feat(rslib): handle hashbang / react directives natively

crates/rspack_binding_api/src/fs_node/node.rs

@@ -11,6 +11,7 @@ type Write = ThreadsafeFunction<FnArgs<(i32, Buffer, u32)>, Promise<Either<u32,
 type Read = ThreadsafeFunction<FnArgs<(i32, u32, u32)>, Promise<Either<Buffer, ()>>>;
 type ReadUtil = ThreadsafeFunction<FnArgs<(i32, u8, u32)>, Promise<Either<Buffer, ()>>>;
 type ReadToEnd = ThreadsafeFunction<FnArgs<(i32, u32)>, Promise<Either<Buffer, ()>>>;
+type Chmod = ThreadsafeFunction<FnArgs<(String, u32)>, Promise<()>>;
 
 #[derive(Debug)]
 #[napi(object, object_to_js = false, js_name = "ThreadsafeNodeFS")]
@@ -53,7 +54,7 @@ pub struct ThreadsafeNodeFS {
   pub read_to_end: ReadToEnd,
   // The following functions are not supported by webpack, so they are optional
   #[napi(ts_type = "(name: string, mode: number) => Promise<void>")]
-  pub chmod: Option<ThreadsafeFunction<(String, u32), Promise<()>>>,
+  pub chmod: Option<Chmod>,
 }
 
 #[napi(object, object_to_js = false)]

crates/rspack_binding_api/src/fs_node/write.rs

@@ -134,7 +134,10 @@ impl WritableFileSystem for NodeFileSystem {
       && let Some(chmod) = &self.0.chmod
     {
       let file = path.as_str().to_string();
-      return chmod.call_with_promise((file, mode)).await.to_fs_result();
+      return chmod
+        .call_with_promise((file, mode).into())
+        .await
+        .to_fs_result();
     }
     Ok(())
   }

crates/rspack_core/src/utils/mod.rs

@@ -4,7 +4,8 @@ use rspack_collections::Identifier;
 use rspack_util::comparators::{compare_ids, compare_numbers};
 
 use crate::{
-  BoxModule, ChunkGraph, ChunkGroupByUkey, ChunkGroupUkey, ChunkUkey, Compilation, ModuleGraph,
+  BoxModule, ChunkGraph, ChunkGroupByUkey, ChunkGroupUkey, ChunkUkey, Compilation,
+  ConcatenatedModule, ModuleGraph, ModuleIdentifier,
 };
 mod comment;
 mod compile_boolean_matcher;
@@ -145,6 +146,65 @@ pub fn compare_modules_by_identifier(a: &BoxModule, b: &BoxModule) -> std::cmp::
   compare_ids(&a.identifier(), &b.identifier())
 }
 
+/// # Returns
+/// - `Some(String)` if a hashbang is found in the module's build_info extras
+/// - `None` if no hashbang is present or the module doesn't exist
+pub fn get_module_hashbang(
+  module_graph: &ModuleGraph,
+  module_id: &ModuleIdentifier,
+) -> Option<String> {
+  let module = module_graph.module_by_identifier(module_id)?;
+
+  let build_info =
+    if let Some(concatenated_module) = module.as_any().downcast_ref::<ConcatenatedModule>() {
+      // For concatenated modules, get the root module's build_info
+      let root_module_id = concatenated_module.get_root();
+      module_graph
+        .module_by_identifier(&root_module_id)
+        .map_or_else(|| module.build_info(), |m| m.build_info())
+    } else {
+      module.build_info()
+    };
+
+  build_info
+    .extras
+    .get("hashbang")
+    .and_then(|v| v.as_str())
+    .map(|s| s.to_string())
+}
+
+/// # Returns
+/// - `Some(Vec<String>)` if directives are found in the module's build_info extras
+/// - `None` if no directives are present or the module doesn't exist
+pub fn get_module_directives(
+  module_graph: &ModuleGraph,
+  module_id: &ModuleIdentifier,
+) -> Option<Vec<String>> {
+  let module = module_graph.module_by_identifier(module_id)?;
+
+  let build_info =
+    if let Some(concatenated_module) = module.as_any().downcast_ref::<ConcatenatedModule>() {
+      // For concatenated modules, get the root module's build_info
+      let root_module_id = concatenated_module.get_root();
+      module_graph
+        .module_by_identifier(&root_module_id)
+        .map_or_else(|| module.build_info(), |m| m.build_info())
+    } else {
+      module.build_info()
+    };
+
+  build_info
+    .extras
+    .get("react_directives")
+    .and_then(|v| v.as_array())
+    .map(|arr| {
+      arr
+        .iter()
+        .filter_map(|v| v.as_str().map(|s| s.to_string()))
+        .collect()
+    })
+}
+
 pub fn compare_module_iterables(modules_a: &[&BoxModule], modules_b: &[&BoxModule]) -> Ordering {
   let mut a_iter = modules_a.iter();
   let mut b_iter = modules_b.iter();

