YouTube Transcript DL MCP Server

/** * TDD Tests for ESM Migration - Import Resolution * * These tests MUST pass after ESM migration to ensure imports work correctly. * Focus: Import statements resolve correctly with .js extensions and ESM compatibility */ import { jest } from '@jest/globals'; import * as path from 'path'; import * as fs from 'fs'; import { fileURLToPath } from 'url'; // Get current file directory for ESM const __filename = fileURLToPath(import.meta.url); const __dirname = path.dirname(__filename); describe('ESM Migration - Import Resolution', () => { const srcDir = path.join(__dirname, '../../src'); const distDir = path.join(__dirname, '../../dist'); describe('TypeScript Configuration', () => { it('should have ESM module configuration in tsconfig.json', () => { const tsconfigPath = path.join(__dirname, '../../tsconfig.json'); const tsconfig = JSON.parse(fs.readFileSync(tsconfigPath, 'utf8')); expect(tsconfig.compilerOptions.module).toBe('ESNext'); expect(tsconfig.compilerOptions.target).toBe('ES2022'); expect(tsconfig.compilerOptions.moduleResolution).toBe('node'); expect(tsconfig.compilerOptions.allowSyntheticDefaultImports).toBe(true); expect(tsconfig.compilerOptions.esModuleInterop).toBe(true); }); it('should have correct output configuration for ESM', () => { const tsconfigPath = path.join(__dirname, '../../tsconfig.json'); const tsconfig = JSON.parse(fs.readFileSync(tsconfigPath, 'utf8')); expect(tsconfig.compilerOptions.outDir).toBe('./dist'); expect(tsconfig.compilerOptions.declaration).toBe(true); expect(tsconfig.compilerOptions.sourceMap).toBe(true); }); }); describe('Source File Import Statements', () => { const getSourceFiles = (dir: string): string[] => { const files: string[] = []; const entries = fs.readdirSync(dir, { withFileTypes: true }); for (const entry of entries) { const fullPath = path.join(dir, entry.name); if (entry.isDirectory()) { files.push(...getSourceFiles(fullPath)); } else if (entry.name.endsWith('.ts') && !entry.name.endsWith('.d.ts')) { files.push(fullPath); } } return files; }; it('should use ESM import syntax in all TypeScript files', () => { const sourceFiles = getSourceFiles(srcDir); expect(sourceFiles.length).toBeGreaterThan(0); for (const file of sourceFiles) { const content = fs.readFileSync(file, 'utf8'); // Should NOT use CommonJS require expect(content).not.toMatch(/\brequire\s*\(/); expect(content).not.toMatch(/module\.exports/); expect(content).not.toMatch(/exports\./); // Should use ESM syntax if (content.includes('import') || content.includes('export')) { expect(content).toMatch(/\bimport\b|\bexport\b/); } } }); it('should use relative imports with .js extensions in compiled output', async () => { // Build first if dist doesn't exist if (!fs.existsSync(distDir)) { const { exec } = await import('child_process'); const { promisify } = await import('util'); const execAsync = promisify(exec); await execAsync('npm run build', { cwd: path.join(__dirname, '../..') }); } const getCompiledFiles = (dir: string): string[] => { const files: string[] = []; try { const entries = fs.readdirSync(dir, { withFileTypes: true }); for (const entry of entries) { const fullPath = path.join(dir, entry.name); if (entry.isDirectory()) { files.push(...getCompiledFiles(fullPath)); } else if (entry.name.endsWith('.js')) { files.push(fullPath); } } } catch (error) { // Directory might not exist yet } return files; }; const compiledFiles = getCompiledFiles(distDir); if (compiledFiles.length > 0) { for (const file of compiledFiles) { const content = fs.readFileSync(file, 'utf8'); // Check for relative imports - they should have .js extensions const relativeImports = content.match(/from\s+['"]\.\.?\/[^'"]*['"];?