fix: prevent submission endpoint hang on Cloudflare Workers (#141)

Replace the interactive transaction in formData.setFormData with a single atomic ctx.db.batch(). The interactive transaction issued four sequential network round-trips (BEGIN/INSERT/UPDATE/COMMIT) that held the libSQL write lock for their whole duration; under concurrent submissions they serialized on the lock and blew the Worker execution budget, so workerd canceled the request as hung. batch() runs both writes in one round-trip inside an implicit backend transaction, preserving all-or-nothing atomicity (the FK-failure rollback test stays green).

Defer the notification email with Next's after() instead of a floating promise. I/O started by a promise that outlives the response is invalid on Workers, so notification emails silently failed; after() runs it in a valid post-response context (OpenNext maps it to waitUntil) and a .catch() keeps a failed email from escalating to a request exception.

Author: ephraimduncan

apps/web/src/app/api/s/[id]/route.ts

@@ -1,4 +1,4 @@
-import { userAgent } from 'next/server';
+import { after, userAgent } from 'next/server';
 
 import { type RouterOutputs } from '@formbase/api';
 
@@ -142,7 +142,11 @@ export async function POST(
     });
 
     if (!spamResult.isSpam) {
-      void handleEmailNotifications(form, cleanedFormData);
+      after(() =>
+        handleEmailNotifications(form, cleanedFormData).catch((error) => {
+          console.error('Failed to send submission notification email', error);
+        }),
+      );
     }
     const { browser } = userAgent(request);
 

packages/api/routers/formData.ts

@@ -120,26 +120,25 @@ export const formDataRouter = createTRPCRouter({
       }),
     )
     .mutation(async ({ ctx, input }) => {
-      return await ctx.db.transaction(async (tx) => {
-        const formdata = await tx.insert(formDatas).values({
+      const [formdata] = await ctx.db.batch([
+        ctx.db.insert(formDatas).values({
           data: serializeJson(input.data),
           formId: input.formId,
           id: generateId(15),
           createdAt: new Date(),
           isSpam: input.isSpam,
           spamReason: input.spamReason ?? null,
-        });
-
-        await tx
+        }),
+        ctx.db
           .update(forms)
           .set({
             updatedAt: new Date(),
             keys: serializeJson(input.keys),
           })
-          .where(eq(forms.id, input.formId));
+          .where(eq(forms.id, input.formId)),
+      ]);
 
-        return formdata;
-      });
+      return formdata;
     }),
 
   markAsSpam: protectedProcedure