crates/rspack_plugin_esm_library/src/render.rs

@@ -5,8 +5,8 @@ use rspack_collections::{IdentifierIndexSet, UkeyIndexMap, UkeySet};
 use rspack_core::{
   AssetInfo, Chunk, ChunkGraph, ChunkRenderContext, ChunkUkey, CodeGenerationDataFilename,
   Compilation, ConcatenatedModuleInfo, DependencyId, InitFragment, ModuleIdentifier, PathData,
-  PathInfo, RuntimeGlobals, SourceType, get_js_chunk_filename_template, get_undo_path,
-  render_init_fragments,
+  PathInfo, RuntimeGlobals, SourceType, get_js_chunk_filename_template, get_module_directives,
+  get_module_hashbang, get_undo_path, render_init_fragments,
   rspack_sources::{ConcatSource, RawStringSource, ReplaceSource, Source, SourceExt},
 };
 use rspack_error::Result;
@@ -85,6 +85,49 @@ impl EsmLibraryPlugin {
 
     let mut chunk_init_fragments: Vec<Box<dyn InitFragment<ChunkRenderContext> + 'static>> =
       chunk_link.init_fragments.clone();
+
+    // NOTE: Similar hashbang and directives handling logic.
+    // See rspack_plugin_rslib/src/plugin.rs render() for why this duplication is necessary.
+    let entry_modules = compilation.chunk_graph.get_chunk_entry_modules(chunk_ukey);
+    for entry_module_id in &entry_modules {
+      let hashbang = get_module_hashbang(&module_graph, entry_module_id);
+      let directives = get_module_directives(&module_graph, entry_module_id);
+
+      if hashbang.is_none() && directives.is_none() {
+        continue;
+      }
+
+      if let Some(hashbang) = &hashbang {
+        chunk_init_fragments.insert(
+          0,
+          Box::new(rspack_core::NormalInitFragment::new(
+            format!("{hashbang}\n"),
+            rspack_core::InitFragmentStage::StageConstants,
+            i32::MIN,
+            rspack_core::InitFragmentKey::unique(),
+            None,
+          )),
+        );
+      }
+
+      if let Some(directives) = directives {
+        for (idx, directive) in directives.iter().enumerate() {
+          let insert_pos = if hashbang.is_some() { 1 + idx } else { idx };
+          chunk_init_fragments.insert(
+            insert_pos,
+            Box::new(rspack_core::NormalInitFragment::new(
+              format!("{directive}\n"),
+              rspack_core::InitFragmentStage::StageConstants,
+              i32::MIN + 1 + idx as i32,
+              rspack_core::InitFragmentKey::unique(),
+              None,
+            )),
+          );
+        }
+      }
+      break; // Only process the first entry module with hashbang/directives
+    }
+
     let mut replace_auto_public_path = false;
     let mut replace_static_url = false;
 

crates/rspack_plugin_rslib/Cargo.toml

@@ -11,6 +11,7 @@ version.workspace = true
 rspack_cacheable         = { workspace = true }
 rspack_core              = { workspace = true }
 rspack_error             = { workspace = true }
+rspack_fs                = { workspace = true }
 rspack_hash              = { workspace = true }
 rspack_hook              = { workspace = true }
 rspack_plugin_asset      = { workspace = true }

