chore(datastore): Enable cloud sync in integration tests

[HuiSF]

Issue #, if available:

Description of changes:

• Forward native subscritpionDataProcessed (Android) and syncReceived (iOS) events to Dart DataStore hub event stream, these two events are named as subscriptionDataProcessed in dart implementation
• Updated test suites to run with cloud sync
• Split 23 testing models into smaller groups, and run flutter test separately to avoid long subscription and initial sync time which made tests run unstable in Android.

NOTE: Android integration tests stability depends on PR #1339 ...
NOTE2: Cloud sync is enabled for model relationship tests and basic model operation within this PR. More tests with cloud sync will be add separately.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[dnys1]

There is a lot of duplicated code in the tests - is there anyway to DRY this up a bit?

[ragingsquirrel3]

Nice job with this integ test change. It seems pretty stable for me running locally. There might be some challenges with this in CI, but not in scope for this PR IMO. A few high-level callouts:

1. Do we want the subscription events to be separate PR? If not, please reflect both changes in commit message when merged to it's there for anyone who is debugging/bisecting commits.
2. Like Dillon said, would be nice to DRY up the testing logic, left a suggestion for that, but feel free to chat offline more.
3. Test script should return non-zero status if anything fails.
4. Mostly nits after that.

[ragingsquirrel3]

nice!

[HuiSF]

1. Do we want the subscription events to be separate PR? If not, please reflect both changes in commit message when merged to it's there for anyone who is debugging/bisecting commits.

Could to a merge instead of squash merge on this PR (I'll squash comment resolving commits before merge).

[codecov-commenter]

Codecov Report

Merging #1351 (c5d7078) into main (1b5af9d) will decrease coverage by 0.06%.
The diff coverage is 70.00%.

@@            Coverage Diff             @@
##             main    #1351      +/-   ##
==========================================
- Coverage   46.19%   46.12%   -0.07%     
==========================================
  Files         256      257       +1     
  Lines       10086    10089       +3     
==========================================
- Hits         4659     4654       -5     
- Misses       5427     5435       +8     

Flag	Coverage Δ
android-unit-tests	∅ <ø> (∅)
flutter-unit-tests	36.62% <68.96%> (-0.08%)	⬇️
ios-unit-tests	85.36% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...mplify_datastore/lib/method_channel_datastore.dart	67.66% <ø> (ø)
...n_interface/lib/src/types/hub/HubEventElement.dart	0.00% <0.00%> (ø)
...lib/src/types/hub/HubEventElementWithMetadata.dart	0.00% <ø> (ø)
.../src/types/hub/SubscriptionDataProcessedEvent.dart	0.00% <0.00%> (ø)
...store/lib/amplify_datastore_stream_controller.dart	85.00% <80.00%> (-12.50%)	⬇️
...it_tests/DataStoreHubEventStreamHandlerTests.swift	98.58% <100.00%> (ø)

[ragingsquirrel3]

I think the datastore provision script needs a little fix to work with cloud sync, at https://github.com/aws-amplify/amplify-flutter/blob/main/packages/amplify_datastore/example/tool/add_api_request.json#L11 add:

    "conflictResolution": {
      "defaultResolutionStrategy": {
        "type": "AUTOMERGE"
      }
    }

[ragingsquirrel3]

A few small fixes needed and a nit, otherwise looks great! This improved so much, thanks for chipping away at a big, complicated problem and leaving us with this great script.

💯

[dnys1]

Approved, contingent on changes mentioned