fix(wh): immediately flush if overflow

src/v1/merger.ts

@@ -33,15 +33,27 @@ export function webhookMerger(app: App) {
 
         const oldData = existing.data;
         const flushed = new Set<string>();
-        existing.data = merge(
+        const merged = merge(
           oldData,
           body,
           undefined,
           MAX_FIELD_LENGTH,
           flushed,
         );
+        existing.data = merged;
         existing.count++;
 
+        if (JSON.stringify(merged).length > 2000) {
+          existing.data = body;
+          existing.count = 1;
+          forward(id, url, oldData);
+          existing.timer = setTimeout(
+            () => forward(id, url, existing.data),
+            bufferTime,
+          );
+          return status(202);
+        }
+
         if (flushed.size > 0) {
           existing.count = 1;
           forward(id, url, oldData);