fix(socket-handler): Fix socket handler race condition by differentiating between async and sync handlers. Now, async socket handlers complete their setup before initial data is emitted, ensuring that no data is lost. Documentation and tests have been updated to reflect this change.

ts/proxies/smart-proxy/utils/route-helpers.ts

@@ -19,6 +19,7 @@
  * - NFTables routes (createNfTablesRoute, createNfTablesTerminateRoute)
  */
 
+import * as plugins from '../../../plugins.js';
 import type { IRouteConfig, IRouteMatch, IRouteAction, IRouteTarget, TPortRange, IRouteContext } from '../models/route-types.js';
 
 /**
@@ -810,4 +811,99 @@ export function createCompleteNfTablesHttpsServer(
   );
   
   return [httpsRoute, httpRedirectRoute];
-}
+}
+
+/**
+ * Create a socket handler route configuration
+ * @param domains Domain(s) to match
+ * @param ports Port(s) to listen on
+ * @param handler Socket handler function
+ * @param options Additional route options
+ * @returns Route configuration object
+ */
+export function createSocketHandlerRoute(
+  domains: string | string[],
+  ports: TPortRange,
+  handler: (socket: plugins.net.Socket) => void | Promise<void>,
+  options: {
+    name?: string;
+    priority?: number;
+    path?: string;
+  } = {}
+): IRouteConfig {
+  return {
+    name: options.name || 'socket-handler-route',
+    priority: options.priority !== undefined ? options.priority : 50,
+    match: {
+      domains,
+      ports,
+      ...(options.path && { path: options.path })
+    },
+    action: {
+      type: 'socket-handler',
+      socketHandler: handler
+    }
+  };
+}
+
+/**
+ * Pre-built socket handlers for common use cases
+ */
+export const SocketHandlers = {
+  /**
+   * Simple echo server handler
+   */
+  echo: (socket: plugins.net.Socket) => {
+    socket.write('ECHO SERVER READY\n');
+    socket.on('data', data => socket.write(data));
+  },
+  
+  /**
+   * TCP proxy handler
+   */
+  proxy: (targetHost: string, targetPort: number) => (socket: plugins.net.Socket) => {
+    const target = plugins.net.connect(targetPort, targetHost);
+    socket.pipe(target);
+    target.pipe(socket);
+    socket.on('close', () => target.destroy());
+    target.on('close', () => socket.destroy());
+    target.on('error', (err) => {
+      console.error('Proxy target error:', err);
+      socket.destroy();
+    });
+  },
+  
+  /**
+   * Line-based protocol handler
+   */
+  lineProtocol: (handler: (line: string, socket: plugins.net.Socket) => void) => (socket: plugins.net.Socket) => {
+    let buffer = '';
+    socket.on('data', (data) => {
+      buffer += data.toString();
+      const lines = buffer.split('\n');
+      buffer = lines.pop() || '';
+      lines.forEach(line => {
+        if (line.trim()) {
+          handler(line.trim(), socket);
+        }
+      });
+    });
+  },
+  
+  /**
+   * Simple HTTP response handler (for testing)
+   */
+  httpResponse: (statusCode: number, body: string) => (socket: plugins.net.Socket) => {
+    const response = [
+      `HTTP/1.1 ${statusCode} ${statusCode === 200 ? 'OK' : 'Error'}`,
+      'Content-Type: text/plain',
+      `Content-Length: ${body.length}`,
+      'Connection: close',
+      '',
+      body
+    ].join('\r\n');
+    
+    socket.write(response);
+    socket.end();
+  }
+};