From 2875f9944acd574631a2868bb0c8b48df9cd2494 Mon Sep 17 00:00:00 2001
From: Benjamin Woodruff <benjamin.woodruff@vercel.com>
Date: Tue, 30 Apr 2024 20:05:02 -0700
Subject: [PATCH 1/4] Emit polyfill-nomodule.js into the build manifest
 polyfillFiles

- `polyfill-nomodule.js` is a pre-built file containing polyfills for
  older browsers (gated by the `<script>` tag `nomodule` attribute).
- The turbopack server needs to emit a raw OutputAsset for this file, so
  that it is copied into the output chunks directory.
- That file needs to be passed into `polyfillFiles`, and preserved when
  we're merging manifests inside of the development server.
---
 packages/next-swc/crates/next-api/src/app.rs  | 25 ++++++++++++++++
 .../server/dev/turbopack/manifest-loader.ts   | 30 +++++++++++--------
 2 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/packages/next-swc/crates/next-api/src/app.rs b/packages/next-swc/crates/next-api/src/app.rs
index 1fda6368d3aed..1e2d6b2610686 100644
--- a/packages/next-swc/crates/next-api/src/app.rs
+++ b/packages/next-swc/crates/next-api/src/app.rs
@@ -49,6 +49,8 @@ use turbopack_binding::{
             file_source::FileSource,
             module::Module,
             output::{OutputAsset, OutputAssets},
+            reference_type::{CommonJsReferenceSubType, ReferenceType},
+            resolve::{node::node_cjs_resolve_options, parse::Request, resolve},
             virtual_output::VirtualOutputAsset,
         },
         nodejs::EntryChunkGroupResult,
@@ -894,8 +896,31 @@ impl AppEndpoint {
             ));
             server_assets.push(app_build_manifest_output);
 
+            const POLYFILL_PATH: &str = "next/dist/build/polyfills/polyfill-nomodule.js";
+            let project_path = this.app_project.project().project_path();
+            let polyfill_path = resolve(
+                project_path,
+                Value::new(ReferenceType::CommonJs(CommonJsReferenceSubType::Undefined)),
+                Request::parse_string(POLYFILL_PATH.to_string()),
+                node_cjs_resolve_options(project_path),
+            )
+            .as_raw_module_result()
+            .primary_output_assets()
+            .await?
+            .first()
+            .with_context(|| format!("failed to resolve {POLYFILL_PATH}"))?
+            .ident()
+            .await?
+            .path
+            .await?;
+            let polyfill_path = client_relative_path_ref
+                .get_path_to(&polyfill_path)
+                .context("failed to resolve client-relative path to polyfill")?;
+            let polyfill_paths = vec![polyfill_path.to_string()];
+
             let build_manifest = BuildManifest {
                 root_main_files: client_shared_chunks_paths,
+                polyfill_files: polyfill_paths,
                 ..Default::default()
             };
             let build_manifest_output = Vc::upcast(VirtualOutputAsset::new(
diff --git a/packages/next/src/server/dev/turbopack/manifest-loader.ts b/packages/next/src/server/dev/turbopack/manifest-loader.ts
index c796aedc1e132..247830c7df7b8 100644
--- a/packages/next/src/server/dev/turbopack/manifest-loader.ts
+++ b/packages/next/src/server/dev/turbopack/manifest-loader.ts
@@ -268,27 +268,33 @@ export class TurbopackManifestLoader {
     )
   }
 
