🔌 Silent WebSocket Disconnects

[ghunkins]

Issue

SocketTransport handles disconnects (onError or onDone events) silently by marking itself as not connected. When these disconnects occur, a WalletConnectSession appears to be connected but cannot send or receive messages.

Impact

In release and profile mode, when a user puts the app into the background (i.e. to sign a message in their wallet app), the sockets get closed. On return, the session can't send or receive messages despite it looking connected.

Fix

Re-open the socket when onError and onDone events are fired.

I am opening a PR on this and will link it here.

[bobwith2bees]

This may viable workaround:

  // add to ScreenState  'with WidgetsBindingObserver '
  // https://api.flutter.dev/flutter/widgets/WidgetsBindingObserver-class.html

  @override
  void initState() {
    // Register observer so we can see app lifecycle changes.
    WidgetsBinding.instance!.addObserver(this);
    super.initState();
  }

  /// The wallet connect client, sometimes loses the webSocket connection when the app is suspended
  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    DateFormat dateFormat = DateFormat("HH:mm:ss");
    String dateString = dateFormat.format(DateTime.now());

    logger.d("$dateString AppLifecycleState: ${state.toString()}.");

    if (state == AppLifecycleState.resumed) {
      if (mounted) {
        if (walletConnect.connected && walletConnect.transport.connected == false)) {
          logger.e('$dateString  Wallet connected, but transport is down.  Attempt to recover.');
          walletConnect.transport.open();
        }
      }
    }
  }

  @override
  void dispose() {
    super.dispose();
    // Remove observer for app lifecycle changes.
    WidgetsBinding.instance!.removeObserver(this);
  }

[RootSoft]

The reconnection logic is now improved in v0.0.8.
We will also introduce a Flutter widget to keep the connection alive, based on @bobwith2bees code.

Thanks @bobwith2bees and @ghunkins