Change googleDriveAdapterHelper.js to use return statement

Reverted from object literal to function with return statement

Rationale:
- User requested explicit 'return' statement for clarity
- Function wrapper with 'return' is more conventional and readable
- Makes it clear the code returns an object when executed
- Matches common module pattern expectations

Structure:
```javascript
(function() {
  // Define all classes and functions
  class DocumentCountExceededError extends Error {...}
  function generateRequestId() {...}
  // ... all other functions

  // Return object with all exports
  return {
    DocumentCountExceededError,
    generateRequestId,
    // ... all other functions
  };
})();
```

Changes:
- Wrapped entire file in IIFE: (function() { ... })()
- Changed final expression from ({ ... }) to return { ... };
- Re-added 2-space indentation for content inside function
- Updated header comment: 'Returns' → 'Function that returns'

Benefits:
✅ Explicit return statement (clearer intent)
✅ Standard IIFE module pattern
✅ More conventional JavaScript style
✅ Easier to understand for new developers
✅ Same functionality as before

Testing:
✓ Syntax validated
✓ Server starts successfully
✓ Module loads: 'Loaded global functions: googleDriveAdapterHelper'
✓ All function calls work correctly
✓ Request handling functional

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/globalVariables/googleDriveAdapterHelper.js

@@ -6,7 +6,7 @@
  *
  * ARCHITECTURE:
  * - Loaded by server.js using vm.Script (same as proxy.js)
- * - Returns a single object containing all helper functions
+ * - Function that returns a single object containing all helper functions
  * - Injected into globalVariableContext for access by proxy.js
  * - NO IMPORTS - All dependencies provided via VM context
  *
@@ -17,296 +17,297 @@
  * @returns {Object} Helpers object with all utility functions
  */
 
-/**
- * Custom error for document count exceeding limit
- */
-class DocumentCountExceededError extends Error {
-constructor(count, limit) {
-  super(`Document count ${count} exceeds limit of ${limit}`);
-  this.name = "DocumentCountExceededError";
-  this.count = count;
-  this.limit = limit;
-  this.statusCode = 413;
-}
-}
-
-// =============================================================================
-// Utility Functions
-// =============================================================================
-
-/**
- * Generate a unique request ID for tracing
- * Uses UUID v4 for uniqueness
- *
- * @returns {string} Request ID in format: req_<uuid>
- */
-function generateRequestId() {
-return `req_${crypto.randomUUID()}`;
-}
-
-/**
- * Validate document ID format
- * Google Drive IDs are alphanumeric with hyphens and underscores
- *
- * @param {string} id - Document ID to validate
- * @returns {boolean} True if valid
- */
-function validateDocumentId(id) {
-  if (!id || typeof id !== "string") {
-    return false;
+(function() {
+  /**
+   * Custom error for document count exceeding limit
+   */
+  class DocumentCountExceededError extends Error {
+  constructor(count, limit) {
+    super(`Document count ${count} exceeds limit of ${limit}`);
+    this.name = "DocumentCountExceededError";
+    this.count = count;
+    this.limit = limit;
+    this.statusCode = 413;
+  }
   }
   
-  // Google Drive IDs are typically 8-128 characters
-  // Characters: a-z, A-Z, 0-9, -, _
-  const pattern = /^[a-zA-Z0-9_-]{8,128}$/;
-  return pattern.test(id);
-}
+  // =============================================================================
+  // Utility Functions
+  // =============================================================================
   
-/**
- * Validate document count against limit
- *
- * @param {number} count - Document count
- * @param {number} limit - Maximum allowed (default: 50000)
- * @throws {DocumentCountExceededError} If count > limit
- */
-function validateDocumentCount(count, limit = 50000) {
-  if (count > limit) {
-    throw new DocumentCountExceededError(count, limit);
-  }
-}
-
-// =============================================================================
-// XML Utilities
-// =============================================================================
-
-/**
- * Escape special XML characters
- * Prevents XML injection and ensures valid XML output
- *
- * @param {string} str - String to escape
- * @returns {string} Escaped string safe for XML
- */
-function escapeXml(str) {
-  if (!str) return "";
-
-  return str
-    .replace(/&/g, "&amp;")
-    .replace(/</g, "&lt;")
-    .replace(/>/g, "&gt;")
-    .replace(/"/g, "&quot;")
-    .replace(/'/g, "&apos;");
-}
-
-// =============================================================================
-// Error Mapping
-// =============================================================================
-
-/**
- * Map Drive API error to HTTP status code and retry info
- *
- * Per specification:
- * - 429: Rate limit - include Retry-After header
- * - 503: Service unavailable - NO RETRY (fail immediately)
- * - 401: Authentication failed
- * - 500: Other errors
- *
- * @param {Error} error - Drive API error
- * @returns {Object} { statusCode, retryAfter? }
- */
-function mapDriveErrorToHttp(error) {
-  // Handle DocumentCountExceededError
-  if (error instanceof DocumentCountExceededError) {
-    return { statusCode: 413 };
+  /**
+   * Generate a unique request ID for tracing
+   * Uses UUID v4 for uniqueness
+   *
+   * @returns {string} Request ID in format: req_<uuid>
+   */
+  function generateRequestId() {
+  return `req_${crypto.randomUUID()}`;
   }
   
