posts from the backend API to populate the Blog Posts screen – we have test accounts with this number of posts published, just ping for access)
4. Log in to the WPiOS app
5. Locate the site and navigate to My Site → Blog Posts → Published tab
6. Notice that no posts are shown

Tested on iPhone 11, iOS 14.7.1, WPiOS 18.0 (18.0.0.1 beta)

_{Internal reference p4a5px-2L9-p2}

This issue mirrors its WPAndroid counterpart wordpress-mobile/WordPress-Android#15213.

[guarani]

Take the following scenario: On a fresh site, an author publishes a post, goes to the post list, and sees their post as expected. Then, other users publish posts – let's say 50 posts are published. Next, the author goes to view their blog posts in the app and finds that their post list is empty. Why?

@twstokes and I investigated this and what we saw was that the API endpoint that the app uses to fetch posts returns paged results, but has the following quirk:

1. In the above scenario, when the author publishes their post and goes to the post list, the app makes a request to the API endpoint requesting a page size of 40 and passing the context=edit query parameter.
2. The API response includes the single post (as expected) and a found attribute with a value of 1
3. Fifty posts are published by other users.
4. The author returns to the post list to view their post
5. The API endpoint now responds with an empty result set (unexpectedly) but will also include a found attribute with a value of 1. What we think this means is that the API found 1 result, but it was not within the requested page size of 40. The reason it was not within the requested page size of 40 may be because the other 50 posts are erroneously taking up all forty "spots" in that result set.

[guarani]

Here's an annotated screenshot showing what happens as more posts a published by other users, "pushing" the author's posts out of the API response result set. Note that WPiOS requests 40 results, hence the significance of the number in the following screenshot.

[dangermattic]

Thanks for reporting! 👍