Testing
You need to test the following scenarios under Cloud Services.
Once after re-installing the app, the data needs to be retained post first sync
Data should exist on other devices for the same account once a synchronize is successful
Cloud Services testing needs to be performed on real mobile hardware device
Testing data post re-install
Call Synchronize for the first time of launch and it prompts a login if required to connect user profile.
Set a key value and note the details
Wait for synchronize or call Synchronize manually
Uninstall the app
Install the app again
Call Synchronize
Get the key value set in step 2
Check data in step 2 and step 7 and they should match.
Data existence on other devices
Call Synchronize for the first time of launch and it prompts a login if required to connect user profile.
Set a key value and note the details
Wait for synchronize or call Synchronize manually
Jump to another device with same user account (iCloud on iOS, Google Play on Android)
Call Synchronize
Get the value for key set in step 2
Check data in step 2 and step 7 and they should match.
On Android, we always consider the data copy which has the longest play time for conflict resolution in case of any conflicts.
Make sure while testing, you use same user account on testing devices. As the feature relies internally on iCloud and Google play services, for sync it needs common account which is quite expected.