crates/rspack_plugin_rslib/src/hashbang_parser_plugin.rs

@@ -0,0 +1,44 @@
+use rspack_core::ConstDependency;
+use rspack_plugin_javascript::{JavascriptParserPlugin, visitors::JavascriptParser};
+use swc_core::ecma::ast::Program;
+
+pub struct HashbangParserPlugin;
+
+impl JavascriptParserPlugin for HashbangParserPlugin {
+  fn program(&self, parser: &mut JavascriptParser, ast: &Program) -> Option<bool> {
+    let hashbang = ast
+      .as_module()
+      .and_then(|m| m.shebang.as_ref())
+      .or_else(|| ast.as_script().and_then(|s| s.shebang.as_ref()))?;
+
+    // Normalize hashbang to always include "#!" prefix
+    // SWC may omit the leading "#!" in the shebang value
+    let normalized_hashbang = if hashbang.starts_with("#!") {
+      hashbang.to_string()
+    } else {
+      format!("#!{}", hashbang)
+    };
+
+    // Store hashbang in build_info for later use during rendering
+    parser.build_info.extras.insert(
+      "hashbang".to_string(),
+      serde_json::Value::String(normalized_hashbang),
+    );
+
+    // Remove hashbang from source code
+    // If SWC omitted "#!", we still need to remove those two characters
+    let replace_len = if hashbang.starts_with("#!") {
+      hashbang.len() as u32
+    } else {
+      hashbang.len() as u32 + 2 // include "#!"
+    };
+
+    parser.add_presentational_dependency(Box::new(ConstDependency::new(
+      (0, replace_len).into(),
+      "".into(),
+      None,
+    )));
+
+    None
+  }
+}

crates/rspack_plugin_rslib/src/lib.rs

@@ -1,6 +1,8 @@
 mod asset;
+mod hashbang_parser_plugin;
 mod import_dependency;
 mod import_external;
 mod parser_plugin;
 mod plugin;
+mod react_directives_parser_plugin;
 pub use plugin::*;

crates/rspack_plugin_rslib/src/plugin.rs

@@ -4,20 +4,24 @@ use std::{
 };
 
 use rspack_core::{
-  Compilation, CompilationParams, CompilerCompilation, CompilerFinishMake, ModuleType,
-  NormalModuleFactoryParser, ParserAndGenerator, ParserOptions, Plugin,
+  AssetEmittedInfo, ChunkUkey, Compilation, CompilationParams, CompilerAssetEmitted,
+  CompilerCompilation, CompilerFinishMake, ModuleType, NormalModuleFactoryParser,
+  ParserAndGenerator, ParserOptions, Plugin, get_module_directives, get_module_hashbang,
+  rspack_sources::{ConcatSource, RawStringSource, Source, SourceExt},
 };
 use rspack_error::Result;
 use rspack_hook::{plugin, plugin_hook};
 use rspack_plugin_asset::AssetParserAndGenerator;
 use rspack_plugin_javascript::{
-  BoxJavascriptParserPlugin, parser_and_generator::JavaScriptParserAndGenerator,
+  BoxJavascriptParserPlugin, JavascriptModulesRender, JsPlugin, RenderSource,
+  parser_and_generator::JavaScriptParserAndGenerator,
 };
 
 use crate::{
-  asset::RslibAssetParserAndGenerator, import_dependency::RslibDependencyTemplate,
+  asset::RslibAssetParserAndGenerator, hashbang_parser_plugin::HashbangParserPlugin,
+  import_dependency::RslibDependencyTemplate,
   import_external::replace_import_dependencies_for_external_modules,
-  parser_plugin::RslibParserPlugin,
+  parser_plugin::RslibParserPlugin, react_directives_parser_plugin::ReactDirectivesParserPlugin,
 };
 
