setCallbacksForTesting method

@visibleForTesting void setCallbacksForTesting({ required void onMessage(PushMessage), required void onMessageOpenedApp(PushMessage), })

Sets up message callbacks directly, bypassing Firebase SDK calls.

Use this in unit tests to exercise callback behaviour without requiring a real Firebase project or native platform bridges.

Implementation

@visibleForTesting
void setCallbacksForTesting({
  required void Function(PushMessage) onMessage,
  required void Function(PushMessage) onMessageOpenedApp,
}) {
  _onMessage = onMessage;
  _onMessageOpenedApp = onMessageOpenedApp;
  _initialized = true;
}