Merge pull request #4215 from superDingda/bugfix/4211_long_ws_msg_truncation

fix: prevent truncation of long WebSocket messages in dev mode

v2/go.mod

@@ -15,6 +15,7 @@ require (
 	github.com/godbus/dbus/v5 v5.1.0
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
 	github.com/google/uuid v1.6.0
+	github.com/gorilla/websocket v1.5.3
 	github.com/jackmordaunt/icns v1.0.0
 	github.com/jaypipes/ghw v0.13.0
 	github.com/labstack/echo/v4 v4.13.3

v2/go.sum

@@ -107,6 +107,8 @@ github.com/gookit/color v1.5.4 h1:FZmqs7XOyGgCAxmWyPslpiok1k05wmY3SJTytgvYFs0=
 github.com/gookit/color v1.5.4/go.mod h1:pZJOeOS8DM43rXbp4AZo1n9zCU2qjpcRko0b6/QJi9w=
 github.com/gorilla/css v1.0.1 h1:ntNaBIghp6JmvWnxbZKANoLyuXTPZ4cAMlo6RyhlbO8=
 github.com/gorilla/css v1.0.1/go.mod h1:BvnYkspnSzMmwRK+b8/xgNPLiIuNZr6vbZBTPQ2A3b0=
+github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
+github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
 github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
 github.com/itchyny/gojq v0.12.13 h1:IxyYlHYIlspQHHTE0f3cJF0NKDMfajxViuhBLnHd/QU=

v2/internal/frontend/devserver/devserver.go

@@ -20,17 +20,23 @@ import (
 
 	"github.com/wailsapp/wails/v2/internal/frontend/runtime"
 
+	"github.com/gorilla/websocket"
 	"github.com/labstack/echo/v4"
 	"github.com/wailsapp/wails/v2/internal/binding"
 	"github.com/wailsapp/wails/v2/internal/frontend"
 	"github.com/wailsapp/wails/v2/internal/logger"
 	"github.com/wailsapp/wails/v2/internal/menumanager"
 	"github.com/wailsapp/wails/v2/pkg/options"
-	"golang.org/x/net/websocket"
 )
 
 type Screen = frontend.Screen
 
+var upgrader = websocket.Upgrader{
+	ReadBufferSize:  1024,
+	WriteBufferSize: 1024,
+	CheckOrigin:     func(r *http.Request) bool { return true },
+}
+
 type DevWebServer struct {
 	server           *echo.Echo
 	ctx              context.Context
@@ -155,51 +161,64 @@ func (d *DevWebServer) handleReloadApp(c echo.Context) error {
 }
 
 func (d *DevWebServer) handleIPCWebSocket(c echo.Context) error {
-	websocket.Handler(func(c *websocket.Conn) {
-		d.LogDebug(fmt.Sprintf("Websocket client %p connected", c))
+	conn, err := upgrader.Upgrade(c.Response(), c.Request(), nil)
+	if err != nil {
+		d.logger.Error("WebSocket upgrade failed %v", err)
+		return err
+	}
+	d.LogDebug(fmt.Sprintf("WebSocket client %p connected", conn))
+
+	d.socketMutex.Lock()
+	d.websocketClients[conn] = &sync.Mutex{}
+	locker := d.websocketClients[conn]
+	d.socketMutex.Unlock()
+
+	var wg sync.WaitGroup
+
+	defer func() {
+		wg.Wait()
 		d.socketMutex.Lock()
-		d.websocketClients[c] = &sync.Mutex{}
-		locker := d.websocketClients[c]
+		delete(d.websocketClients, conn)
 		d.socketMutex.Unlock()
+		d.LogDebug(fmt.Sprintf("WebSocket client %p disconnected", conn))
+		conn.Close()
+	}()
 
-		defer func() {
-			d.socketMutex.Lock()
-			delete(d.websocketClients, c)
-			d.socketMutex.Unlock()
-			d.LogDebug(fmt.Sprintf("Websocket client %p disconnected", c))
-		}()
+	for {
+		_, msgBytes, err := conn.ReadMessage()
+		if err != nil {
+			break
+		}
 
-		var msg string
-		defer c.Close()
-		for {
-			if err := websocket.Message.Receive(c, &msg); err != nil {
-				break
-			}
-			// We do not support drag in browsers
-			if msg == "drag" {
-				continue
+		msg := string(msgBytes)
+		wg.Add(1)
+
+		go func(m string) {
+			defer wg.Done()
+
+			if m == "drag" {
+				return
 			}
 
-			// Notify the other browsers of "EventEmit"
-			if len(msg) > 2 && strings.HasPrefix(string(msg), "EE") {
-				d.notifyExcludingSender([]byte(msg), c)
+			if len(m) > 2 && strings.HasPrefix(m, "EE") {
+				d.notifyExcludingSender([]byte(m), conn)
 			}
 
-			// Send the message to dispatch to the frontend
-			result, err := d.dispatcher.ProcessMessage(string(msg), d)
+			result, err := d.dispatcher.ProcessMessage(m, d)
 			if err != nil {
 				d.logger.Error(err.Error())
 			}
+
 			if result != "" {
 				locker.Lock()
-				if err = websocket.Message.Send(c, result); err != nil {
-					locker.Unlock()
-					break
+				defer locker.Unlock()
+				if err := conn.WriteMessage(websocket.TextMessage, []byte(result)); err != nil {
+					d.logger.Error("Websocket write message failed %v", err)
 				}
-				locker.Unlock()
 			}
-		}
-	}).ServeHTTP(c.Response(), c.Request())
+		}(msg)
+	}
+
 	return nil
 }
 
@@ -222,7 +241,7 @@ func (d *DevWebServer) broadcast(message string) {
 				return
 			}
 			locker.Lock()
-			err := websocket.Message.Send(client, message)
+			err := client.WriteMessage(websocket.TextMessage, []byte(message))
 			if err != nil {
 				locker.Unlock()
 				d.logger.Error(err.Error())
@@ -256,7 +275,7 @@ func (d *DevWebServer) broadcastExcludingSender(message string, sender *websocke
 				return
 			}
 			locker.Lock()
-			err := websocket.Message.Send(client, message)
+			err := client.WriteMessage(websocket.TextMessage, []byte(message))
 			if err != nil {
 				locker.Unlock()
 				d.logger.Error(err.Error())

website/src/pages/changelog.mdx

@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed window restoration behavior after minimization by @superDingda in [#4109](https://github.com/wailsapp/wails/issues/4109)
 - Fixed excessive console logging after updating to v2.10.1 by @superDingda in [#4111](https://github.com/wailsapp/wails/issues/4111)
 - Fixed incorrect Webview2 reg key in HKCU path by @leaanthony.
+- Fixed long WebSocket messages being truncated in `wails dev` by @superDingda in [#4211](https://github.com/wailsapp/wails/issues/4211)
 
 ## v2.10.1 - 2025-02-24