-  private mergeBuildManifests(manifests: Iterable<BuildManifest>) {
-    const manifest: Partial<BuildManifest> & Pick<BuildManifest, 'pages'> = {
-      pages: {
-        '/_app': [],
-      },
+  private mergeBuildManifests(
+    manifests: Iterable<BuildManifest>
+  ): Partial<BuildManifest> & Pick<BuildManifest, 'pages'> {
+    const polyfillFiles: string[] = []
+    const pages = {
+      '/_app': [],
+    }
+    let rootMainFiles: readonly string[] = []
+    for (const m of manifests) {
+      Object.assign(pages, m.pages)
+      if (m.rootMainFiles.length) rootMainFiles = m.rootMainFiles
+      polyfillFiles.push(...m.polyfillFiles)
+    }
+
+    return {
+      pages,
       // Something in next.js depends on these to exist even for app dir rendering
       devFiles: [],
       ampDevFiles: [],
-      polyfillFiles: [],
+      polyfillFiles,
       lowPriorityFiles: [
         'static/development/_ssgManifest.js',
         'static/development/_buildManifest.js',
       ],
-      rootMainFiles: [],
+      rootMainFiles,
       ampFirstPages: [],
     }
-    for (const m of manifests) {
-      Object.assign(manifest.pages, m.pages)
-      if (m.rootMainFiles.length) manifest.rootMainFiles = m.rootMainFiles
-    }
-    return manifest
   }
 
   private async writeBuildManifest(

From 70fe677082d6ad70d79f3b97c1670d3ca7540eaf Mon Sep 17 00:00:00 2001
From: Benjamin Woodruff <benjamin.woodruff@vercel.com>
Date: Wed, 1 May 2024 22:40:53 -0700
Subject: [PATCH 2/4] Actually fix the thing by following sokra's comments!

---
 packages/next-swc/crates/next-api/src/app.rs  | 50 +++++++++----------
 packages/next-swc/crates/next-core/src/lib.rs |  1 +
 .../server/dev/turbopack/manifest-loader.ts   | 32 ++++++------
 3 files changed, 39 insertions(+), 44 deletions(-)

diff --git a/packages/next-swc/crates/next-api/src/app.rs b/packages/next-swc/crates/next-api/src/app.rs
index 1e2d6b2610686..4396c0d9096fc 100644
--- a/packages/next-swc/crates/next-api/src/app.rs
+++ b/packages/next-swc/crates/next-api/src/app.rs
@@ -7,7 +7,7 @@ use next_core::{
         get_entrypoints, Entrypoint as AppEntrypoint, Entrypoints as AppEntrypoints, LoaderTree,
         MetadataItem,
     },
-    get_edge_resolve_options_context,
+    get_edge_resolve_options_context, get_next_package,
     next_app::{
         app_client_references_chunks::get_app_server_reference_modules,
         get_app_client_references_chunks, get_app_client_shared_chunk_group, get_app_page_entry,
@@ -45,12 +45,15 @@ use turbopack_binding::{
     turbopack::{
         core::{
             asset::{Asset, AssetContent},
-            chunk::{availability_info::AvailabilityInfo, ChunkingContextExt, EvaluatableAssets},
+            chunk::{
+                availability_info::AvailabilityInfo, ChunkingContext, ChunkingContextExt,
+                EvaluatableAssets,
+            },
             file_source::FileSource,
             module::Module,
             output::{OutputAsset, OutputAssets},
-            reference_type::{CommonJsReferenceSubType, ReferenceType},
-            resolve::{node::node_cjs_resolve_options, parse::Request, resolve},
+            raw_module::RawModule,
+            resolve::{node::node_cjs_resolve_options, parse::Request},
             virtual_output::VirtualOutputAsset,
         },
         nodejs::EntryChunkGroupResult,
@@ -896,31 +899,26 @@ impl AppEndpoint {
             ));
             server_assets.push(app_build_manifest_output);
 
