chore(backend.js): json processing optimisations

src/js/serverUtils.js

@@ -25,36 +25,41 @@ try {
   logger.error('Error loading replacements file:', { error: error.message });
 }
 
+// Optimized replaceJsonKeys function
 const replaceJsonKeys = (obj) => {
-  if (!obj || typeof obj !== 'object') return obj;
-
-  if (Array.isArray(obj)) {
-    return obj.map((item) => replaceJsonKeys(item));
-  }
-
-  const newObj = {};
-  Object.keys(obj).forEach((key) => {
-    // Replace key if it exists in replacements
-    const newKey = keyReplacements[key] || key;
-
-    // DEBUG: Log replacements when they happen
-    // if (newKey !== key) {
-    //   logger.debug(`Replacing key "${key}" with "${newKey}"`);
-    // }
-
-    // Also check if the value should be replaced (if it's a string)
-    let value = obj[key];
-    if (typeof value === 'string' && keyReplacements[value]) {
-      value = keyReplacements[value];
-      // logger.debug(`Replacing value "${obj[key]}" with "${value}"`);
+    if (!obj || typeof obj !== 'object') return obj;
+  
+    // Fast-path for arrays
+    if (Array.isArray(obj)) {
+      // Only process array if it has items
+      return obj.length > 0 ? obj.map(replaceJsonKeys) : obj;
     }
-
-    // Process value recursively if it's an object or array
-    newObj[newKey] = replaceJsonKeys(value);
-  });
-
-  return newObj;
-};
+  
+    const newObj = {};
+    const objKeys = Object.keys(obj);
+    
+    // Fast-path for empty objects
+    if (objKeys.length === 0) return obj;
+    
+    // Cache key check
+    const hasKeyReplacements = Object.keys(keyReplacements).length > 0;
+    
+    for (const key of objKeys) {
+      // Replace key if replacements exist
+      const newKey = hasKeyReplacements && keyReplacements[key] ? keyReplacements[key] : key;
+      let value = obj[key];
+      
+      // Replace string values if needed
+      if (hasKeyReplacements && typeof value === 'string' && keyReplacements[value]) {
+        value = keyReplacements[value];
+      }
+      
+      // Process recursively only if object/array
+      newObj[newKey] = (value && typeof value === 'object') ? replaceJsonKeys(value) : value;
+    }
+  
+    return newObj;
+  };
 
 // Utility regex function
 const sanitizeJsonOutput = (data) => {