Turbopack: Strip relative path prefix when generating PageLoaderAsset (…

…#54040)

### What?

Strip the relative path prefix (`_next/`) when generating the `PageLoaderAsset`. This is necessary because the page loader will internally use `__turbopack_load__`, which prepends the prefix back onto the path.

### Why?

Without this, we'd try loading `_next/_next/path/to/file.js`, because we'd prepend the prefix onto a path that already contains it.

### How?

When generating the page loader asset, we "proxy" the `OutputAsset` onto a path which has the prefix removed.

~~Depends on vercel/turbo#5717

Closes WEB-1377

Cargo.toml

@@ -46,11 +46,11 @@ swc_core = { version = "0.79.59" }
 testing = { version = "0.33.21" }
 
 # Turbo crates
-turbopack-binding = { git = "https://github.com/vercel/turbo.git", tag = "turbopack-230814.2" }
+turbopack-binding = { git = "https://github.com/vercel/turbo.git", tag = "turbopack-230816.1" }
 # [TODO]: need to refactor embed_directory! macro usages, as well as resolving turbo_tasks::function, macros..
-turbo-tasks = { git = "https://github.com/vercel/turbo.git", tag = "turbopack-230814.2" }
+turbo-tasks = { git = "https://github.com/vercel/turbo.git", tag = "turbopack-230816.1" }
 # [TODO]: need to refactor embed_directory! macro usage in next-core
-turbo-tasks-fs = { git = "https://github.com/vercel/turbo.git", tag = "turbopack-230814.2" }
+turbo-tasks-fs = { git = "https://github.com/vercel/turbo.git", tag = "turbopack-230816.1" }
 
 # General Deps
 
@@ -123,7 +123,9 @@ serde = { version = "1.0.152", features = ["derive"] }
 serde_json = "1.0.93"
 serde_qs = "0.11.0"
 serde_yaml = "0.9.17"
-shadow-rs = { version = "0.23.0", default-features = false, features = ["tzdb"] }
+shadow-rs = { version = "0.23.0", default-features = false, features = [
+  "tzdb",
+] }
 syn = "1.0.107"
 tempfile = "3.3.0"
 thiserror = "1.0.38"

packages/next-swc/crates/next-api/src/pages.rs

@@ -24,7 +24,7 @@ use next_core::{
 use serde::{Deserialize, Serialize};
 use turbo_tasks::{trace::TraceRawVcs, Completion, TaskInput, TryJoinIterExt, Value, Vc};
 use turbopack_binding::{
-    turbo::tasks_fs::{File, FileSystem, FileSystemPath, VirtualFileSystem},
+    turbo::tasks_fs::{File, FileSystem, FileSystemPath, FileSystemPathOption, VirtualFileSystem},
     turbopack::{
         build::BuildChunkingContext,
         core::{
@@ -567,6 +567,7 @@ impl PageEndpoint {
             Vc::upcast(client_chunking_context),
             self.source(),
             this.pathname,
+            self.client_relative_path(),
         )));
 
         Ok(Vc::cell(client_chunks))
@@ -811,6 +812,11 @@ impl PageEndpoint {
 
         Ok(page_output.cell())
     }
+
+    #[turbo_tasks::function]
+    fn client_relative_path(&self) -> Vc<FileSystemPathOption> {
+        Vc::cell(Some(self.pages_project.project().client_relative_path()))
+    }
 }
 
 #[turbo_tasks::value_impl]

packages/next-swc/crates/next-core/js/package.json

@@ -10,8 +10,8 @@
     "check": "tsc --noEmit"
   },
   "dependencies": {
-    "@vercel/turbopack-ecmascript-runtime": "https://gitpkg-fork.vercel.sh/vercel/turbo/crates/turbopack-ecmascript-runtime/js?turbopack-230814.2",
-    "@vercel/turbopack-node": "https://gitpkg-fork.vercel.sh/vercel/turbo/crates/turbopack-node/js?turbopack-230814.2",
+    "@vercel/turbopack-ecmascript-runtime": "https://gitpkg-fork.vercel.sh/vercel/turbo/crates/turbopack-ecmascript-runtime/js?turbopack-230816.1",
+    "@vercel/turbopack-node": "https://gitpkg-fork.vercel.sh/vercel/turbo/crates/turbopack-node/js?turbopack-230816.1",
     "anser": "^2.1.1",
     "css.escape": "^1.5.1",
     "next": "*",