Crash when saving data using datastore

[amruth-movano]

Describe the bug

We are saving data to data store with predicate. I am getting crash when predicate is not nil. But when predicate set to nil, everything works fine.

Fatal error: SWIFT TASK CONTINUATION MISUSE: save(_:modelSchema:where:) tried to resume its continuation more than once, throwing DataStoreError: Cannot apply a condition on model which does not exist.
Recovery suggestion: Save the model instance without a condition first.!

But we want to add predicate for all the queries

Steps To Reproduce

1. Save the data using predicate

Expected behavior

App should save data to dynamodb

Amplify Framework Version

2.28.0

Amplify Categories

DataStore

Dependency manager

Swift PM

Swift version

5.0

CLI version

NA

Xcode version

15.2

Relevant log output

Fatal error: SWIFT TASK CONTINUATION MISUSE: save(_:modelSchema:where:) tried to resume its continuation more than once, throwing DataStoreError: Cannot apply a condition on model which does not exist.
Recovery suggestion: Save the model instance without a condition first.!

Is this a regression?

No

Regression additional context

No response

Platforms

iOS

OS Version

iOS 17.4

Device

iPhone 15 Plus

Specific to simulators

No response

Additional context

No response

[ruisebas]

Hi @amruth-movano , thanks for opening this issue. We will try to reproduce and post any updates here.

To help us root cause, could you please enable verbose logging by adding Amplify.Logging.logLevel = .verbose before calling Amplify.configure() and share with us the logs up until the crash?

If you can add some code snippets on how you're using the API, that's also helpful.

Thanks!

[amruth-movano]

@ruisebas please see the attached file with verbose output.
amplify_verbose.txt

[amruth-movano]

@ruisebas , We are saving the data directly to dynamodb using datastore.

public final class SampleDataStore: SampleDataStorable {

    private let dataStore: DataStoreBaseBehavior
    private var userId: GetUserId

    init(dataStore: DataStoreBaseBehavior, userId: @escaping GetUserId) {
        self.dataStore = dataStore
        self.userId = userId
    }

    public convenience init() {
        self.init(
            dataStore: Amplify.DataStore,
            userId: { try await Amplify.Auth.getCurrentUser().userId }
        )
    } 
    public func saveSampleData(_ value: DataStore.SampleData) async throws {
        let userId = try await userId()
        let telemetry = SampleDataMapper.map(value, userId: userId)

        _ = try await dataStore.save(telemetry, where: nil)
    }
}

[ruisebas]

Hi @amruth-movano, thank for all the information. I was able to reproduce the crash and I'm working on a fix for it.

However, please note that setting a predicate condition on a create operation (i.e. calling save with a model that does not exist) is not supported and it will result in a failure. You can only set conditions on update operations (i.e. calling save with a model that already exist).

[5d]

The DataStore feature is designed to enable data accessibility even when the device is not connected to the internet or has limited connectivity. When you create model instances using DataStore.save, it does not directly create the item in the DynamoDB table. Instead, it saves the data to a local SQLite database first, and then synchronizes it with the DynamoDB table later.
If you want to apply conditional checks while creating items directly in the DynamoDB table, you can use the API plugin provided by Amplify.

Amplify.API.mutate(.mutation(...))

[5d]

The fix for multiple withCheckedContinuation invocations is released in v2.29.1. This issue is closed for now, but feel free to reopen it if the problem persists.

[github-actions]

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