[next] add .action handling for dynamic routes (#11461)

Follow-up to:
- https://github.com/vercel/vercel/pull/11454

Adds similar handling for dynamic routes

.changeset/cold-pianos-check.md

@@ -0,0 +1,5 @@
+---
+"@vercel/next": patch
+---
+
+[next] add .action handling for dynamic routes

packages/next/src/utils.ts

@@ -432,6 +432,15 @@ export async function getDynamicRoutes({
             dest: route.dest?.replace(/($|\?)/, '.rsc$1'),
           });
 
+          routes.push({
+            ...route,
+            src: route.src.replace(
+              new RegExp(escapeStringRegexp('(?:/)?$')),
+              '(?:\\.action)(?:/)?$'
+            ),
+            dest: route.dest?.replace(/($|\?)/, '.action$1'),
+          });
+
           routes.push(route);
         }
 

packages/next/test/fixtures/00-app-dir-actions/app/[dynamic-static]/page.js

@@ -0,0 +1,17 @@
+import { revalidatePath } from 'next/cache'
+
+export const dynamic = 'force-static'
+
+export default async function Page() {
+  async function serverAction() {
+    'use server';
+    await new Promise((resolve) => setTimeout(resolve, 1000));
+    revalidatePath('/dynamic');
+  }
+
+  return (
+    <form action={serverAction}>
+      <button>Submit</button>
+    </form>
+  );
+}

packages/next/test/fixtures/00-app-dir-actions/index.test.js

@@ -65,4 +65,25 @@ describe(`${__dirname.split(path.sep).pop()}`, () => {
     expect(res.headers.get('x-matched-path')).toBe('/other.action');
     expect(res.headers.get('x-vercel-cache')).toBe('MISS');
   });
+
+  it('should match the server action to the streaming prerender function (force-static dynamic segment)', async () => {
+    const data = await fetch(
+      `${ctx.deploymentUrl}/server-reference-manifest.json`
+    ).then(res => res.json());
+
+    const actionId = findActionId(data, 'app/dynamic-static/page');
+
+    const res = await fetch(`${ctx.deploymentUrl}/dynamic-static`, {
+      method: 'POST',
+      body: `------WebKitFormBoundary8xC9UKOVzHBaGYkR\r\nContent-Disposition: form-data; name=\"1_$ACTION_ID_${actionId}\"\r\n\r\n\r\n------WebKitFormBoundary8xC9UKOVzHBaGYkR\r\nContent-Disposition: form-data; name=\"0\"\r\n\r\n[\"$K1\"]\r\n------WebKitFormBoundary8xC9UKOVzHBaGYkR--\r\n`,
+      headers: {
+        'Content-Type':
+          'multipart/form-data; boundary=----WebKitFormBoundary8xC9UKOVzHBaGYkR',
+      },
+    });
+
+    expect(res.status).toEqual(200);
+    expect(res.headers.get('x-matched-path')).toBe('/[dynamic-static].action');
+    expect(res.headers.get('x-vercel-cache')).toBe('MISS');
+  });
 });