Fix jsdom 28 WebSocket cross-realm Event incompatibility

packages/roslib/src/core/transport/WebSocketTransportFactory.ts

@@ -1,5 +1,41 @@
 import type { ITransport, ITransportFactory } from "./Transport.ts";
 
+/**
+ * Detect if we're running in a jsdom environment.
+ * jsdom provides WebSocket but has cross-realm issues with Event objects.
+ */
+function isJsdomEnvironment(): boolean {
+  // Check for jsdom-specific navigator.userAgent
+  try {
+    if (navigator.userAgent.includes("jsdom")) {
+      return true;
+    }
+  } catch {
+    // navigator not available
+  }
+
+  // Check for jsdom-specific window constructor name
+  if (typeof window !== "undefined") {
+    const windowConstructorName = window.constructor.name.toLowerCase();
+    if (windowConstructorName === "jsdom") {
+      return true;
+    }
+  }
+
+  // Check for jsdom-specific globals that aren't present in real browsers
+  if (typeof globalThis !== "undefined") {
+    // jsdom creates a special Symbol for internal use
+    const hasJsdomSymbol = Object.getOwnPropertySymbols(globalThis).some(
+      (sym) => sym.toString().includes("jsdom"),
+    );
+    if (hasJsdomSymbol) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 /**
  * A transport factory that uses WebSockets to send and receive messages.
  * Will use the native `WebSocket` class if available, otherwise falls back
@@ -12,7 +48,9 @@ export const WebSocketTransportFactory: ITransportFactory = async (
   url: string,
 ): Promise<ITransport> => {
   // Browsers, Deno, Bun, and Node 22+ support WebSockets natively
-  if (typeof WebSocket === "function") {
+  // However, jsdom has cross-realm issues with WebSocket events, so we
+  // need to use the ws package in jsdom environments
+  if (typeof WebSocket === "function" && !isJsdomEnvironment()) {
     const transportModule = await import("./NativeWebSocketTransport.ts");
     const { NativeWebSocketTransport } = transportModule;
     const socket = new WebSocket(url);

packages/roslib/test/transport.test.ts

@@ -648,13 +648,14 @@ describe("Transport", () => {
   });
 
   describe("WebSocketTransportFactory", () => {
-    it("uses native WebSocket when available", async () => {
+    it("uses WsWebSocketTransport in jsdom environment", async () => {
       vi.stubGlobal("WebSocket", WebSocket);
       expect(typeof WebSocket).toBe("function");
 
+      // In jsdom environment, should use WsWebSocketTransport to avoid cross-realm Event issues
       const transport = await WebSocketTransportFactory("ws://localhost:9090");
 
-      expect(transport).toBeInstanceOf(NativeWebSocketTransport);
+      expect(transport).toBeInstanceOf(WsWebSocketTransport);
     });
 
     it("uses ws package WebSocket when native WebSocket is not available", async () => {