/g) || []; for (const importStatement of relativeImports) { // Relative imports should end with .js if (!importStatement.includes('.js')) { fail(`Relative import without .js extension in ${file}: ${importStatement}`); } } } } }); }); describe('MCP SDK Import Compatibility', () => { it('should successfully import MCP SDK modules', async () => { // Test that we can import the MCP SDK without errors await expect(async () => { const { Server } = await import('@modelcontextprotocol/sdk/server/index.js'); expect(Server).toBeDefined(); expect(typeof Server).toBe('function'); }).not.toThrow(); }); it('should import MCP SDK with correct ESM syntax', async () => { const { StdioServerTransport } = await import('@modelcontextprotocol/sdk/server/stdio.js'); expect(StdioServerTransport).toBeDefined(); expect(typeof StdioServerTransport).toBe('function'); }); it('should handle MCP SDK types correctly', async () => { // Import types that should be available const sdk = await import('@modelcontextprotocol/sdk/types.js'); expect(sdk).toBeDefined(); }); }); describe('Third-party Package Imports', () => { it('should import CommonJS packages with ESM compatibility', async () => { // Test winston (CommonJS package) await expect(async () => { const winston = await import('winston'); expect(winston.createLogger).toBeDefined(); }).not.toThrow(); }); it('should import commander.js correctly', async () => { const { Command } = await import('commander'); expect(Command).toBeDefined(); expect(typeof Command).toBe('function'); }); it('should import express correctly', async () => { const express = await import('express'); expect(express.default).toBeDefined(); expect(typeof express.default).toBe('function'); }); it('should import uuid correctly', async () => { const { v4: uuidv4 } = await import('uuid'); expect(uuidv4).toBeDefined(); expect(typeof uuidv4).toBe('function'); }); it('should import youtube-transcript correctly', async () => { const { YoutubeTranscript } = await import('youtube-transcript'); expect(YoutubeTranscript).toBeDefined(); expect(YoutubeTranscript.fetchTranscript).toBeDefined(); }); }); describe('Dynamic Imports', () => { it('should support dynamic imports for optional dependencies', async () => { // Test dynamic import syntax const dynamicImport = await import('path'); expect(dynamicImport.join).toBeDefined(); }); it('should handle conditional imports correctly', async () => { // Test that conditional imports work const condition = true; if (condition) { const fs = await import('fs'); expect(fs.readFileSync).toBeDefined(); } }); }); describe('File Extension Resolution', () => { it('should resolve .js files from TypeScript imports', () => { // After compilation, .ts imports should become .js const indexPath = path.join(distDir, 'index.js'); if (fs.existsSync(indexPath)) { const content = fs.readFileSync(indexPath, 'utf8'); // Check that imports have .js extensions const imports = content.match(/from\s+['"][^'"]*['"];?/g) || []; for (const importStatement of imports) { if (importStatement.includes('./') || importStatement.includes('../')) { expect(importStatement).toMatch(/\.js['"];?/); } } } }); it('should not reference .ts files in compiled output', () => { const getJsFiles = (dir: string): string[] => { const files: string[] = []; try { const entries = fs.readdirSync(dir, { withFileTypes: true }); for (const entry of entries) { const fullPath = path.join(dir, entry.name); if (entry.isDirectory()) { files.push(...getJsFiles(fullPath)); } else if (entry.name.endsWith('.js')) { files.push(fullPath); } } } catch (error) { // Directory might not exist } return files; }; const jsFiles = getJsFiles(distDir); for (const file of jsFiles) { const content = fs.readFileSync(file, 'utf8'); // Should not reference .ts files expect(content).not.toMatch(/from\s+['"][^'"]*\.ts['"];?/); expect(content).not.toMatch(/import\([^)]*\.ts[^)]*\)/); } }); }); describe('require.main Compatibility', () => { it('should handle require.main check for ESM entry point', () => { const indexPath = path.join(srcDir, 'index.ts'); if (fs.existsSync(indexPath)) { const content = fs.readFileSync(indexPath, 'utf8'); // If using require.main check, it should be compatible if (content.includes('require.main')) { // Should use import.meta.url instead for ESM // Or conditional check for CommonJS compatibility expect(content).toMatch(/import\.meta\.url|require\.main/); } } }); it('should use ESM-compatible entry point detection', () => { const binPath = path.join(srcDir, 'bin/server.ts'); if (fs.existsSync(binPath)) { const content = fs.readFileSync(binPath, 'utf8'); // Should not rely on CommonJS-specific patterns expect(content).not.toMatch(/require\.main\s*===\s*module/); } }); }); });