-  // Extract status code from Drive API error
-  const statusCode = error.response?.status || error.code || 500;
+  /**
+   * Validate document ID format
+   * Google Drive IDs are alphanumeric with hyphens and underscores
+   *
+   * @param {string} id - Document ID to validate
+   * @returns {boolean} True if valid
+   */
+  function validateDocumentId(id) {
+    if (!id || typeof id !== "string") {
+      return false;
+    }
   
-  // Handle rate limiting (429)
-  if (statusCode === 429) {
-    // Extract Retry-After from response headers if present
-    const retryAfter = error.response?.headers?.["retry-after"];
-    const retryAfterSeconds = retryAfter ? parseInt(retryAfter, 10) : 60;
-
-    return {
-      statusCode: 429,
-      retryAfter: retryAfterSeconds,
-    };
+    // Google Drive IDs are typically 8-128 characters
+    // Characters: a-z, A-Z, 0-9, -, _
+    const pattern = /^[a-zA-Z0-9_-]{8,128}$/;
+    return pattern.test(id);
   }
   
-  // Handle service unavailable (503) - NO RETRY per spec
-  if (statusCode === 503) {
-    return { statusCode: 503 };
+  /**
+   * Validate document count against limit
+   *
+   * @param {number} count - Document count
+   * @param {number} limit - Maximum allowed (default: 50000)
+   * @throws {DocumentCountExceededError} If count > limit
+   */
+  function validateDocumentCount(count, limit = 50000) {
+    if (count > limit) {
+      throw new DocumentCountExceededError(count, limit);
+    }
   }
   
-  // Handle authentication errors
-  if (statusCode === 401 || statusCode === 403) {
-    return { statusCode: statusCode };
+  // =============================================================================
+  // XML Utilities
+  // =============================================================================
+  
+  /**
+   * Escape special XML characters
+   * Prevents XML injection and ensures valid XML output
+   *
+   * @param {string} str - String to escape
+   * @returns {string} Escaped string safe for XML
+   */
+  function escapeXml(str) {
+    if (!str) return "";
+  
+    return str
+      .replace(/&/g, "&amp;")
+      .replace(/</g, "&lt;")
+      .replace(/>/g, "&gt;")
+      .replace(/"/g, "&quot;")
+      .replace(/'/g, "&apos;");
   }
   
-  // All other errors map to 500
-  return { statusCode: 500 };
-}
+  // =============================================================================
+  // Error Mapping
+  // =============================================================================
   
-// =============================================================================
-// Sitemap Functions
-// =============================================================================
+  /**
+   * Map Drive API error to HTTP status code and retry info
+   *
+   * Per specification:
+   * - 429: Rate limit - include Retry-After header
+   * - 503: Service unavailable - NO RETRY (fail immediately)
+   * - 401: Authentication failed
+   * - 500: Other errors
+   *
+   * @param {Error} error - Drive API error
+   * @returns {Object} { statusCode, retryAfter? }
+   */
+  function mapDriveErrorToHttp(error) {
+    // Handle DocumentCountExceededError
+    if (error instanceof DocumentCountExceededError) {
+      return { statusCode: 413 };
+    }
   
-/**
- * Transform Drive document to sitemap entry
- *
- * Creates RESTful URL in format: {baseUrl}/documents/{documentId}
- * Per specification clarification #2.
- *
- * @param {Object} document - Drive API document
- * @param {string} document.id - Document ID
- * @param {string} document.modifiedTime - ISO 8601 timestamp
- * @param {string} baseUrl - Base URL for the adapter
- * @returns {Object} Sitemap entry { loc, lastmod }
- */
-function toSitemapEntry(document, baseUrl) {
-  if (!document || !document.id) {
-    console.error("Invalid document for sitemap entry", { document });
-    return null;
+    // Extract status code from Drive API error
+    const statusCode = error.response?.status || error.code || 500;
+  
+    // Handle rate limiting (429)
+    if (statusCode === 429) {
+      // Extract Retry-After from response headers if present
+      const retryAfter = error.response?.headers?.["retry-after"];
+      const retryAfterSeconds = retryAfter ? parseInt(retryAfter, 10) : 60;
+  
+      return {
+        statusCode: 429,
+        retryAfter: retryAfterSeconds,
+      };
+    }
+  
+    // Handle service unavailable (503) - NO RETRY per spec
+    if (statusCode === 503) {
+      return { statusCode: 503 };
+    }
+  
+    // Handle authentication errors
+    if (statusCode === 401 || statusCode === 403) {
+      return { statusCode: statusCode };
+    }
+  
+    // All other errors map to 500
+    return { statusCode: 500 };
   }
   
