Merge pull request #103 from lightninglabs/2024-02-fix-lnc-disconnection-error

Fix WASM-client disconnection error

Author: ellemouton

cmd/wasm-client/log.go

@@ -4,6 +4,7 @@ package main
 
 import (
 	"github.com/btcsuite/btclog"
+	"github.com/lightninglabs/lightning-node-connect/gbn"
 	"github.com/lightninglabs/lightning-node-connect/mailbox"
 	"github.com/lightningnetwork/lnd"
 	"github.com/lightningnetwork/lnd/build"
@@ -25,6 +26,7 @@ func SetupLoggers(root *build.RotatingLogWriter, intercept signal.Interceptor) {
 
 	lnd.SetSubLogger(root, Subsystem, log)
 	lnd.AddSubLogger(root, mailbox.Subsystem, intercept, mailbox.UseLogger)
+	lnd.AddSubLogger(root, gbn.Subsystem, intercept, gbn.UseLogger)
 
 	grpclog.SetLoggerV2(NewGrpcLogLogger(root, intercept, "GRPC"))
 }

cmd/wasm-client/main.go

@@ -288,12 +288,29 @@ func (w *wasmClient) IsConnected(_ js.Value, _ []js.Value) interface{} {
 	return js.ValueOf(w.lndConn != nil)
 }
 
-func (w *wasmClient) Disconnect(_ js.Value, _ []js.Value) interface{} {
+// Disconnect disconnects the client, and closes the connection.
+// The first argument passed should be a onDisconnect callback, which will be
+// invoked once the client has disconnected.
+func (w *wasmClient) Disconnect(_ js.Value, args []js.Value) interface{} {
 	if w.lndConn != nil {
-		if err := w.lndConn.Close(); err != nil {
-			log.Errorf("Error closing RPC connection: %v", err)
-		}
-		w.lndConn = nil
+		// We launch the closure of the connection in a goroutine to
+		// avoid that the JS websocket freezes and blocks while closing.
+		go func() {
+			if err := w.lndConn.Close(); err != nil {
+				log.Errorf("Error closing RPC connection: %v",
+					err)
+			}
+			w.lndConn = nil
+
+			// We expect the first arg to be the onDisconnect
+			// callback
+			if len(args) > 0 && args[0].Type() == js.TypeFunction {
+				callback := args[0]
+
+				// Call the onDisconnect callback.
+				callback.Invoke()
+			}
+		}()
 	}
 
 	return nil

example/index.html

@@ -98,8 +98,10 @@
     }
 
     async function disconnect() {
-        window[namespace].wasmClientDisconnect();
+        window[namespace].wasmClientDisconnect(onDisconnect);
+    }
 
+    function onDisconnect() {
         document.getElementById('disconnectBtn').disabled = true;
         document.getElementById('reconnectBtn').disabled = false;
         document.getElementById('ready').style.display= 'none' ;