IssueTracker

Component used: paging

Version used: 3.3.5

Devices/Android versions reproduced on: emulator

Currently returning InitializeAction.LAUNCH_INITIAL_REFRESH from initialize() queues prepend/append calls to fire after the refresh completes. This causes multiple issues:

1. The PagingState for the append/prepend calls may be stale making it unreliable.
2. The prepend/append call may be unnecessary if the refresh no-ops or returns enough items to cover the viewport.

While the documentation covers this behavior it does not explain how to actually handle it. From my investigation I'm not sure if it's even possible. Even the sample RemoteMediator in the docs gets this wrong.

I propose instead the behavior of LAUNCH_INITIAL_REFRESH should:

1. Cancel pending prepend/append calls
2. Wait for the refresh to finish and update the UI
3. Fire prepend/append again if necessary