-            const POLYFILL_PATH: &str = "next/dist/build/polyfills/polyfill-nomodule.js";
-            let project_path = this.app_project.project().project_path();
-            let polyfill_path = resolve(
-                project_path,
-                Value::new(ReferenceType::CommonJs(CommonJsReferenceSubType::Undefined)),
-                Request::parse_string(POLYFILL_PATH.to_string()),
-                node_cjs_resolve_options(project_path),
-            )
-            .as_raw_module_result()
-            .primary_output_assets()
-            .await?
-            .first()
-            .with_context(|| format!("failed to resolve {POLYFILL_PATH}"))?
-            .ident()
-            .await?
-            .path
-            .await?;
-            let polyfill_path = client_relative_path_ref
-                .get_path_to(&polyfill_path)
-                .context("failed to resolve client-relative path to polyfill")?;
-            let polyfill_paths = vec![polyfill_path.to_string()];
+            // polyfill-nomodule.js is a pre-compiled asset distributed as part of next,
+            // load it as a RawModule.
+            let next_package = get_next_package(this.app_project.project().project_path());
+            let polyfill_source_path =
+                next_package.join("dist/build/polyfills/polyfill-nomodule.js".to_string());
+            let polyfill_module = RawModule::new(Vc::upcast(FileSource::new(polyfill_source_path)));
+            let polyfill_output_path =
+                client_chunking_context.chunk_path(polyfill_module.ident(), ".js".to_string());
+            let polyfill_output_asset =
+                VirtualOutputAsset::new(polyfill_output_path, polyfill_module.content());
+            let polyfill_client_path = client_relative_path_ref
+                .get_path_to(&*polyfill_output_path.await?)
+                .context("failed to resolve client-relative path to polyfill")?
+                .to_string();
+            let polyfill_client_paths = vec![polyfill_client_path];
+            client_assets.push(Vc::upcast(polyfill_output_asset));
 
             let build_manifest = BuildManifest {
                 root_main_files: client_shared_chunks_paths,
-                polyfill_files: polyfill_paths,
+                polyfill_files: polyfill_client_paths,
                 ..Default::default()
             };
             let build_manifest_output = Vc::upcast(VirtualOutputAsset::new(
diff --git a/packages/next-swc/crates/next-core/src/lib.rs b/packages/next-swc/crates/next-core/src/lib.rs
index ccf66bb91658c..6c28c7b956644 100644
--- a/packages/next-swc/crates/next-core/src/lib.rs
+++ b/packages/next-swc/crates/next-core/src/lib.rs
@@ -45,6 +45,7 @@ pub use next_edge::context::{
     get_edge_chunking_context, get_edge_chunking_context_with_client_assets,
     get_edge_compile_time_info, get_edge_resolve_options_context,
 };
+pub use next_import_map::get_next_package;
 pub use page_loader::{create_page_loader_entry_module, PageLoaderAsset};
 use turbopack_binding::{turbo, turbopack};
 pub use util::{get_asset_path_from_pathname, pathname_for_path, PathType};
diff --git a/packages/next/src/server/dev/turbopack/manifest-loader.ts b/packages/next/src/server/dev/turbopack/manifest-loader.ts
index 247830c7df7b8..0b42016baf160 100644
--- a/packages/next/src/server/dev/turbopack/manifest-loader.ts
+++ b/packages/next/src/server/dev/turbopack/manifest-loader.ts
@@ -268,33 +268,29 @@ export class TurbopackManifestLoader {
     )
   }
 
-  private mergeBuildManifests(
-    manifests: Iterable<BuildManifest>
-  ): Partial<BuildManifest> & Pick<BuildManifest, 'pages'> {
-    const polyfillFiles: string[] = []
-    const pages = {
-      '/_app': [],
-    }
-    let rootMainFiles: readonly string[] = []
-    for (const m of manifests) {
-      Object.assign(pages, m.pages)
-      if (m.rootMainFiles.length) rootMainFiles = m.rootMainFiles
-      polyfillFiles.push(...m.polyfillFiles)
-    }
-
-    return {
-      pages,
+  private mergeBuildManifests(manifests: Iterable<BuildManifest>) {
+    const manifest: Partial<BuildManifest> & Pick<BuildManifest, 'pages'> = {
+      pages: {
+        '/_app': [],
+      },
       // Something in next.js depends on these to exist even for app dir rendering
       devFiles: [],
       ampDevFiles: [],
-      polyfillFiles,
+      polyfillFiles: [],
       lowPriorityFiles: [
         'static/development/_ssgManifest.js',
         'static/development/_buildManifest.js',
       ],
-      rootMainFiles,
+      rootMainFiles: [],
       ampFirstPages: [],
     }
+    for (const m of manifests) {
+      Object.assign(manifest.pages, m.pages)
+      if (m.rootMainFiles.length) manifest.rootMainFiles = m.rootMainFiles
+      // polyfillFiles should always be the same, so we can overwrite instead of actually merging
+      if (m.polyfillFiles.length) manifest.polyfillFiles = m.polyfillFiles
+    }
+    return manifest
   }
 
