1MCP Server

import { JSONRPCMessage } from '@modelcontextprotocol/sdk/types.js'; import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'; import { StdioProxyTransport } from './stdioProxyTransport.js'; // Mock the SDK transports vi.mock('@modelcontextprotocol/sdk/server/stdio.js', () => ({ StdioServerTransport: vi.fn(() => ({ start: vi.fn().mockResolvedValue(undefined), close: vi.fn().mockResolvedValue(undefined), send: vi.fn().mockResolvedValue(undefined), onmessage: undefined, onerror: undefined, onclose: undefined, })), })); vi.mock('@modelcontextprotocol/sdk/client/streamableHttp.js', () => ({ StreamableHTTPClientTransport: vi.fn(() => ({ start: vi.fn().mockResolvedValue(undefined), close: vi.fn().mockResolvedValue(undefined), send: vi.fn().mockResolvedValue(undefined), onmessage: undefined, onerror: undefined, onclose: undefined, })), })); describe('StdioProxyTransport', () => { let proxy: StdioProxyTransport; beforeEach(() => { vi.clearAllMocks(); }); afterEach(async () => { if (proxy) { await proxy.close(); } }); describe('constructor', () => { it('should create proxy with server URL', () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); expect(proxy).toBeDefined(); }); it('should create proxy with tags', () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', tags: ['web', 'api'], }); expect(proxy).toBeDefined(); }); it('should create proxy with timeout', () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', timeout: 5000, }); expect(proxy).toBeDefined(); }); }); describe('start', () => { it('should start both transports in correct order', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); // Verify both transports were started expect(proxy['httpTransport'].start).toHaveBeenCalled(); expect(proxy['stdioTransport'].start).toHaveBeenCalled(); }); it('should set up message forwarding before starting transports', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); // Verify message handlers are set expect(proxy['stdioTransport'].onmessage).toBeDefined(); expect(proxy['httpTransport'].onmessage).toBeDefined(); expect(proxy['stdioTransport'].onerror).toBeDefined(); expect(proxy['httpTransport'].onerror).toBeDefined(); expect(proxy['stdioTransport'].onclose).toBeDefined(); expect(proxy['httpTransport'].onclose).toBeDefined(); }); }); describe('message forwarding', () => { it('should forward messages from STDIO to HTTP', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); const message: JSONRPCMessage = { jsonrpc: '2.0', method: 'initialize', id: 1, params: {}, }; // Simulate STDIO message await proxy['stdioTransport'].onmessage!(message); // Verify forwarded to HTTP transport expect(proxy['httpTransport'].send).toHaveBeenCalledWith(message); }); it('should forward messages from HTTP to STDIO', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); const message: JSONRPCMessage = { jsonrpc: '2.0', result: { capabilities: {} }, id: 1, }; // Simulate HTTP message await proxy['httpTransport'].onmessage!(message); // Verify forwarded to STDIO transport expect(proxy['stdioTransport'].send).toHaveBeenCalledWith(message); }); it('should handle errors during STDIO to HTTP forwarding', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); // Make send throw error proxy['httpTransport'].send = vi.fn().mockRejectedValue(new Error('Send failed')); const message: JSONRPCMessage = { jsonrpc: '2.0', method: 'test', id: 1, params: {}, }; // Should not throw, error should be logged await expect(proxy['stdioTransport'].onmessage!(message)).resolves.not.toThrow(); }); it('should handle errors during HTTP to STDIO forwarding', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); // Make send throw error proxy['stdioTransport'].send = vi.fn().mockRejectedValue(new Error('Send failed')); const message: JSONRPCMessage = { jsonrpc: '2.0', result: {}, id: 1, }; // Should not throw, error should be logged await expect(proxy['httpTransport'].onmessage!(message)).resolves.not.toThrow(); }); }); describe('close', () => { it('should close both transports', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); await proxy.close(); expect(proxy['httpTransport'].close).toHaveBeenCalled(); expect(proxy['stdioTransport'].close).toHaveBeenCalled(); }); it('should handle close when not connected', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); // Should not throw when closing without starting await expect(proxy.close()).resolves.not.toThrow(); }); it('should handle close errors gracefully', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); // Make close throw error proxy['httpTransport'].close = vi.fn().mockRejectedValue(new Error('Close failed')); // Should not throw, error should be logged await expect(proxy.close()).resolves.not.toThrow(); }); it('should not cause infinite recursion when onclose handlers trigger', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); // Track how many times the actual cleanup logic runs let cleanupExecutions = 0; // Make transports trigger their onclose handlers when close() is called const httpCloseMock = vi.fn(async () => { cleanupExecutions++; // Simulate real transport behavior: trigger onclose when closed if (proxy['httpTransport'].onclose) { await proxy['httpTransport'].onclose(); } }); const stdioCloseMock = vi.fn(async () => { cleanupExecutions++; // Simulate real transport behavior: trigger onclose when closed if (proxy['stdioTransport'].onclose) { await proxy['stdioTransport'].onclose(); } }); proxy['httpTransport'].close = httpCloseMock; proxy['stdioTransport'].close = stdioCloseMock; // This should not cause stack overflow or throw error await expect(proxy.close()).resolves.not.toThrow(); // Cleanup should execute exactly once (both transports closed once) expect(httpCloseMock).toHaveBeenCalledTimes(1); expect(stdioCloseMock).toHaveBeenCalledTimes(1); expect(cleanupExecutions).toBe(2); // One for http, one for stdio }); }); describe('transport lifecycle handlers', () => { it('should handle STDIO transport close', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); const closeSpy = vi.spyOn(proxy, 'close'); // Trigger STDIO close await proxy['stdioTransport'].onclose!(); expect(closeSpy).toHaveBeenCalled(); }); it('should handle HTTP transport close', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); const closeSpy = vi.spyOn(proxy, 'close'); // Trigger HTTP close await proxy['httpTransport'].onclose!(); expect(closeSpy).toHaveBeenCalled(); }); it('should handle STDIO transport errors', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); const error = new Error('STDIO error'); // Should not throw expect(() => proxy['stdioTransport'].onerror!(error)).not.toThrow(); }); it('should handle HTTP transport errors', async () => { proxy = new StdioProxyTransport({ serverUrl: 'http://localhost:3050/mcp', }); await proxy.start(); const error = new Error('HTTP error'); // Should not throw expect(() => proxy['httpTransport'].onerror!(error)).not.toThrow(); }); }); });