IssueTracker

The Paging 3 library (v3.3.4) have unexpected behavior when the app is run for the first time after installation. According to the official documentation, inside LoadtType.APPEND block of load() method:

"If lastItem is null, it means no items were loaded after the initial REFRESH, and there are no more items to load."

Based on this, I used the following logic:

LoadType.APPEND -> {
    // If lastItem is null it means no items were loaded after the initial REFRESH
    // and there are no more items to load.
    val lastItem = state.lastItemOrNull() ?: return MediatorResult.Success(
        endOfPaginationReached = true
    )
    (lastItem.index / state.config.pageSize) + 1
}

Problem:

This logic works as intended in all cases except during the app's first run after installation, it only loads a single page (triggered by LoadType.REFRESH) and incorrectly concludes that there are no more items to load because state.lastItemOrNull() return null (PagingState: first_launch_first_append.png). This results in the app failing to load subsequent pages of data.

Once the app is restarted or the user manually refreshes the page, the behavior works as expected (PagingState: nth_launch_first_append.png)

Steps to Reproduce:

1. Install the app for the first time.
2. Ensure LoadType.REFRESH is triggered.
3. Observe that only the first page of data is loaded, and subsequent pages are not fetched.

Expected Behavior:

• After the initial LoadType.REFRESH, the Paging 3 library should correctly continue loading subsequent pages, even on the app's first run.

Actual Behavior:

• After the initial LoadType.REFRESH, the library incorrectly determines that no more data needs to be loaded.