fix(pack): use short hashes for production client chunks

crates/pack-core/src/client/context.rs

@@ -17,8 +17,8 @@ use turbopack_browser::{BrowserChunkingContext, CurrentChunkMethod};
 use turbopack_core::{
     asset::AssetContent,
     chunk::{
-        ChunkingConfig, ChunkingContext, MangleType, MinifyType, SourceMapSourceType,
-        SourceMapsType, UnusedReferences, chunk_id_strategy::ModuleIdStrategy,
+        ChunkingConfig, ChunkingContext, ContentHashing, MangleType, MinifyType,
+        SourceMapSourceType, SourceMapsType, UnusedReferences, chunk_id_strategy::ModuleIdStrategy,
     },
     compile_time_info::{
         CompileTimeDefineValue, CompileTimeInfo, DefinableNameSegment, FreeVarReference,
@@ -779,6 +779,7 @@ pub async fn get_client_chunking_context(
                 Vc::<CssChunkType>::default().to_resolved().await?,
                 css_chunking_config,
             )
+            .chunk_content_hashing(ContentHashing::Direct { length: 13 })
             .module_merging(*scope_hoisting.await?);
     }
 

crates/pack-tests/tests/chunk_hashing.rs

@@ -0,0 +1,98 @@
+use anyhow::Result;
+use pack_core::mode::Mode;
+use turbo_rcstr::{RcStr, rcstr};
+use turbo_tasks::{ResolvedVc, TurboTasks, Vc};
+use turbo_tasks_backend::{BackendOptions, TurboTasksBackend, noop_backing_storage};
+use turbo_tasks_fs::{File, FileContent, FileSystem, VirtualFileSystem};
+use turbopack_browser::BrowserChunkingContext;
+use turbopack_core::{
+    asset::AssetContent,
+    chunk::{ChunkingContext, ContentHashing},
+    environment::{BrowserEnvironment, Environment, ExecutionEnvironment},
+    ident::AssetIdent,
+    virtual_output::VirtualOutputAsset,
+};
+
+async fn chunk_filename(salt: &str, length: u8, extension: &str) -> Result<String> {
+    let root = VirtualFileSystem::new_with_name(rcstr!("chunk-hashing"))
+        .root()
+        .owned()
+        .await?;
+    let environment = Environment::new(ExecutionEnvironment::Browser(
+        BrowserEnvironment {
+            dom: true,
+            web_worker: false,
+            service_worker: false,
+            browserslist_query: rcstr!("defaults"),
+        }
+        .cell()
+        .to_resolved()
+        .await?,
+    ))
+    .to_resolved()
+    .await?;
+    let context = BrowserChunkingContext::builder(
+        root.clone(),
+        root.clone(),
+        rcstr!(""),
+        root.clone(),
+        root.clone(),
+        root.clone(),
+        environment,
+        Mode::Production.runtime_type(),
+    )
+    .hash_salt(ResolvedVc::cell(RcStr::from(salt)))
+    .chunk_content_hashing(ContentHashing::Direct { length })
+    .build();
+    let path = root.join("input.js")?;
+    let content = AssetContent::file(FileContent::Content(File::from("/* chunk */")).cell())
+        .to_resolved()
+        .await?;
+    let asset = VirtualOutputAsset::new(path.clone(), *content);
+    let output = context
+        .chunk_path(
+            Some(Vc::upcast(asset)),
+            AssetIdent::from_path(path).into_vc(),
+            Some(rcstr!("worker")),
+            extension.into(),
+        )
+        .await?;
+    Ok(output.path.to_string())
+}
+
+#[tokio::test]
+async fn default_chunk_hash_respects_salt_and_length() -> Result<()> {
+    let tt = TurboTasks::new(TurboTasksBackend::new(
+        BackendOptions {
+            storage_mode: None,
+            ..Default::default()
+        },
+        noop_backing_storage(),
+    ));
+    tt.run_once(async {
+        check_chunk_hashing().read_strongly_consistent().await?;
+        Ok(())
+    })
+    .await
+}
+
+#[turbo_tasks::function(operation, root)]
+async fn check_chunk_hashing() -> Result<Vc<()>> {
+    for extension in [".js", ".css"] {
+        let unsalted = chunk_filename("", 13, extension).await?;
+        let salted = chunk_filename("release-a", 13, extension).await?;
+        assert_ne!(unsalted, salted, "salt must change the output filename");
+        assert_ne!(salted, chunk_filename("release-b", 13, extension).await?);
+        assert_eq!(salted, chunk_filename("release-a", 13, extension).await?);
+        assert!(salted.starts_with("worker-"));
+        assert!(salted.ends_with(extension));
+        assert_eq!(salted.len(), "worker-".len() + 13 + extension.len());
+
+        let full = chunk_filename("release-a", 25, extension).await?;
+        assert_eq!(full.len(), "worker-".len() + 25 + extension.len());
+        for length in [26, u8::MAX] {
+            assert_eq!(chunk_filename("release-a", length, extension).await?, full);
+        }
+    }
+    Ok(Vc::cell(()))
+}

