interception routes: fix rewrites order (#49615)

This PR fixes an issue where the rewrites were applied too early and
thus not working with other beforeFiles rewrites

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link NEXT-1148

Co-authored-by: JJ Kasper <jj@jjsweb.site>

packages/next/src/build/index.ts

@@ -557,7 +557,7 @@ export default async function build(
       }
 
       // Interception routes are modelled as beforeFiles rewrites
-      rewrites.beforeFiles.unshift(
+      rewrites.beforeFiles.push(
         ...generateInterceptionRoutesRewrites(appPageKeys)
       )
 

packages/next/src/server/dev/next-dev-server.ts

@@ -793,10 +793,12 @@ export default class DevServer extends Server {
           : undefined
 
         this.customRoutes = await loadCustomRoutes(this.nextConfig)
-        this.customRoutes.rewrites.beforeFiles.unshift(
+        const { rewrites } = this.customRoutes
+
+        this.customRoutes.rewrites.beforeFiles.push(
           ...generateInterceptionRoutesRewrites(Object.keys(appPaths))
         )
-        const { rewrites } = this.customRoutes
+
         if (
           rewrites.beforeFiles.length ||
           rewrites.afterFiles.length ||

test/e2e/app-dir/parallel-routes-and-interception/app/[lang]/foo/(..)photos/page.js

@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div id="intercepted">intercepted</div>
+}

test/e2e/app-dir/parallel-routes-and-interception/app/[lang]/foo/page.js

@@ -0,0 +1,12 @@
+'use client'
+
+import Link from 'next/link'
+
+export default function Page() {
+  return (
+    <div>
+      <div id="foo">FOO</div>
+      <Link href="/photos">To photos</Link>
+    </div>
+  )
+}

test/e2e/app-dir/parallel-routes-and-interception/app/[lang]/photos/page.js

@@ -0,0 +1,3 @@
+export default function Page() {
+  return 'non intercepted'
+}

test/e2e/app-dir/parallel-routes-and-interception/next.config.js

@@ -1,6 +1,21 @@
 /**
  * @type {import('next').NextConfig}
  */
-const nextConfig = {}
+const nextConfig = {
+  async rewrites() {
+    return {
+      beforeFiles: [
+        {
+          source: '/foo',
+          destination: '/en/foo',
+        },
+        {
+          source: '/photos',
+          destination: '/en/photos',
+        },
+      ],
+    }
+  },
+}
 
 module.exports = nextConfig

test/e2e/app-dir/parallel-routes-and-interception/parallel-routes-and-interception.test.ts

@@ -503,6 +503,20 @@ createNextDescribe(
           next.url + '/intercepting-parallel-modal/photo/2'
         )
       })
+
+      it('should support intercepting with beforeFiles rewrites', async () => {
+        const browser = await next.browser('/foo')
+
+        await check(
+          () =>
+            browser
+              .elementByCss('[href="/photos"]')
+              .click()
+              .waitForElementByCss('#intercepted')
+              .text(),
+          'intercepted'
+        )
+      })
     })
   }
 )