Error in restarting subscription after cancellation

[Laxmikantwagh]

Describe the bug
When app goes to background , we cancel the subscription. Next time, when app moves to foreground, we restart subscription. But sometimes, when app comes to foreground/ active state, the request of restarting subscription does not work. At this time, there is no error callbacks.

To Reproduce
Steps to reproduce the behavior:

1. Launch the app (subscription is activated as app is in active state).
2. Now, lock the device and then unlock it.
3. Step 2 should be repeated 3-4 times quickly.
4. Unlock the device.
5. Now, the subscription never starts.

Expected behavior
If app is moved to background and foreground multiple times and then if app is in foreground/active state finally, the request to restart subscription should be successful.

Environment

• AppSync SDK Version: 2.10.3
• Dependency Manager: Cocoapods
• Swift Version : 4.2

Device Information:

• Device: iPhone 6, iPhone X
• iOS Version: 12.2

More Information
We have just tried one thing.
class -> AWSAppSyncSubscriptionWatcher.swift
method -> init

In this method, self.startSubscription() was not being called sometimes. So, we have updated this method.

PFA screen shot for more details.

Conclusion:
Please suggest on this bug.
Also, please check our approach. Do you have any better way to fix this issue ?

[shannon-hager-skookum]

@Laxmikantwagh The AppSync SDK version listed above is 2.10.3, I would update to the current version (2.12.1) and see if the problem is still present. There has been some work on this area of functionality that would may solve your issue and if not, might affect your workaround.

[palpatim]

This is released on https://github.com/awslabs/aws-mobile-appsync-sdk-ios/releases/tag/2.12.2

Please let us know if you have any further issues.

[Laxmikantwagh]

Thank you so much 👍 . I will check it and get back if required.