crates/pack-tests/tests/snapshot/async_chunk/output/stats.json

@@ -3,15 +3,15 @@
     "main": {
       "name": "main",
       "chunks": [
-        "input_15liy8us72sxf.js",
-        "main.js"
+        "3iutdrd92konk.js",
+        "turbopack-42u84-9btqy5o.js"
       ],
       "assets": [
         {
-          "name": "input_15liy8us72sxf.js"
+          "name": "3iutdrd92konk.js"
         },
         {
-          "name": "main.js"
+          "name": "turbopack-42u84-9btqy5o.js"
         }
       ]
     }
@@ -22,109 +22,109 @@
       "initial": false,
       "entry": false,
       "recorded": false,
-      "id": "input_0g__tdm89q74f.js",
-      "size": 710,
+      "id": "1nqwnu9guu79c.js",
+      "size": 704,
       "hash": "",
       "files": [
-        "input_0g__tdm89q74f.js"
+        "1nqwnu9guu79c.js"
       ]
     },
     {
       "rendered": false,
       "initial": false,
       "entry": false,
       "recorded": false,
-      "id": "input_15liy8us72sxf.js",
-      "size": 891,
+      "id": "3iutdrd92konk.js",
+      "size": 879,
       "hash": "",
       "files": [
-        "input_15liy8us72sxf.js"
+        "3iutdrd92konk.js"
       ]
     },
     {
       "rendered": false,
       "initial": false,
       "entry": false,
       "recorded": false,
-      "id": "main.js",
-      "size": 264,
+      "id": "turbopack-42u84-9btqy5o.js",
+      "size": 258,
       "hash": "",
       "files": [
-        "main.js"
+        "turbopack-42u84-9btqy5o.js"
       ]
     }
   ],
   "assets": [
     {
       "type": "asset",
-      "name": "input_0g__tdm89q74f.js",
+      "name": "007_nutjpavf2.js.map",
       "info": {},
-      "size": 710,
+      "size": 798,
       "emitted": false,
       "comparedForEmit": false,
       "cached": false,
       "chunks": [
-        "input_0g__tdm89q74f.js"
+        "007_nutjpavf2.js.map"
       ]
     },
     {
       "type": "asset",
-      "name": "input_0g__tdm89q74f.js.map",
+      "name": "1nqwnu9guu79c.js",
       "info": {},
-      "size": 731,
+      "size": 704,
       "emitted": false,
       "comparedForEmit": false,
       "cached": false,
       "chunks": [
-        "input_0g__tdm89q74f.js.map"
+        "1nqwnu9guu79c.js"
       ]
     },
     {
       "type": "asset",
-      "name": "input_15liy8us72sxf.js",
+      "name": "2wq8h34u5n9pv.js.map",
       "info": {},
-      "size": 891,
+      "size": 731,
       "emitted": false,
       "comparedForEmit": false,
       "cached": false,
       "chunks": [
-        "input_15liy8us72sxf.js"
+        "2wq8h34u5n9pv.js.map"
       ]
     },
     {
       "type": "asset",
-      "name": "input_15liy8us72sxf.js.map",
+      "name": "2z3sh82dl8glu.js.map",
       "info": {},
-      "size": 798,
+      "size": 53,
