another attempt

Author: RulaKhaled

packages/cloudflare/src/request.ts

@@ -51,12 +51,12 @@ export function wrapRequestHandler(
 
     const waitUntil = context?.waitUntil?.bind?.(context);
 
-    // Track whether flush has been scheduled to prevent duplicate calls
-    let flushScheduled = false;
+    // Track flush promise to ensure it's only scheduled once
+    let flushPromise: Promise<boolean> | null = null;
     const scheduleFlush = (timeout: number = 2000): void => {
-      if (!flushScheduled && waitUntil) {
-        flushScheduled = true;
-        waitUntil(flush(timeout));
+      if (!flushPromise && waitUntil) {
+        flushPromise = flush(timeout);
+        waitUntil(flushPromise);
       }
     };
 
@@ -155,9 +155,12 @@ export function wrapRequestHandler(
             })();
 
             // Use waitUntil to keep context alive and flush after span ends
-            if (waitUntil) {
-              flushScheduled = true;
-              waitUntil(streamMonitor.then(() => flush(2000)));
+            if (waitUntil && !flushPromise) {
+              flushPromise = streamMonitor.then(() => flush(2000));
+              waitUntil(flushPromise);
+            } else if (waitUntil && flushPromise) {
+              // Just wait for the stream to complete
+              waitUntil(streamMonitor);
             }
 
             // Return response with client stream