From 90be70ed0a4431a6b4d291e945df8f7643802ced Mon Sep 17 00:00:00 2001
From: hrmny <github.leah@hrmny.sh>
Date: Thu, 12 Oct 2023 20:22:24 +0200
Subject: [PATCH] fix(turbopack): always alias `server-only` and `client-only`

---
 .../crates/next-core/src/next_import_map.rs   | 56 ++++++++++++++++---
 1 file changed, 48 insertions(+), 8 deletions(-)

diff --git a/packages/next-swc/crates/next-core/src/next_import_map.rs b/packages/next-swc/crates/next-core/src/next_import_map.rs
index 631270403889b..13e360f084719 100644
--- a/packages/next-swc/crates/next-core/src/next_import_map.rs
+++ b/packages/next-swc/crates/next-core/src/next_import_map.rs
@@ -1,6 +1,7 @@
 use std::collections::{BTreeMap, HashMap};
 
 use anyhow::{Context, Result};
+use indexmap::{indexmap, IndexMap};
 use turbo_tasks::{Value, Vc};
 use turbopack_binding::{
     turbo::tasks_fs::{glob::Glob, FileSystem, FileSystemPath},
@@ -94,14 +95,7 @@ pub async fn get_next_client_import_map(
             } else {
                 ""
             };
-            import_map.insert_exact_alias(
-                "server-only",
-                request_to_import_mapping(app_dir, "next/dist/compiled/server-only"),
-            );
-            import_map.insert_exact_alias(
-                "client-only",
-                request_to_import_mapping(app_dir, "next/dist/compiled/client-only"),
-            );
+
             import_map.insert_exact_alias(
                 "react",
                 request_to_import_mapping(
@@ -154,6 +148,18 @@ pub async fn get_next_client_import_map(
         ClientContextType::Other => {}
     }
 
+    // see https://github.com/vercel/next.js/blob/8013ef7372fc545d49dbd060461224ceb563b454/packages/next/src/build/webpack-config.ts#L1449-L1531
+    insert_exact_alias_map(
+        &mut import_map,
+        project_path,
+        indexmap! {
+            "server-only" => "next/dist/compiled/server-only/index".to_string(),
+            "client-only" => "next/dist/compiled/client-only/index".to_string(),
+            "next/dist/compiled/server-only" => "next/dist/compiled/server-only/index".to_string(),
+            "next/dist/compiled/client-only" => "next/dist/compiled/client-only/index".to_string(),
+        },
+    );
+
     match ty.into_value() {
         ClientContextType::Pages { .. }
         | ClientContextType::App { .. }
@@ -829,6 +835,30 @@ async fn insert_next_server_special_aliases(
         (_, ServerContextType::Middleware) => {}
     }
 
+    // see https://github.com/vercel/next.js/blob/8013ef7372fc545d49dbd060461224ceb563b454/packages/next/src/build/webpack-config.ts#L1449-L1531
+    insert_exact_alias_map(
+        import_map,
+        project_path,
+        indexmap! {
+            "server-only" => "next/dist/compiled/server-only/empty".to_string(),
+            "client-only" => "next/dist/compiled/client-only/error".to_string(),
+            "next/dist/compiled/server-only" => "next/dist/compiled/server-only/empty".to_string(),
+            "next/dist/compiled/client-only" => "next/dist/compiled/client-only/error".to_string(),
+        },
+    );
+
+    if ty == ServerContextType::Middleware {
+        insert_exact_alias_map(
+            import_map,
+            project_path,
+            indexmap! {
+                "client-only" => "next/dist/compiled/client-only/index".to_string(),
+                "next/dist/compiled/client-only" => "next/dist/compiled/client-only/index".to_string(),
+                "next/dist/compiled/client-only/error" => "next/dist/compiled/client-only/index".to_string(),
+            },
+        );
+    }
+
     import_map.insert_exact_alias(
         "@vercel/og",
         external_if_node(
@@ -1022,6 +1052,16 @@ fn export_value_to_import_mapping(
     }
 }
 
+fn insert_exact_alias_map(
+    import_map: &mut ImportMap,
+    project_path: Vc<FileSystemPath>,
+    map: IndexMap<&'static str, String>,
+) {
+    for (pattern, request) in map {
+        import_map.insert_exact_alias(pattern, request_to_import_mapping(project_path, &request));
+    }
+}
+
 /// Inserts an alias to an alternative of import mappings into an import map.
 fn insert_alias_to_alternatives<'a>(
     import_map: &mut ImportMap,