   private async writeBuildManifest(

From dc462aa1f6a9baa10531e97601ddb5ab652be422 Mon Sep 17 00:00:00 2001
From: Benjamin Woodruff <benjamin.woodruff@vercel.com>
Date: Thu, 2 May 2024 14:56:33 -0700
Subject: [PATCH 3/4] Remove the unnecessary intermediate RawModule

---
 packages/next-swc/crates/next-api/src/app.rs | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/packages/next-swc/crates/next-api/src/app.rs b/packages/next-swc/crates/next-api/src/app.rs
index 4396c0d9096fc..fd42d04fe7fa7 100644
--- a/packages/next-swc/crates/next-api/src/app.rs
+++ b/packages/next-swc/crates/next-api/src/app.rs
@@ -52,8 +52,7 @@ use turbopack_binding::{
             file_source::FileSource,
             module::Module,
             output::{OutputAsset, OutputAssets},
-            raw_module::RawModule,
-            resolve::{node::node_cjs_resolve_options, parse::Request},
+            source::Source,
             virtual_output::VirtualOutputAsset,
         },
         nodejs::EntryChunkGroupResult,
@@ -902,13 +901,13 @@ impl AppEndpoint {
             // polyfill-nomodule.js is a pre-compiled asset distributed as part of next,
             // load it as a RawModule.
             let next_package = get_next_package(this.app_project.project().project_path());
-            let polyfill_source_path =
-                next_package.join("dist/build/polyfills/polyfill-nomodule.js".to_string());
-            let polyfill_module = RawModule::new(Vc::upcast(FileSource::new(polyfill_source_path)));
+            let polyfill_source = FileSource::new(
+                next_package.join("dist/build/polyfills/polyfill-nomodule.js".to_string()),
+            );
             let polyfill_output_path =
-                client_chunking_context.chunk_path(polyfill_module.ident(), ".js".to_string());
+                client_chunking_context.chunk_path(polyfill_source.ident(), ".js".to_string());
             let polyfill_output_asset =
-                VirtualOutputAsset::new(polyfill_output_path, polyfill_module.content());
+                VirtualOutputAsset::new(polyfill_output_path, polyfill_source.content());
             let polyfill_client_path = client_relative_path_ref
                 .get_path_to(&*polyfill_output_path.await?)
                 .context("failed to resolve client-relative path to polyfill")?

From ecc68cc5a88e3288ce174463dd6f6c5778bb06f9 Mon Sep 17 00:00:00 2001
From: Benjamin Woodruff <benjamin.woodruff@vercel.com>
Date: Thu, 2 May 2024 15:11:26 -0700
Subject: [PATCH 4/4] Update unit test to support turbo's different file path

---
 test/e2e/app-dir/app/index.test.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/test/e2e/app-dir/app/index.test.ts b/test/e2e/app-dir/app/index.test.ts
index 91b80235b82ac..8e695a09b447c 100644
--- a/test/e2e/app-dir/app/index.test.ts
+++ b/test/e2e/app-dir/app/index.test.ts
@@ -376,7 +376,9 @@ describe('app dir - basic', () => {
     it('should serve polyfills for browsers that do not support modules', async () => {
       const html = await next.render('/dashboard/index')
       expect(html).toMatch(
-        /<script src="\/_next\/static\/chunks\/polyfills(-\w+)?\.js" noModule="">/
+        isTurbopack
+          ? /<script src="\/_next\/static\/chunks\/[\w-]*polyfill-nomodule\.js" noModule="">/
+          : /<script src="\/_next\/static\/chunks\/polyfills(-\w+)?\.js" noModule="">/
       )
     })
   }