fix(metadata): align metadata suffix hash between turbopack

packages/next-swc/crates/next-core/src/next_app/metadata/mod.rs

@@ -258,7 +258,7 @@ fn djb2_hash(str: &str) -> u32 {
     })
 }
 
-// this is here to mirror next.js behaviour.
+// this is here to mirror next.js behaviour (`toString(36).slice(0, 6)`)
 fn format_radix(mut x: u32, radix: u32) -> String {
     let mut result = vec![];
 
@@ -273,7 +273,8 @@ fn format_radix(mut x: u32, radix: u32) -> String {
         }
     }
 
-    result.into_iter().rev().collect()
+    result.reverse();
+    result[..6].iter().collect()
 }
 
 /// If there's special convention like (...) or @ in the page path,

packages/next/src/shared/lib/hash.ts

@@ -1,11 +1,17 @@
 // http://www.cse.yorku.ca/~oz/hash.html
+// More specifically, 32-bit hash via djbxor
+// (ref: https://gist.github.com/eplawless/52813b1d8ad9af510d85?permalink_comment_id=3367765#gistcomment-3367765)
+// This is due to number type differences between rust for turbopack to js number types,
+// where rust does not have easy way to repreesnt js's 53-bit float number type for the matching
+// overflow behavior. This is more `correct` in terms of having canonical hash across different runtime / implementation
+// as can gaurantee determinstic output from 32bit hash.
 export function djb2Hash(str: string) {
   let hash = 5381
   for (let i = 0; i < str.length; i++) {
     const char = str.charCodeAt(i)
-    hash = (hash << 5) + hash + char
+    hash = ((hash << 5) + hash + char) & 0xffffffff
   }
-  return Math.abs(hash)
+  return hash >>> 0
 }
 
 export function hexHash(str: string) {

test/e2e/app-dir/metadata-dynamic-routes/index.test.ts

@@ -8,7 +8,7 @@ const CACHE_HEADERS = {
   REVALIDATE: 'public, max-age=0, must-revalidate',
 }
 
-const hashRegex = /\?\w+$/
+const hashRegex = /\?\w+/
 
 createNextDescribe(
   'app dir - metadata dynamic routes',
@@ -160,12 +160,12 @@ createNextDescribe(
         // slug is id param from generateImageMetadata
         expect(iconUrls).toMatchObject([
           {
-            href: '/dynamic/big/icon-48jo90/small',
+            href: '/dynamic/big/icon-ahg52g/small',
             sizes: '48x48',
             type: 'image/png',
           },
           {
-            href: '/dynamic/big/icon-48jo90/medium',
+            href: '/dynamic/big/icon-ahg52g/medium',
             sizes: '72x72',
             type: 'image/png',
           },
@@ -183,12 +183,12 @@ createNextDescribe(
         // slug is index by default
         expect(appleTouchIconUrls).toEqual([
           {
-            href: '/dynamic/big/apple-icon-48jo90/0',
+            href: '/dynamic/big/apple-icon-ahg52g/0',
             sizes: '48x48',
             type: 'image/png',
           },
           {
-            href: '/dynamic/big/apple-icon-48jo90/1',
+            href: '/dynamic/big/apple-icon-ahg52g/1',
             sizes: '64x64',
             type: 'image/png',
           },

test/turbopack-tests-manifest.json

@@ -3313,13 +3313,13 @@
       "app dir - metadata dynamic routes social image routes should support generate multi sitemaps with generateSitemaps",
       "app dir - metadata dynamic routes text routes should handle robots.[ext] dynamic routes",
       "app dir - metadata dynamic routes text routes should handle sitemap.[ext] dynamic routes",
-      "app dir - metadata dynamic routes text routes should not throw if client components are imported but not used"
+      "app dir - metadata dynamic routes text routes should not throw if client components are imported but not used",
+      "app dir - metadata dynamic routes social image routes should fill params into routes groups url of static images",
+      "app dir - metadata dynamic routes social image routes should support params as argument in dynamic routes",
+      "app dir - metadata dynamic routes should generate unique path for image routes under group routes"
     ],
     "failed": [
-      "app dir - metadata dynamic routes should generate unique path for image routes under group routes",
-      "app dir - metadata dynamic routes social image routes should fill params into routes groups url of static images",
-      "app dir - metadata dynamic routes social image routes should handle custom fonts in both edge and nodejs runtime",
-      "app dir - metadata dynamic routes social image routes should support params as argument in dynamic routes"
+      "app dir - metadata dynamic routes social image routes should handle custom fonts in both edge and nodejs runtime"
     ],
     "pending": [],
     "flakey": [],