fix(client): fix ping tests timing out due to MockTransport not responding

The MockTransport class in ping.test.ts was not responding to initialize
and ping requests, causing client.connect() to hang indefinitely and
tests to timeout. Updated MockTransport.send() to properly respond to
these requests with appropriate JSON-RPC responses.

Author: Br1an67

packages/client/test/client/ping.test.ts

@@ -3,7 +3,7 @@ import type { JSONRPCMessage } from '@modelcontextprotocol/core';
 import { Client } from '../../src/client/client.js';
 import type { Transport, TransportSendOptions } from '@modelcontextprotocol/core';
 
-// Mock Transport class
+// Mock Transport class that responds to initialize requests
 class MockTransport implements Transport {
     onclose?: () => void;
     onerror?: (error: Error) => void;
@@ -14,7 +14,33 @@ class MockTransport implements Transport {
     async close(): Promise<void> {
         this.onclose?.();
     }
-    async send(_message: JSONRPCMessage, _options?: TransportSendOptions): Promise<void> {}
+    async send(message: JSONRPCMessage, _options?: TransportSendOptions): Promise<void> {
+        // Respond to initialize requests so connect() doesn't hang
+        if ('method' in message && message.method === 'initialize' && 'id' in message) {
+            // Use queueMicrotask to simulate async response
+            queueMicrotask(() => {
+                this.onmessage?.({
+                    jsonrpc: '2.0',
+                    id: message.id as string | number,
+                    result: {
+                        protocolVersion: '2024-11-05',
+                        capabilities: {},
+                        serverInfo: { name: 'test-server', version: '1.0.0' }
+                    }
+                });
+            });
+        }
+        // Respond to ping requests
+        if ('method' in message && message.method === 'ping' && 'id' in message) {
+            queueMicrotask(() => {
+                this.onmessage?.({
+                    jsonrpc: '2.0',
+                    id: message.id as string | number,
+                    result: {}
+                });
+            });
+        }
+    }
 }
 
 // Helper interface to access private members for testing