DataStore - Add OutboxMutationFailed Hub Event Type

[Equartey]

Is your feature request related to a problem? Please describe.

aws-amplify/amplify-flutter#3452

Amplify-Android supports a DataStore hub event called OutboxMutationFailed.

This event is described as:

Dispatched when publishing a mutation fails

HubPayload outboxMutationFailed contains:

• modelName (String): the name of the model that failed to publish
• element:
  - model (Model): the model instance that failed to publish
  - errorType (MutationErrorType): error type that occurred
  - operation (MutationType): type of mutation that failed

Amplify Flutter users would like to have feature parity between Amplify-Swift and Amplify-Android to ensure consistency between error handling on the respective platform.

Describe the solution you'd like

Amplify-Swift should support OutboxMutationFailed event type and send when appropriate.

Describe alternatives you've considered

N/A

Is the feature request related to any of the existing Amplify categories?

DataStore

Additional context

No response

[github-actions]

This has been identified as a feature request. If this feature is important to you, we strongly encourage you to give a 👍 reaction on the request. This helps us prioritize new features most important to you. Thank you!

[stevegaunt]

@Equartey
given this has now quite a few thumbs up, is this likely to be a high priority feature now?

[stevegaunt]

@Equartey
this is quite a useful feature, and does impact us with production data not always getting synced, and then ultimately data loss for the user..

[lawmicha]

Hi @stevegaunt, we recommend using the errorHandler callback to receive errors for when a mutation event fails to sync to AppSync. I can see here https://github.com/aws-amplify/amplify-swift/blob/v1/AmplifyPlugins/DataStore/AWSDataStoreCategoryPlugin/Sync/MutationSync/OutgoingMutationQueue/ProcessMutationErrorFromCloudOperation.swift#L69 DataStore calls the errorHandler with the MutationEvent which has similar information as the outboxMutationFailed above.

MutationEvent: https://github.com/aws-amplify/amplify-swift/blob/v1/Amplify/Categories/DataStore/Subscribe/MutationEvent.swift

You should be able to achieve the same use case by checking the DataStoreError is .api and the associated mutationEvent information. Does this work for you?