 #[derive(Debug)]
@@ -54,6 +58,8 @@ async fn nmf_parser(
 ) -> Result<()> {
   if let Some(parser) = parser.downcast_mut::<JavaScriptParserAndGenerator>() {
     if module_type.is_js_like() {
+      parser.add_parser_plugin(Box::new(HashbangParserPlugin) as BoxJavascriptParserPlugin);
+      parser.add_parser_plugin(Box::new(ReactDirectivesParserPlugin) as BoxJavascriptParserPlugin);
       parser.add_parser_plugin(
         Box::new(RslibParserPlugin::new(self.options.intercept_api_plugin))
           as BoxJavascriptParserPlugin,
@@ -88,6 +94,71 @@ async fn compilation(
     RslibDependencyTemplate::template_type(),
     Arc::new(RslibDependencyTemplate::default()),
   );
+
+  // Register render hook for hashbang and directives handling during chunk generation
+  let hooks = JsPlugin::get_compilation_hooks_mut(compilation.id());
+  let mut hooks = hooks.write().await;
+  hooks.render.tap(render::new(self));
+  drop(hooks);
+
+  Ok(())
+}
+
+#[plugin_hook(JavascriptModulesRender for RslibPlugin)]
+async fn render(
+  &self,
+  compilation: &Compilation,
+  chunk_ukey: &ChunkUkey,
+  render_source: &mut RenderSource,
+) -> Result<()> {
+  // NOTE: This function handles hashbang and directives for non new ESM library formats.
+  // Similar logic exists in rspack_plugin_esm_library/src/render.rs for ESM format,
+  // as that plugin's render path is used instead when ESM library plugin is enabled.
+  let entry_modules = compilation.chunk_graph.get_chunk_entry_modules(chunk_ukey);
+  if entry_modules.is_empty() {
+    return Ok(());
+  }
+
+  let module_graph = compilation.get_module_graph();
+
+  for entry_module_id in &entry_modules {
+    let hashbang = get_module_hashbang(&module_graph, entry_module_id);
+    let directives = get_module_directives(&module_graph, entry_module_id);
+
+    if hashbang.is_none() && directives.is_none() {
+      continue;
+    }
+
+    let original_source_str = render_source.source.source().into_string_lossy();
+
+    let mut new_source = ConcatSource::default();
+
+    if let Some(hashbang) = hashbang {
+      new_source.add(RawStringSource::from(format!("{}\n", hashbang)));
+    }
+
+    if let Some(directives) = directives {
+      let use_strict_prefix = "\"use strict\";\n";
+      if let Some(rest) = original_source_str.strip_prefix(use_strict_prefix) {
+        new_source.add(RawStringSource::from(use_strict_prefix));
+        for directive in directives {
+          new_source.add(RawStringSource::from(format!("{}\n", directive)));
+        }
+        new_source.add(RawStringSource::from(rest));
+      } else {
+        for directive in directives {
+          new_source.add(RawStringSource::from(format!("{}\n", directive)));
+        }
+        new_source.add(render_source.source.clone());
+      }
+    } else {
+      new_source.add(render_source.source.clone());
+    }
+
+    render_source.source = new_source.boxed();
+    break;
+  }
+
   Ok(())
 }
 
@@ -98,6 +169,26 @@ async fn finish_make(&self, compilation: &mut Compilation) -> Result<()> {
   Ok(())
 }
 
+#[plugin_hook(CompilerAssetEmitted for RslibPlugin)]
+async fn asset_emitted(
+  &self,
+  compilation: &Compilation,
+  _filename: &str,
+  info: &AssetEmittedInfo,
+) -> Result<()> {
+  use rspack_fs::FilePermissions;
+
+  let content = info.source.source().into_string_lossy();
+  if content.starts_with("#!") {
+    let output_fs = &compilation.output_filesystem;
+    let permissions = FilePermissions::from_mode(0o755);
+    output_fs
+      .set_permissions(&info.target_path, permissions)
+      .await?;
+  }
+  Ok(())
+}
+
 impl Plugin for RslibPlugin {
   fn name(&self) -> &'static str {
     "rslib"
@@ -111,6 +202,10 @@ impl Plugin for RslibPlugin {
       .tap(nmf_parser::new(self));
 
     ctx.compiler_hooks.finish_make.tap(finish_make::new(self));
+    ctx
+      .compiler_hooks
+      .asset_emitted
+      .tap(asset_emitted::new(self));
 
     Ok(())
   }