feat: prepend comment node

packages/react-server-component/src/lib.rs

@@ -1,6 +1,7 @@
 use serde::Deserialize;
 use swc_core::{
   common::{
+    comments::{Comment, CommentKind, Comments},
     FileName,
     Span,DUMMY_SP,
     errors::HANDLER
@@ -11,16 +12,19 @@ use swc_core::{
       visit::{Fold, FoldWith, VisitMut, as_folder, noop_visit_mut_type, VisitMutWith},
       utils::{prepend_stmts, quote_ident, quote_str, ExprFactory}
   },
-  plugin::{plugin_transform, proxies::TransformPluginProgramMetadata, metadata::TransformPluginMetadataContextKind},
+  plugin::{plugin_transform, proxies::{TransformPluginProgramMetadata, PluginCommentsProxy}, metadata::TransformPluginMetadataContextKind},
 };
 
 struct ModuleImports {
   source: (JsWord, Span),
   specifiers: Vec<(JsWord, Span)>,
 }
 
-pub fn react_server_component(file_name: FileName, is_server: bool) -> impl Fold + VisitMut {
+pub fn react_server_component<C>(file_name: FileName, is_server: bool, comments: C) -> impl Fold + VisitMut
+where C: Comments,
+{
   as_folder(ReactServerComponent {
+    comments,
     filepath: file_name.to_string(),
     is_server,
     export_names: vec![],
@@ -59,17 +63,17 @@ struct Config {
   pub is_server: bool
 }
 
-struct ReactServerComponent {
+struct ReactServerComponent<C: Comments> {
   filepath: String,
   is_server: bool,
+  comments: C,
   export_names: Vec<String>,
   invalid_server_imports: Vec<JsWord>,
   invalid_client_imports: Vec<JsWord>,
   invalid_server_react_apis: Vec<JsWord>,
   invalid_server_ice_imports: Vec<JsWord>,
 }
-
-impl ReactServerComponent {
+impl<C: Comments> ReactServerComponent<C>  {
   fn create_module_proxy(&self, module: &mut Module) {
     // Clear all statements and module decalarations.
     module.body.clear();
@@ -127,6 +131,7 @@ impl ReactServerComponent {
         })),
       ].into_iter(),
     );
+    self.prepend_comment_node(module);
   }
 
   fn collect_top_level_directives_and_imports(&mut self, module: &mut Module) -> (bool, bool, Vec<ModuleImports>) {
@@ -348,13 +353,27 @@ impl ReactServerComponent {
       }
     }
   }
+
+  fn prepend_comment_node(&self, module: &Module) {
+    // Prepend a special comment at the top of file, so that we can identify client boundary in webpack plugin
+    // just by reading the firist line of file.
+    self.comments.add_leading(
+      module.span.lo,
+      Comment {
+        kind: CommentKind::Block,
+        span: DUMMY_SP,
+        text: format!("__ice_internal_client_entry_do_not_use__ {}", self.export_names.join(",")).into(),
+      },
+    );
+  }
 }
 
-impl VisitMut for ReactServerComponent {
+impl <C: Comments> VisitMut for ReactServerComponent<C> {
   noop_visit_mut_type!();
 
   fn visit_mut_module(&mut self, module: &mut Module) {
     let (is_client_entry, is_action_file, imports) = self.collect_top_level_directives_and_imports(module);
+    tracing::debug!("is_client_entry: {}, is_action_file: {}", is_client_entry, is_action_file);
     if self.is_server {
       if !is_client_entry {
         self.assert_server_import(&imports);
@@ -367,7 +386,9 @@ impl VisitMut for ReactServerComponent {
       if !is_action_file {
         self.assert_client_import(&imports);
       }
-      // TODO: handle client entry in the future.
+      if is_client_entry {
+        self.prepend_comment_node(module);
+      }
     }
     module.visit_mut_children_with(self)
   }
@@ -385,5 +406,5 @@ pub fn process_transform(program: Program, _metadata: TransformPluginProgramMeta
     Some(s) => FileName::Real(s.into()),
     None => FileName::Anon,
   };
-  program.fold_with(&mut react_server_component(file_name, config.is_server))
+  program.fold_with(&mut react_server_component(file_name, config.is_server, PluginCommentsProxy))
 }

packages/react-server-component/tests/fixture.rs

@@ -7,14 +7,14 @@ use swc_core::{
 use swc_plugin_react_server_component::react_server_component;
 
 #[fixture("tests/fixture/server/**/input.js")]
-fn fixture(input: PathBuf) {
+fn fixture_server(input: PathBuf) {
   let parent = input.parent().unwrap();
   let output = parent.join("output.js");
 
   test_fixture(
     Default::default(),
-    &|_t| {
-      react_server_component(FileName::Real("file_path.js".into()), true)
+    &|t| {
+      react_server_component(FileName::Real("file_path.js".into()), true, t.comments.clone())
     },
     &input,
     &output,
@@ -23,3 +23,21 @@ fn fixture(input: PathBuf) {
     },
   );
 }
+
+#[fixture("tests/fixture/client/**/input.js")]
+fn fixture_client(input: PathBuf) {
+  let parent = input.parent().unwrap();
+  let output = parent.join("output.js");
+
+  test_fixture(
+    Default::default(),
+    &|t| {
+      react_server_component(FileName::Real("file_path.js".into()), false, t.comments.clone())
+    },
+    &input,
+    &output,
+    FixtureTestConfig {
+      ..Default::default()
+    },
+  );
+}

packages/react-server-component/tests/fixture/client/sever-component/input.js

@@ -0,0 +1,3 @@
+export default function Home() {
+  return 'home';
+}

packages/react-server-component/tests/fixture/client/sever-component/output.js

@@ -0,0 +1,3 @@
+export default function Home() {
+  return 'home';
+}

packages/react-server-component/tests/fixture/client/use-client/input.js

@@ -0,0 +1,9 @@
+'use client';
+
+import react from "react";
+
+export default function Home() {
+  return 'home';
+}
+
+export const dataLoader = {};

packages/react-server-component/tests/fixture/client/use-client/output.js

@@ -0,0 +1,7 @@
+/*__ice_internal_client_entry_do_not_use__ default,dataLoader*/ import react from "react";
+
+export default function Home() {
+  return 'home';
+}
+
+export const dataLoader = {};

packages/react-server-component/tests/fixture/server/server-component/input.js

@@ -1,3 +1,4 @@
+// comments
 export default function () {
   return null
 }

packages/react-server-component/tests/fixture/server/server-component/output.js

@@ -1,3 +1,4 @@
+// comments
 export default function () {
   return null
 }

packages/react-server-component/tests/fixture/server/use-client/output.js

@@ -1,2 +1,2 @@
-const { createClientModuleProxy } = require("react-server-dom-webpack/server.node");
+/*__ice_internal_client_entry_do_not_use__ default*/ const { createClientModuleProxy } = require("react-server-dom-webpack/server.node");
 module.exports = createClientModuleProxy("file_path.js");