add ServerDirective transform which reports unsupported (vercel/turborepo#4477)

### Description

"use server" isn't supported yet, but we want to have an error message

Author: sokra

crates/turbopack-ecmascript/src/parse.rs

@@ -23,7 +23,7 @@ use turbo_tasks::{
     primitives::{StringVc, U64Vc},
     Value, ValueToString,
 };
-use turbo_tasks_fs::{FileContent, FileSystemPath};
+use turbo_tasks_fs::{FileContent, FileSystemPath, FileSystemPathVc};
 use turbo_tasks_hash::hash_xxh3_hash64;
 use turbopack_core::{
     asset::{Asset, AssetContent, AssetVc},
@@ -142,7 +142,8 @@ pub async fn parse(
     transforms: EcmascriptInputTransformsVc,
 ) -> Result<ParseResultVc> {
     let content = source.content();
-    let fs_path = &*source.ident().path().await?;
+    let fs_path_vc = source.ident().path();
+    let fs_path = &*fs_path_vc.await?;
     let ident = &*source.ident().to_string().await?;
     let file_path_hash = *hash_ident(source.ident().to_string()).await? as u128;
     let ty = ty.into_value();
@@ -154,6 +155,7 @@ pub async fn parse(
                     let transforms = &*transforms.await?;
                     match parse_content(
                         string.into_owned(),
+                        fs_path_vc,
                         fs_path,
                         ident,
                         file_path_hash,
@@ -182,6 +184,7 @@ pub async fn parse(
 
 async fn parse_content(
     string: String,
+    fs_path_vc: FileSystemPathVc,
     fs_path: &FileSystemPath,
     ident: &str,
     file_path_hash: u128,
@@ -297,6 +300,7 @@ async fn parse_content(
                 file_path_str: &fs_path.path,
                 file_name_str: fs_path.file_name(),
                 file_name_hash: file_path_hash,
+                file_path: fs_path_vc,
             };
             for transform in transforms.iter() {
                 transform.apply(&mut parsed_program, &context).await?;

crates/turbopack-ecmascript/src/transform/mod.rs

@@ -1,4 +1,5 @@
 mod server_to_client_proxy;
+mod util;
 
 use std::{fmt::Debug, path::Path, sync::Arc};
 
@@ -15,17 +16,25 @@ use swc_core::{
         },
         visit::{FoldWith, VisitMutWith},
     },
+    quote,
 };
 use turbo_tasks::primitives::{OptionStringVc, StringVc};
-use turbo_tasks_fs::json::parse_json_with_source_context;
-use turbopack_core::environment::EnvironmentVc;
+use turbo_tasks_fs::{json::parse_json_with_source_context, FileSystemPathVc};
+use turbopack_core::{
+    environment::EnvironmentVc,
+    issue::{Issue, IssueSeverity, IssueSeverityVc, IssueVc},
+};
 
-use self::server_to_client_proxy::{create_proxy_module, is_client_module};
+use self::{
+    server_to_client_proxy::create_proxy_module,
+    util::{is_client_module, is_server_module},
+};
 
 #[turbo_tasks::value(serialization = "auto_for_input")]
 #[derive(Debug, Clone, PartialOrd, Ord, Hash)]
 pub enum EcmascriptInputTransform {
     ClientDirective(StringVc),
+    ServerDirective(StringVc),
     CommonJs,
     Custom(CustomTransformVc),
     Emotion,
@@ -104,6 +113,7 @@ pub struct TransformContext<'a> {
     pub file_path_str: &'a str,
     pub file_name_str: &'a str,
     pub file_name_hash: u128,
+    pub file_path: FileSystemPathVc,
 }
 