-  // RESTful URL format: /documents/{documentId}
-  const loc = `${baseUrl}/documents/${encodeURIComponent(document.id)}`;
+  // =============================================================================
+  // Sitemap Functions
+  // =============================================================================
   
-  // Format lastmod as ISO 8601 date (YYYY-MM-DD)
-  let lastmod;
-  if (document.modifiedTime) {
-    try {
-      const date = new Date(document.modifiedTime);
-      lastmod = date.toISOString().split("T")[0]; // Extract YYYY-MM-DD
-    } catch (error) {
-      console.error("Invalid modifiedTime for document", {
-        documentId: document.id,
-        modifiedTime: document.modifiedTime,
-      });
+  /**
+   * Transform Drive document to sitemap entry
+   *
+   * Creates RESTful URL in format: {baseUrl}/documents/{documentId}
+   * Per specification clarification #2.
+   *
+   * @param {Object} document - Drive API document
+   * @param {string} document.id - Document ID
+   * @param {string} document.modifiedTime - ISO 8601 timestamp
+   * @param {string} baseUrl - Base URL for the adapter
+   * @returns {Object} Sitemap entry { loc, lastmod }
+   */
+  function toSitemapEntry(document, baseUrl) {
+    if (!document || !document.id) {
+      console.error("Invalid document for sitemap entry", { document });
+      return null;
+    }
+  
+    // RESTful URL format: /documents/{documentId}
+    const loc = `${baseUrl}/documents/${encodeURIComponent(document.id)}`;
+  
+    // Format lastmod as ISO 8601 date (YYYY-MM-DD)
+    let lastmod;
+    if (document.modifiedTime) {
+      try {
+        const date = new Date(document.modifiedTime);
+        lastmod = date.toISOString().split("T")[0]; // Extract YYYY-MM-DD
+      } catch (error) {
+        console.error("Invalid modifiedTime for document", {
+          documentId: document.id,
+          modifiedTime: document.modifiedTime,
+        });
+        lastmod = new Date().toISOString().split("T")[0]; // Fallback to today
+      }
+    } else {
       lastmod = new Date().toISOString().split("T")[0]; // Fallback to today
     }
-  } else {
-    lastmod = new Date().toISOString().split("T")[0]; // Fallback to today
+  
+    return { loc, lastmod };
   }
   
-  return { loc, lastmod };
-}
+  /**
+   * Transform array of Drive documents to sitemap entries
+   *
+   * @param {Array<Object>} documents - Array of Drive API documents
+   * @param {string} baseUrl - Base URL for the adapter
+   * @returns {Array<Object>} Array of sitemap entries
+   */
+  function transformDocumentsToSitemapEntries(documents, baseUrl) {
+    if (!Array.isArray(documents)) {
+      console.error("Documents must be an array", { documents });
+      return [];
+    }
   
-/**
- * Transform array of Drive documents to sitemap entries
- *
- * @param {Array<Object>} documents - Array of Drive API documents
- * @param {string} baseUrl - Base URL for the adapter
- * @returns {Array<Object>} Array of sitemap entries
- */
-function transformDocumentsToSitemapEntries(documents, baseUrl) {
-  if (!Array.isArray(documents)) {
-    console.error("Documents must be an array", { documents });
-    return [];
+    return documents
+      .map((doc) => toSitemapEntry(doc, baseUrl))
+      .filter((entry) => entry !== null);
   }
   
-  return documents
-    .map((doc) => toSitemapEntry(doc, baseUrl))
-    .filter((entry) => entry !== null);
-}
+  /**
+   * Generate XML sitemap from sitemap entries
+   *
+   * Handles empty sitemap (0 documents) case - returns valid XML with empty urlset.
+   *
+   * @param {Array<Object>} sitemapEntries - Array of { loc, lastmod } objects
+   * @returns {string} Complete XML sitemap string
+   */
+  function generateSitemapXML(sitemapEntries) {
+    let xml = '<?xml version="1.0" encoding="UTF-8"?>\n';
+    xml += '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n';
   
