fix router prefetch cache key to work with route interception

packages/next/src/client/components/router-reducer/reducers/create-prefetch-cache-key.ts

@@ -0,0 +1,26 @@
+import { addPathPrefix } from '../../../../shared/lib/router/utils/add-path-prefix'
+import { pathHasPrefix } from '../../../../shared/lib/router/utils/path-has-prefix'
+import { createHrefFromUrl } from '../create-href-from-url'
+
+/**
+ * Creates a cache key for the router prefetch cache
+ *
+ * @param url - The URL being navigated to
+ * @param nextUrl - an internal URL, primarily used for handling rewrites. Defaults to '/'.
+ * @return The generated prefetch cache key.
+ */
+export function createPrefetchCacheKey(url: URL, nextUrl: string | null) {
+  const pathnameFromUrl = createHrefFromUrl(
+    url,
+    // Ensures the hash is not part of the cache key as it does not impact the server fetch
+    false
+  )
+
+  // Route interception depends on `nextUrl` values which aren't a 1:1 mapping to a URL
+  // The cache key that we store needs to use `nextUrl` to properly distinguish cache entries
+  if (nextUrl && !pathHasPrefix(pathnameFromUrl, nextUrl)) {
+    return addPathPrefix(nextUrl, pathnameFromUrl)
+  }
+
+  return pathnameFromUrl
+}

packages/next/src/client/components/router-reducer/reducers/navigate-reducer.ts

@@ -32,6 +32,7 @@ import {
   listenForDynamicRequest,
   updateCacheNodeOnNavigation,
 } from '../ppr-navigations'
+import { createPrefetchCacheKey } from './create-prefetch-cache-key'
 
 export function handleExternalUrl(
   state: ReadonlyReducerState,
@@ -126,7 +127,8 @@ function navigateReducer_noPPR(
     return handleExternalUrl(state, mutable, url.toString(), pendingPush)
   }
 
-  let prefetchValues = state.prefetchCache.get(createHrefFromUrl(url, false))
+  const prefetchCacheKey = createPrefetchCacheKey(url, state.nextUrl)
+  let prefetchValues = state.prefetchCache.get(prefetchCacheKey)
 
   // If we don't have a prefetch value, we need to create one
   if (!prefetchValues) {
@@ -152,7 +154,7 @@ function navigateReducer_noPPR(
       lastUsedTime: null,
     }
 
-    state.prefetchCache.set(createHrefFromUrl(url, false), newPrefetchValue)
+    state.prefetchCache.set(prefetchCacheKey, newPrefetchValue)
     prefetchValues = newPrefetchValue
   }
 
@@ -320,7 +322,8 @@ function navigateReducer_PPR(
     return handleExternalUrl(state, mutable, url.toString(), pendingPush)
   }
 
-  let prefetchValues = state.prefetchCache.get(createHrefFromUrl(url, false))
+  const prefetchCacheKey = createPrefetchCacheKey(url, state.nextUrl)
+  let prefetchValues = state.prefetchCache.get(prefetchCacheKey)
 
   // If we don't have a prefetch value, we need to create one
   if (!prefetchValues) {
@@ -346,7 +349,7 @@ function navigateReducer_PPR(
       lastUsedTime: null,
     }
 
-    state.prefetchCache.set(createHrefFromUrl(url, false), newPrefetchValue)
+    state.prefetchCache.set(prefetchCacheKey, newPrefetchValue)
     prefetchValues = newPrefetchValue
   }
 

packages/next/src/client/components/router-reducer/reducers/prefetch-reducer.ts

@@ -1,4 +1,3 @@
-import { createHrefFromUrl } from '../create-href-from-url'
 import { fetchServerResponse } from '../fetch-server-response'
 import type {
   PrefetchAction,
@@ -9,6 +8,7 @@ import { PrefetchKind } from '../router-reducer-types'
 import { prunePrefetchCache } from './prune-prefetch-cache'
 import { NEXT_RSC_UNION_QUERY } from '../../app-router-headers'
 import { PromiseQueue } from '../../promise-queue'
+import { createPrefetchCacheKey } from './create-prefetch-cache-key'
 
 export const prefetchQueue = new PromiseQueue(5)
 
@@ -22,20 +22,16 @@ export function prefetchReducer(
   const { url } = action
   url.searchParams.delete(NEXT_RSC_UNION_QUERY)
 
-  const href = createHrefFromUrl(
-    url,
-    // Ensures the hash is not part of the cache key as it does not affect fetching the server
-    false
-  )
+  const prefetchCacheKey = createPrefetchCacheKey(url, state.nextUrl)
+  const cacheEntry = state.prefetchCache.get(prefetchCacheKey)
 
-  const cacheEntry = state.prefetchCache.get(href)
   if (cacheEntry) {
     /**
      * If the cache entry present was marked as temporary, it means that we prefetched it from the navigate reducer,
      * where we didn't have the prefetch intent. We want to update it to the new, more accurate, kind here.
      */
     if (cacheEntry.kind === PrefetchKind.TEMPORARY) {
-      state.prefetchCache.set(href, {
+      state.prefetchCache.set(prefetchCacheKey, {
         ...cacheEntry,
         kind: action.kind,
       })
@@ -68,7 +64,7 @@ export function prefetchReducer(
   )
 