 impl EcmascriptInputTransform {
@@ -115,6 +125,7 @@ impl EcmascriptInputTransform {
             unresolved_mark,
             file_name_str,
             file_name_hash,
+            file_path,
             ..
         } = ctx;
         match self {
@@ -250,12 +261,28 @@ impl EcmascriptInputTransform {
                 ));
             }
             EcmascriptInputTransform::ClientDirective(transition_name) => {
-                let transition_name = &*transition_name.await?;
                 if is_client_module(program) {
+                    let transition_name = &*transition_name.await?;
                     *program = create_proxy_module(transition_name, &format!("./{file_name_str}"));
                     program.visit_mut_with(&mut resolver(unresolved_mark, top_level_mark, false));
                 }
             }
+            EcmascriptInputTransform::ServerDirective(_transition_name) => {
+                if is_server_module(program) {
+                    let stmt = quote!(
+                        "throw new Error('Server actions (\"use server\") are not yet supported in \
+                         Turbopack');" as Stmt
+                    );
+                    match program {
+                        Program::Module(m) => m.body = vec![ModuleItem::Stmt(stmt)],
+                        Program::Script(s) => s.body = vec![stmt],
+                    }
+                    UnsupportedServerActionIssue { context: file_path }
+                        .cell()
+                        .as_issue()
+                        .emit();
+                }
+            }
             EcmascriptInputTransform::Custom(transform) => {
                 if let Some(output) = transform.await?.transform(program, ctx) {
                     *program = output;
@@ -291,3 +318,36 @@ fn unwrap_module_program(program: &mut Program) -> Program {
         }),
     }
 }
+
+#[turbo_tasks::value(shared)]
+pub struct UnsupportedServerActionIssue {
+    pub context: FileSystemPathVc,
+}
+
+#[turbo_tasks::value_impl]
+impl Issue for UnsupportedServerActionIssue {
+    #[turbo_tasks::function]
+    fn severity(&self) -> IssueSeverityVc {
+        IssueSeverity::Error.into()
+    }
+
+    #[turbo_tasks::function]
+    fn category(&self) -> StringVc {
+        StringVc::cell("unsupported".to_string())
+    }
+
+    #[turbo_tasks::function]
+    fn title(&self) -> StringVc {
+        StringVc::cell("Server actions (\"use server\") are not yet supported in Turbopack".into())
+    }
+
+    #[turbo_tasks::function]
+    fn context(&self) -> FileSystemPathVc {
+        self.context
+    }
+
+    #[turbo_tasks::function]
+    async fn description(&self) -> Result<StringVc> {
+        Ok(StringVc::cell("".to_string()))
+    }
+}

crates/turbopack-ecmascript/src/transform/server_to_client_proxy.rs

@@ -13,29 +13,6 @@ use swc_core::{
 
 use crate::references::TURBOPACK_HELPER;
 
-macro_rules! has_client_directive {
-    ($stmts:expr) => {
-        $stmts
-            .map(|item| {
-                if let Lit::Str(str) = item?.as_expr()?.expr.as_lit()? {
-                    Some(str)
-                } else {
-                    None
-                }
-            })
-            .take_while(Option::is_some)
-            .map(Option::unwrap)
-            .any(|s| &*s.value == "use client")
-    };
-}
-
-pub fn is_client_module(program: &Program) -> bool {
-    match program {
-        Program::Module(m) => has_client_directive!(m.body.iter().map(|item| item.as_stmt())),
-        Program::Script(s) => has_client_directive!(s.body.iter().map(Some)),
-    }
-}
-
 pub fn create_proxy_module(transition_name: &str, target_import: &str) -> Program {
     let ident = private_ident!("createProxy");
     Program::Module(Module {

crates/turbopack-ecmascript/src/transform/util.rs

@@ -0,0 +1,35 @@
+use swc_core::ecma::ast::{Lit, Program};
+
+macro_rules! has_directive {
+    ($stmts:expr, $name:literal) => {
+        $stmts
+            .map(|item| {
+                if let Lit::Str(str) = item?.as_expr()?.expr.as_lit()? {
+                    Some(str)
+                } else {
+                    None
+                }
+            })
+            .take_while(Option::is_some)
+            .map(Option::unwrap)
+            .any(|s| &*s.value == $name)
+    };
+}
+
+pub fn is_client_module(program: &Program) -> bool {
+    match program {
+        Program::Module(m) => {
+            has_directive!(m.body.iter().map(|item| item.as_stmt()), "use client")
+        }
+        Program::Script(s) => has_directive!(s.body.iter().map(Some), "use client"),
+    }
+}
+
+pub fn is_server_module(program: &Program) -> bool {
+    match program {
+        Program::Module(m) => {
+            has_directive!(m.body.iter().map(|item| item.as_stmt()), "use server")
+        }
+        Program::Script(s) => has_directive!(s.body.iter().map(Some), "use server"),
+    }
+}