Add test for rewrite from pages to app with existing pages path (verc…

…el#41023)

Rather specific test for when you incrementally migrate using middleware and only route to the `app` route based on some condition.



## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have a helpful link attached, see `contributing.md`

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have a helpful link attached, see `contributing.md`

## Documentation / Examples

- [ ] Make sure the linting passes by running `pnpm lint`
- [ ] The "examples guidelines" are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)

test/e2e/app-dir/app/middleware.js

@@ -6,6 +6,10 @@ import { NextResponse } from 'next/server'
  * @returns {NextResponse | undefined}
  */
 export function middleware(request) {
+  if (request.nextUrl.pathname === '/exists-but-not-routed') {
+    return NextResponse.rewrite(new URL('/dashboard', request.url))
+  }
+
   if (request.nextUrl.pathname === '/middleware-to-dashboard') {
     return NextResponse.rewrite(new URL('/dashboard', request.url))
   }

test/e2e/app-dir/app/pages/exists-but-not-routed.js

@@ -0,0 +1,15 @@
+export async function getServerSideProps() {
+  return {
+    props: {
+      message: 'Hello World!',
+    },
+  }
+}
+
+export default function Page({ message }) {
+  return (
+    <>
+      <p>hello from exists but not routed {message}</p>
+    </>
+  )
+}

test/e2e/app-dir/app/pages/link-to-rewritten-path.js

@@ -0,0 +1,11 @@
+import Link from 'next/link'
+
+export default function Page(props) {
+  return (
+    <>
+      <Link href="/exists-but-not-routed">
+        <a id="link-to-rewritten-path">Exists but not routed</a>
+      </Link>
+    </>
+  )
+}

test/e2e/app-dir/index.test.ts

@@ -238,13 +238,34 @@ describe('app dir', () => {
     })
 
     describe('rewrites', () => {
-      // TODO-APP:
+      // TODO-APP: rewrite url is broken
       it.skip('should support rewrites on initial load', async () => {
         const browser = await webdriver(next.url, '/rewritten-to-dashboard')
         expect(await browser.elementByCss('h1').text()).toBe('Dashboard')
         expect(await browser.url()).toBe(`${next.url}/rewritten-to-dashboard`)
       })
 
+      it('should support rewrites on client-side navigation from pages to app with existing pages path', async () => {
+        const browser = await webdriver(next.url, '/link-to-rewritten-path')
+
+        try {
+          // Click the link.
+          await browser.elementById('link-to-rewritten-path').click()
+          await browser.waitForElementByCss('#from-dashboard')
+
+          // Check to see that we were rewritten and not redirected.
+          // TODO-APP: rewrite url is broken
+          // expect(await browser.url()).toBe(`${next.url}/rewritten-to-dashboard`)
+
+          // Check to see that the page we navigated to is in fact the dashboard.
+          expect(await browser.elementByCss('#from-dashboard').text()).toBe(
+            'hello from app/dashboard'
+          )
+        } finally {
+          await browser.close()
+        }
+      })
+
       it('should support rewrites on client-side navigation', async () => {
         const browser = await webdriver(next.url, '/rewrites')