   // Create new tree based on the flightSegmentPath and router state patch
-  state.prefetchCache.set(href, {
+  state.prefetchCache.set(prefetchCacheKey, {
     // Create new tree based on the flightSegmentPath and router state patch
     treeAtTimeOfPrefetch: state.tree,
     data: serverResponse,

test/e2e/app-dir/interception-route-prefetch-cache/app/Modal.tsx

@@ -0,0 +1,27 @@
+'use client'
+
+import { useRouter } from 'next/navigation'
+
+interface ModalProps {
+  title: string
+  context: string
+}
+
+export function Modal({ title, context }: ModalProps) {
+  const router = useRouter()
+
+  return (
+    <div>
+      <div className="modal">
+        <h1>{title}</h1>
+        <h2>{context}</h2>
+      </div>
+      <div
+        className="modal-overlay"
+        onClick={() => {
+          router.back()
+        }}
+      />
+    </div>
+  )
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/bar/@modal/(...)post/[id]/page.tsx

@@ -0,0 +1,11 @@
+import { Modal } from '../../../../Modal'
+
+export default function BarPagePostInterceptSlot({
+  params: { id },
+}: {
+  params: {
+    id: string
+  }
+}) {
+  return <Modal title={`Post ${id}`} context="Intercepted on Bar Page" />
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/bar/@modal/default.tsx

@@ -0,0 +1,3 @@
+export default function Default() {
+  return null
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/bar/default.tsx

@@ -0,0 +1,3 @@
+export default function Default() {
+  return null
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/bar/layout.tsx

@@ -0,0 +1,14 @@
+export default function BarLayout({
+  modal,
+  children,
+}: {
+  modal: React.ReactNode
+  children: React.ReactNode
+}) {
+  return (
+    <>
+      <div id="slot">{modal}</div>
+      <div id="children">{children}</div>
+    </>
+  )
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/bar/page.tsx

@@ -0,0 +1,10 @@
+import Link from 'next/link'
+
+export default function BarPage() {
+  return (
+    <div>
+      <h1>Bar Page</h1>
+      <Link href="/post/1">Post 1</Link>
+    </div>
+  )
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/foo/@modal/(...)post/[id]/page.tsx

@@ -0,0 +1,11 @@
+import { Modal } from '../../../../Modal'
+
+export default function FooPagePostInterceptSlot({
+  params: { id },
+}: {
+  params: {
+    id: string
+  }
+}) {
+  return <Modal title={`Post ${id}`} context="Intercepted on Foo Page" />
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/foo/@modal/default.tsx

@@ -0,0 +1,3 @@
+export default function Default() {
+  return null
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/foo/default.tsx

@@ -0,0 +1,3 @@
+export default function Default() {
+  return null
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/foo/layout.tsx

@@ -0,0 +1,14 @@
+export default function FooLayout({
+  modal,
+  children,
+}: {
+  modal: React.ReactNode
+  children: React.ReactNode
+}) {
+  return (
+    <>
+      <div id="slot">{modal}</div>
+      <div id="children">{children}</div>
+    </>
+  )
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/foo/page.tsx

@@ -0,0 +1,10 @@
+import Link from 'next/link'
+
+export default function FooPage() {
+  return (
+    <div>
+      <h1>Foo Page</h1>
+      <Link href="/post/1">Post 1</Link>
+    </div>
+  )
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/layout.tsx

@@ -0,0 +1,13 @@
+import Link from 'next/link'
+
+export default function RootLayout({ children }) {
+  return (
+    <html>
+      <head />
+      <body>
+        <Link href="/">home</Link>
+        {children}
+      </body>
+    </html>
+  )
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/page.tsx

@@ -0,0 +1,18 @@
+import Link from 'next/link'
+
+export default function Home() {
+  return (
+    <ul>
+      <li>
+        <Link href="/foo">foo</Link>
+      </li>
+      <li>
+        <Link href="/bar">bar</Link>
+      </li>
+      <br />
+      <li>
+        <Link href="/post/1">post 1</Link>
+      </li>
+    </ul>
+  )
+}

test/e2e/app-dir/interception-route-prefetch-cache/app/post/[id]/page.tsx

@@ -0,0 +1,13 @@
+export default function PostPage({
+  params: { id },
+}: {
+  params: {
+    id: string
+  }
+}) {
+  return (
+    <div>
+      <h1>Post {id}</h1>
+    </div>
+  )
+}

test/e2e/app-dir/interception-route-prefetch-cache/interception-route-prefetch-cache.test.ts

@@ -0,0 +1,45 @@
+import { createNextDescribe } from 'e2e-utils'
+import { check } from 'next-test-utils'
+
+createNextDescribe(
+  'interception-route-prefetch-cache',
+  {
+    files: __dirname,
+  },
+  ({ next }) => {
+    it('should render the correct interception when two distinct layouts share the same path structure', async () => {
+      const browser = await next.browser('/')
+
+      await browser.elementByCss('[href="/foo"]').click()
+
+      await check(() => browser.elementById('children').text(), /Foo Page/)
+
+      await browser.elementByCss('[href="/post/1"]').click()
+
+      // Ensure the existing page content is still the same
+      await check(() => browser.elementById('children').text(), /Foo Page/)
+
+      // Verify we got the right interception
+      await check(
+        () => browser.elementById('slot').text(),
+        /Intercepted on Foo Page/
+      )
+
+      // Go back home. At this point, the router cache should have content from /foo
+      // Now we want to ensure that /bar doesn't share that same prefetch cache entry
+      await browser.elementByCss('[href="/"]').click()
+      await browser.elementByCss('[href="/bar"]').click()
+
+      await check(() => browser.elementById('children').text(), /Bar Page/)
+      await browser.elementByCss('[href="/post/1"]').click()
+
+      // Ensure the existing page content is still the same. If the prefetch cache resolved the wrong cache node
+      // then we'd see the content from /foo
+      await check(() => browser.elementById('children').text(), /Bar Page/)
+      await check(
+        () => browser.elementById('slot').text(),
+        /Intercepted on Bar Page/
+      )
+    })
+  }
+)