ConflatedBroadcastChannel losing most recent Event

[ScottPierce]

I'm using kotlinx.coroutines version 1.1.1, and Kotlin 1.3.20.

I'm using a ConflatedBroadcastChannel to send View events in Android (from the main thread) to the presenter that that receives them (also on the main thread).

The documentation for ConflatedBroadcastChannel says:

only the the most recently sent value is received, while previously sent elements are lost.

In this case, the reverse is actually true. The most recent value is lost, while previously sent values make it through.

Relevant View code:

val broadcastChannel: BroadcastChannel<AuthEmailEvent> = ConflatedBroadcastChannel()

val selectedCredential = state.previousCredentials[position]
broadcastChannel.offer(AuthEmailEvent.EmailUpdate(selectedCredential.first))
broadcastChannel.offer(AuthEmailEvent.PasswordUpdate(selectedCredential.second))

actual fun events(): ReceiveChannel<AuthEmailEvent> = broadcastChannel.openSubscription()

Relevant Presenter code:

for (event in view.events()) {
  when (event) {
    is AuthEmailEvent.EmailUpdate -> state = state.copy(
      email = event.email,
      isEmailValid = !event.email.isBlank()
    )
    is AuthEmailEvent.PasswordUpdate -> state = state.copy(
      password = event.password,
      isPasswordValid = !event.password.isBlank()
    )
  }
}

The first event, AuthEmailEvent.EmailUpdate is received and processed, but the AuthEmailEvent.PasswordUpdate, which is the most recent event is lost, and never received.

[ScottPierce]

After further debugging, I realized that the first event triggers more offered events. That's what's causing the Password event to be lost.

I've instead expressed my support for an Unlimited BroadcastChannel:
#736 (comment)