       "emitted": false,
       "comparedForEmit": false,
       "cached": false,
       "chunks": [
-        "input_15liy8us72sxf.js.map"
+        "2z3sh82dl8glu.js.map"
       ]
     },
     {
       "type": "asset",
-      "name": "main.js",
+      "name": "3iutdrd92konk.js",
       "info": {},
-      "size": 264,
+      "size": 879,
       "emitted": false,
       "comparedForEmit": false,
       "cached": false,
       "chunks": [
-        "main.js"
+        "3iutdrd92konk.js"
       ]
     },
     {
       "type": "asset",
-      "name": "main.js.map",
+      "name": "turbopack-42u84-9btqy5o.js",
       "info": {},
-      "size": 53,
+      "size": 258,
       "emitted": false,
       "comparedForEmit": false,
       "cached": false,
       "chunks": [
-        "main.js.map"
+        "turbopack-42u84-9btqy5o.js"
       ]
     }
   ],
@@ -133,41 +133,41 @@
       "name": "async_chunk/input/node_modules/bar/index.js",
       "id": 2,
       "chunks": [
-        "input_15liy8us72sxf.js"
+        "3iutdrd92konk.js"
       ],
       "size": 152
     },
     {
       "name": "async_chunk/input/node_modules/foo/index.js",
       "id": 26,
       "chunks": [
-        "input_0g__tdm89q74f.js"
+        "1nqwnu9guu79c.js"
       ],
       "size": 152
     },
     {
       "name": "async_chunk/input/index.js",
       "id": 45,
       "chunks": [
-        "input_15liy8us72sxf.js"
+        "3iutdrd92konk.js"
       ],
       "size": 266
     },
     {
       "name": "async_chunk/input/import.js",
       "id": 76,
       "chunks": [
-        "input_0g__tdm89q74f.js"
+        "1nqwnu9guu79c.js"
       ],
       "size": 327
     },
     {
       "name": "async_chunk/input/import.js",
       "id": 92,
       "chunks": [
-        "input_15liy8us72sxf.js"
+        "3iutdrd92konk.js"
       ],
-      "size": 237
+      "size": 231
     }
   ]
 }

crates/pack-tests/tests/snapshot/async_chunk/output/main.js → crates/pack-tests/tests/snapshot/async_chunk/output/turbopack-42u84-9btqy5o.js

@@ -1,5 +1,5 @@
 (globalThis["utooChunk_async_chunk_test"] || (globalThis["utooChunk_async_chunk_test"] = [])).push([
     typeof document === "object" ? document.currentScript : undefined,
-    {"otherChunks":["input_15liy8us72sxf.js"],"runtimeModuleIds":[45]}
+    {"otherChunks":["3iutdrd92konk.js"],"runtimeModuleIds":[45]}
 ]);
 // Dummy runtime

crates/pack-tests/tests/snapshot/basic/alias/output/turbopack-22ecp8b-t377e.js

@@ -0,0 +1,5 @@
+(globalThis["TURBOPACK"] || (globalThis["TURBOPACK"] = [])).push([
+    typeof document === "object" ? document.currentScript : undefined,
+    {"otherChunks":["37o_c1e84go2i.js","3ifzw8uwk49rx.css"],"runtimeModuleIds":["[project]/basic/alias/input/index.ts [client] (ecmascript)"]}
+]);
+// Dummy runtime