fix(e2e): Align middleware detection test cases for next@16 (#7047)

Author: panteliselef

integration/tests/middleware-placement.test.ts

@@ -1,9 +1,36 @@
 import { expect, test } from '@playwright/test';
+import path from 'path';
 
 import type { Application } from '../models/application';
+import { stateFile } from '../models/stateFile';
 import { appConfigs } from '../presets';
+import { fs } from '../scripts';
 import { createTestUtils } from '../testUtils';
 
+function parseSemverMajor(range?: string): number | undefined {
+  if (!range) {
+    return undefined;
+  }
+  const match = String(range).match(/\d+/);
+  return match ? Number.parseInt(match[0], 10) : undefined;
+}
+
+async function detectNext(app: Application): Promise<{ isNext: boolean; version?: string }> {
+  // app.appDir exists for normal Application; for long-running apps, read it from the state file by serverUrl
+  const appDir =
+    (app as any).appDir ||
+    Object.values(stateFile.getLongRunningApps() || {}).find(a => a.serverUrl === app.serverUrl)?.appDir;
+
+  if (!appDir) {
+    return { isNext: false };
+  }
+
+  const pkg = await fs.readJSON(path.join(appDir, 'package.json'));
+  const nextRange: string | undefined = pkg.dependencies?.next || pkg.devDependencies?.next;
+
+  return { isNext: Boolean(nextRange), version: nextRange };
+}
+
 const middlewareFileContents = `
 import { clerkMiddleware } from '@clerk/nextjs/server';
 export default clerkMiddleware();
@@ -61,6 +88,9 @@ test.describe('next start - invalid middleware at root on src/ @quickstart', ()
     page,
     context,
   }) => {
+    const { version } = await detectNext(app);
+    const major = parseSemverMajor(version) ?? 0;
+    test.skip(major >= 16, 'Middleware detection is smarter in Next 16+.');
     const u = createTestUtils({ app, page, context });
     await u.page.goToAppHome();
 
@@ -69,6 +99,15 @@ test.describe('next start - invalid middleware at root on src/ @quickstart', ()
       'Clerk: clerkMiddleware() was not run, your middleware file might be misplaced. Move your middleware file to ./src/middleware.ts. Currently located at ./middleware.ts',
     );
   });
+
+  test('Does not display misplaced middleware error on Next 16+', async ({ page, context }) => {
+    const { version } = await detectNext(app);
+    const major = parseSemverMajor(version) ?? 0;
+    test.skip(major < 16, 'Only applicable on Next 16+');
+    const u = createTestUtils({ app, page, context });
+    await u.page.goToAppHome();
+    expect(app.serveOutput).not.toContain('Clerk: clerkMiddleware() was not run');
+  });
 });
 
 test.describe('next start - invalid middleware inside app on src/ @quickstart', () => {