update data transformation bug fixes

Author: MmagdyHafezZ

apps/api/src/common/interceptors/data-transform.interceptor.ts

@@ -195,6 +195,23 @@ export class DataTransformInterceptor implements NestInterceptor {
   private decodeValue(value: unknown): unknown {
     if (typeof value !== "string") return value;
 
+    // Handle compressed data with 'comp:' prefix
+    if (value.startsWith("comp:")) {
+      try {
+        const base64Data = value.slice(5); // Remove 'comp:' prefix
+        const decoded = Buffer.from(base64Data, "base64").toString("utf8");
+
+        try {
+          return JSON.parse(decoded);
+        } catch {
+          return decoded;
+        }
+      } catch {
+        return value;
+      }
+    }
+
+    // Handle regular base64 encoded data
     try {
       const decoded = Buffer.from(value, "base64").toString("utf8");
 

apps/api/src/helpers/data-transformer.ts

@@ -164,9 +164,24 @@ function encodeValue(value: unknown): string {
 function decodeValue(value: unknown): unknown {
   if (!value || typeof value !== "string") return value;
 
+  // Support 'comp:' prefix used by the web encoder for large strings
+  if (value.startsWith("comp:")) {
+    try {
+      const base64Data = value.slice(5);
+      const decoded = Buffer.from(base64Data, "base64").toString("utf8");
+      try {
+        return JSON.parse(decoded);
+      } catch {
+        return decoded;
+      }
+    } catch {
+      return value;
+    }
+  }
+
+  // Regular base64 decode
   try {
     const decoded = Buffer.from(value, "base64").toString("utf8");
-
     try {
       return JSON.parse(decoded);
     } catch {

apps/api/src/helpers/decoder.ts

@@ -3,11 +3,20 @@
 export function decodeIfBase64(value: string | null): string | null {
   if (!value) return null;
 
+  // Support 'comp:' prefix used by the web client for large strings
+  if (value.startsWith("comp:")) {
+    try {
+      const base64Data = value.slice(5);
+      const decoded = Buffer.from(base64Data, "base64").toString("utf8");
+      return decoded;
+    } catch {
+      return value;
+    }
+  }
+
   try {
     const decoded = Buffer.from(value, "base64").toString("utf8");
-
     const reEncoded = Buffer.from(decoded, "utf8").toString("base64");
-
     return reEncoded === value ? decoded : value;
   } catch {
     return value;

apps/api/src/middleware/data-transform.middleware.ts

@@ -211,9 +211,24 @@ export class DataTransformMiddleware implements NestMiddleware {
   private decodeValue(value: unknown): unknown {
     if (typeof value !== "string") return value;
 
+    // Handle compressed payloads with the 'comp:' prefix (matches web encoder)
+    if (value.startsWith("comp:")) {
+      try {
+        const base64Data = value.slice(5); // strip 'comp:'
+        const decoded = Buffer.from(base64Data, "base64").toString("utf8");
+        try {
+          return JSON.parse(decoded) as unknown;
+        } catch {
+          return decoded;
+        }
+      } catch {
+        return value;
+      }
+    }
+
+    // Fallback: regular base64 encoded strings
     try {
       const decoded = Buffer.from(value, "base64").toString("utf8");
-
       try {
         return JSON.parse(decoded) as unknown;
       } catch {