Scanner throws exception from advertisements Flow on premature closure

[twyatt]

Issue/question raised on StackOverflow.

I believe the issue is with Kable's internals not properly handling the premature closure in the callbackFlow.

As per the callbackFlow KDoc, we should be catching exceptions when trying to emit within the callbackFlow (emphasis shown in green):

  fun flowFrom(api: CallbackBasedApi): Flow<T> = callbackFlow {
      val callback = object : Callback { // Implementation of some callback interface
          override fun onNextValue(value: T) {
              // To avoid blocking you can configure channel capacity using
              // either buffer(Channel.CONFLATED) or buffer(Channel.UNLIMITED) to avoid overfill
+             try {
                  sendBlocking(value)
+             } catch (e: Exception) {
+                 // Handle exception from the channel: failure in flow or premature closing
+             }
          }
          override fun onApiError(cause: Throwable) {
              cancel(CancellationException("API Error", cause))
          }
          override fun onCompleted() = channel.close()
      }
      api.register(callback)
      /*
       * Suspends until either 'onCompleted'/'onApiError' from the callback is invoked
       * or flow collector is cancelled (e.g. by 'take(1)' or because a collector's coroutine was cancelled).
       * In both cases, callback will be properly unregistered.
       */
          awaitClose { api.unregister(callback) }
      }

[twyatt]

Fix can be tried/tested via:

import java.net.URI

repositories {
    maven { url = URI("https://oss.sonatype.org/content/repositories/snapshots") }
}

dependencies {
    implementation("com.juul.kable:core:0.2.0-issue-67-SNAPSHOT")
}

---

SNAPSHOT published from #68.