YouTube Transcript DL MCP Server

/** * TDD Tests for ESM Migration - MCP SDK Compatibility * * These tests MUST pass after ESM migration to ensure MCP SDK works correctly. * Focus: MCP SDK imports, server initialization, and transport functionality */ import { jest } from '@jest/globals'; import { fileURLToPath } from 'url'; import * as path from 'path'; // Get current file directory for ESM const __filename = fileURLToPath(import.meta.url); const __dirname = path.dirname(__filename); describe('ESM Migration - MCP SDK Compatibility', () => { describe('MCP SDK Module Imports', () => { it('should import Server from MCP SDK', async () => { const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); expect(Server).toBeDefined(); expect(typeof Server).toBe('function'); // Should be able to instantiate const serverConfig = { name: 'test-server', version: '1.0.0', }; const serverOptions = { capabilities: { tools: {}, }, }; expect(() => new Server(serverConfig, serverOptions)).not.toThrow(); }); it('should import transport modules correctly', async () => { // Test stdio transport const { StdioServerTransport } = await import('@modelcontextprotocol/sdk/server/stdio.js'); expect(StdioServerTransport).toBeDefined(); expect(typeof StdioServerTransport).toBe('function'); // Test SSE transport if available try { const { SSEServerTransport } = await import('@modelcontextprotocol/sdk/server/sse.js'); expect(SSEServerTransport).toBeDefined(); } catch (error) { // SSE transport might not be available in all versions console.warn('SSE transport not available:', error); } }); it('should import protocol types correctly', async () => { const protocol = await import('@modelcontextprotocol/sdk/types.js'); expect(protocol).toBeDefined(); // Should have common types available expect(protocol).toHaveProperty('ListToolsRequestSchema'); expect(protocol).toHaveProperty('CallToolRequestSchema'); }); }); describe('Server Initialization with ESM', () => { it('should create MCP server instance with ESM imports', async () => { const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); const server = new Server( { name: 'youtube-transcript-mcp', version: '1.0.0', }, { capabilities: { tools: {}, }, } ); expect(server).toBeDefined(); expect(typeof server.setRequestHandler).toBe('function'); expect(typeof server.connect).toBe('function'); }); it('should set up request handlers without import errors', async () => { const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); const { ListToolsRequestSchema, CallToolRequestSchema } = await import('@modelcontextprotocol/sdk/types.js'); const server = new Server( { name: 'test-server', version: '1.0.0', }, { capabilities: { tools: {}, }, } ); // Should be able to set request handlers expect(() => { server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: [] })); server.setRequestHandler(CallToolRequestSchema, async () => ({ content: [{ type: 'text', text: 'test' }] })); }).not.toThrow(); }); }); describe('Transport Compatibility', () => { it('should create stdio transport without errors', async () => { const { StdioServerTransport } = await import('@modelcontextprotocol/sdk/server/stdio.js'); expect(() => { new StdioServerTransport(); }).not.toThrow(); }); it('should handle transport connection setup', async () => { const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); const { StdioServerTransport } = await import('@modelcontextprotocol/sdk/server/stdio.js'); const server = new Server( { name: 'test', version: '1.0.0' }, { capabilities: { tools: {} } } ); const transport = new StdioServerTransport(); // Should be able to connect (though we won't actually connect in tests) expect(typeof server.connect).toBe('function'); expect(transport).toBeDefined(); }); }); describe('Tool Registration and Execution', () => { it('should register tools with correct schemas', async () => { const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); const { ListToolsRequestSchema, CallToolRequestSchema } = await import('@modelcontextprotocol/sdk/types.js'); const server = new Server( { name: 'youtube-transcript-mcp', version: '1.0.0', }, { capabilities: { tools: {}, }, } ); const tools = [ { name: 'get_transcript', description: 'Extract transcript from a single YouTube video', inputSchema: { type: 'object', properties: { videoId: { type: 'string' }, language: { type: 'string', default: 'en' }, format: { type: 'string', enum: ['text', 'json', 'srt'], default: 'json' } }, required: ['videoId'] } } ]; // Should register tools handler without errors expect(() => { server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: tools })); }).not.toThrow(); }); it('should handle tool execution with proper error handling', async () => { const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); const { CallToolRequestSchema } = await import('@modelcontextprotocol/sdk/types.js'); const server = new Server( { name: 'test-server', version: '1.0.0', }, { capabilities: { tools: {}, }, } ); // Should handle tool calls without import/export errors expect(() => { server.setRequestHandler(CallToolRequestSchema, async (request) => { const { name, arguments: args } = request.params; if (name === 'get_transcript') { return { content: [{ type: 'text', text: `Transcript for video: ${args.videoId}` }] }; } throw new Error(`Unknown tool: ${name}`); }); }).not.toThrow(); }); }); describe('Error Handling and ESM Compatibility', () => { it('should handle MCP errors without import issues', async () => { const { McpError, ErrorCode } = await import('@modelcontextprotocol/sdk/types.js'); expect(McpError).toBeDefined(); expect(ErrorCode).toBeDefined(); // Should be able to create and throw MCP errors const error = new McpError(ErrorCode.InvalidRequest, 'Test error'); expect(error).toBeInstanceOf(Error); expect(error.code).toBe(ErrorCode.InvalidRequest); }); it('should handle async operations in ESM context', async () => { const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); const { CallToolRequestSchema } = await import('@modelcontextprotocol/sdk/types.js'); const server = new Server( { name: 'test', version: '1.0.0' }, { capabilities: { tools: {} } } ); // Should handle async tool execution let handlerCalled = false; server.setRequestHandler(CallToolRequestSchema, async (request) => { handlerCalled = true; // Simulate async operation await new Promise(resolve => setTimeout(resolve, 1)); return { content: [{ type: 'text', text: 'async result' }] }; }); expect(handlerCalled).toBe(false); // Handler not called yet }); }); describe('TypeScript and ESM Type Definitions', () => { it('should have correct TypeScript types for MCP SDK', async () => { // Import types should work const types = await import('@modelcontextprotocol/sdk/types.js'); // Should have tool-related types expect(types.ListToolsRequestSchema).toBeDefined(); expect(types.CallToolRequestSchema).toBeDefined(); // Should have server config types expect(types.ServerCapabilities).toBeDefined(); }); it('should support generic types in ESM context', async () => { const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); // TypeScript should infer types correctly const server = new Server( { name: 'typed-server', version: '1.0.0', }, { capabilities: { tools: {}, }, } ); expect(server).toBeDefined(); }); }); describe('Integration with YouTube Transcript Service', () => { it('should import both MCP SDK and YouTube transcript service', async () => { // Both imports should work together const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); const { YoutubeTranscript } = await import('youtube-transcript'); expect(Server).toBeDefined(); expect(YoutubeTranscript).toBeDefined(); // Should be able to use together const server = new Server( { name: 'integration-test', version: '1.0.0' }, { capabilities: { tools: {} } } ); expect(typeof YoutubeTranscript.fetchTranscript).toBe('function'); }); it('should handle service instantiation in ESM context', async () => { // Mock the service import const mockService = { getTranscript: jest.fn(), getCacheStats: jest.fn(), clearCache: jest.fn() }; // Should be able to create service instance expect(() => { const service = mockService; expect(service.getTranscript).toBeDefined(); }).not.toThrow(); }); }); });