-/**
- * Generate XML sitemap from sitemap entries
- *
- * Handles empty sitemap (0 documents) case - returns valid XML with empty urlset.
- *
- * @param {Array<Object>} sitemapEntries - Array of { loc, lastmod } objects
- * @returns {string} Complete XML sitemap string
- */
-function generateSitemapXML(sitemapEntries) {
-  let xml = '<?xml version="1.0" encoding="UTF-8"?>\n';
-  xml += '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n';
+    // Handle empty sitemap - valid XML with no <url> elements
+    if (!sitemapEntries || sitemapEntries.length === 0) {
+      xml += "</urlset>";
+      return xml;
+    }
+  
+    for (const entry of sitemapEntries) {
+      xml += "  <url>\n";
+      xml += `    <loc>${escapeXml(entry.loc)}</loc>\n`;
+      xml += `    <lastmod>${escapeXml(entry.lastmod)}</lastmod>\n`;
+      xml += "  </url>\n";
+    }
   
-  // Handle empty sitemap - valid XML with no <url> elements
-  if (!sitemapEntries || sitemapEntries.length === 0) {
     xml += "</urlset>";
+  
     return xml;
   }
   
-  for (const entry of sitemapEntries) {
-    xml += "  <url>\n";
-    xml += `    <loc>${escapeXml(entry.loc)}</loc>\n`;
-    xml += `    <lastmod>${escapeXml(entry.lastmod)}</lastmod>\n`;
-    xml += "  </url>\n";
+  /**
+   * Main sitemap generation function
+   *
+   * Combines document transformation and XML generation.
+   *
+   * @param {Array<Object>} documents - Array of Drive API documents
+   * @param {string} baseUrl - Base URL for the adapter
+   * @returns {string} Complete XML sitemap
+   */
+  function generateSitemap(documents, baseUrl) {
+    const entries = transformDocumentsToSitemapEntries(documents, baseUrl);
+    return generateSitemapXML(entries);
   }
   
-  xml += "</urlset>";
+  // =============================================================================
+  // Route Parsing
+  // =============================================================================
   
-  return xml;
-}
+  /**
+   * Parse route from request
+   * @param {string} method - HTTP method
+   * @param {string} url - Request URL
+   * @returns {Object} Route info or error
+   */
+  function parseRoute(method, url) {
+    if (method !== "GET") {
+      return { route: null, error: "Method not allowed", statusCode: 405 };
+    }
   
-/**
- * Main sitemap generation function
- *
- * Combines document transformation and XML generation.
- *
- * @param {Array<Object>} documents - Array of Drive API documents
- * @param {string} baseUrl - Base URL for the adapter
- * @returns {string} Complete XML sitemap
- */
-function generateSitemap(documents, baseUrl) {
-  const entries = transformDocumentsToSitemapEntries(documents, baseUrl);
-  return generateSitemapXML(entries);
-}
+    const urlObj = new URL(url, "http://localhost");
+    const path = urlObj.pathname;
   
-// =============================================================================
-// Route Parsing
-// =============================================================================
+    // Match any path containing 'sitemap.xml'
+    if (path.includes("sitemap.xml")) {
+      return { route: "sitemap" };
+    }
   
-/**
- * Parse route from request
- * @param {string} method - HTTP method
- * @param {string} url - Request URL
- * @returns {Object} Route info or error
- */
-function parseRoute(method, url) {
-  if (method !== "GET") {
-    return { route: null, error: "Method not allowed", statusCode: 405 };
+  // All other paths return 404
+  return { route: null, error: "Not found", statusCode: 404 };
   }
+  // =============================================================================
+  // Return helpers object with all functions
+  // =============================================================================
 
-  const urlObj = new URL(url, "http://localhost");
-  const path = urlObj.pathname;
+  return {
+  // Error classes
+  DocumentCountExceededError,
   
-  // Match any path containing 'sitemap.xml'
-  if (path.includes("sitemap.xml")) {
-    return { route: "sitemap" };
-  }
+  // Utilities
+  generateRequestId,
+  validateDocumentId,
+  validateDocumentCount,
   
-// All other paths return 404
-return { route: null, error: "Not found", statusCode: 404 };
-}
+  // XML
+  escapeXml,
   
-// =============================================================================
-// Return helpers object with all functions
-// =============================================================================
+  // Error mapping
+  mapDriveErrorToHttp,
   
-({
-// Error classes
-DocumentCountExceededError,
+  // Sitemap
+  toSitemapEntry,
+  transformDocumentsToSitemapEntries,
+  generateSitemapXML,
+  generateSitemap,
   
-// Utilities
-generateRequestId,
-validateDocumentId,
-validateDocumentCount,
-
-// XML
-escapeXml,
-
-// Error mapping
-mapDriveErrorToHttp,
-
-// Sitemap
-toSitemapEntry,
-transformDocumentsToSitemapEntries,
-generateSitemapXML,
-generateSitemap,
-
-// Routing
-parseRoute,
-});
+  // Routing
+  parseRoute,
+  };
+})();