fix: hoisted import declaration (#80)

crates/rolldown/src/bundler/visitors/commonjs_source_render.rs

@@ -36,4 +36,9 @@ impl<'ast> Visit<'ast> for CommonJsSourceRender<'ast> {
   fn visit_import_declaration(&mut self, decl: &'ast oxc::ast::ast::ImportDeclaration<'ast>) {
     self.ctx.visit_import_declaration(decl);
   }
+
+  fn visit_statement(&mut self, stmt: &'ast oxc::ast::ast::Statement<'ast>) {
+    self.ctx.visit_statement(stmt);
+    self.visit_statement_match(stmt);
+  }
 }

crates/rolldown/src/bundler/visitors/esm_source_render.rs

@@ -97,4 +97,9 @@ impl<'ast> Visit<'ast> for EsmSourceRender<'ast> {
     }
     self.visit_expression(&expr.callee);
   }
+
+  fn visit_statement(&mut self, stmt: &'ast oxc::ast::ast::Statement<'ast>) {
+    self.ctx.visit_statement(stmt);
+    self.visit_statement_match(stmt);
+  }
 }

crates/rolldown/src/bundler/visitors/esm_wrap_source_render.rs

@@ -164,4 +164,9 @@ impl<'ast> Visit<'ast> for EsmWrapSourceRender<'ast> {
     }
     self.visit_expression(&expr.callee);
   }
+
+  fn visit_statement(&mut self, stmt: &'ast oxc::ast::ast::Statement<'ast>) {
+    self.ctx.visit_statement(stmt);
+    self.visit_statement_match(stmt);
+  }
 }

crates/rolldown/src/bundler/visitors/mod.rs

@@ -5,7 +5,7 @@ pub mod scanner;
 use index_vec::IndexVec;
 use oxc::{
   semantic::ReferenceId,
-  span::{Atom, Span},
+  span::{Atom, GetSpan, Span},
 };
 use rolldown_common::{ExportsKind, ModuleId, SymbolRef};
 use rustc_hash::FxHashMap;
@@ -30,6 +30,8 @@ pub struct RendererContext<'ast> {
   namespace_symbol_name: Option<&'ast Atom>,
   default_symbol_name: Option<&'ast Atom>,
   runtime: &'ast Runtime,
+  // Used to hoisted import declaration before the first statement
+  first_stmt_start: Option<u32>,
 }
 
 impl<'ast> RendererContext<'ast> {
@@ -66,6 +68,7 @@ impl<'ast> RendererContext<'ast> {
       namespace_symbol_name,
       default_symbol_name,
       runtime,
+      first_stmt_start: None,
     }
   }
 
@@ -153,6 +156,7 @@ impl<'ast> RendererContext<'ast> {
     self.remove_node(decl.span);
     let rec = &self.module.import_records[self.module.imports.get(&decl.span).copied().unwrap()];
     let importee = &self.modules[rec.resolved_module];
+    let start = self.first_stmt_start.unwrap_or(decl.span.start);
     if let Module::Normal(importee) = importee {
       if importee.exports_kind == ExportsKind::CommonJs {
         // add import cjs symbol binding
@@ -161,8 +165,8 @@ impl<'ast> RendererContext<'ast> {
           .unwrap();
         let wrap_symbol_name = self.get_symbol_final_name(importee.wrap_symbol.unwrap()).unwrap();
         let to_esm_runtime_symbol_name = self.get_runtime_symbol_final_name(&"__toESM".into());
-        self.source.prepend_left(
-          decl.span.start,
+        self.source.append_right(
+          start,
           format!(
             "var {namespace_name} = {to_esm_runtime_symbol_name}({wrap_symbol_name}(){});\n",
             if self.module.module_type.is_esm() { ", 1" } else { "" }
@@ -173,27 +177,22 @@ impl<'ast> RendererContext<'ast> {
             if let Some(name) = self.get_symbol_final_name(
               (importee.id, importee.cjs_symbols[spec.imported.name()].symbol).into(),
             ) {
-              self
-                .source
-                .prepend_right(decl.span.start, format!("var {name} = {namespace_name}.{name};\n"));
+              self.source.append_right(start, format!("var {name} = {namespace_name}.{name};\n"));
             }
           }
           oxc::ast::ast::ImportDeclarationSpecifier::ImportDefaultSpecifier(_) => {
             if let Some(name) = self.get_symbol_final_name(
               (importee.id, importee.cjs_symbols[&Atom::new_inline("default")].symbol).into(),
             ) {
-              self.source.prepend_right(
-                decl.span.start,
-                format!("var {name} = {namespace_name}.default;\n"),
-              );
+              self.source.append_right(start, format!("var {name} = {namespace_name}.default;\n"));
             }
           }
           oxc::ast::ast::ImportDeclarationSpecifier::ImportNamespaceSpecifier(_) => {}
         });
       } else if let Some(wrap_symbol) = importee.wrap_symbol {
         let wrap_symbol_name = self.get_symbol_final_name(wrap_symbol).unwrap();
         // init wrapped esm module
-        self.source.prepend_left(decl.span.start, format!("{wrap_symbol_name}();\n"));
+        self.source.append_right(start, format!("{wrap_symbol_name}();\n"));
       }
     }
   }
@@ -226,4 +225,11 @@ impl<'ast> RendererContext<'ast> {
       }
     }
   }
+
+  fn visit_statement(&mut self, stmt: &'ast oxc::ast::ast::Statement<'ast>) {
+    if !matches!(stmt, oxc::ast::ast::Statement::Declaration(_)) && self.first_stmt_start.is_none()
+    {
+      self.first_stmt_start = Some(stmt.span().start);
+    }
+  }
 }

crates/rolldown/tests/esbuild/default/es6_from_common_js/artifacts.snap

@@ -0,0 +1,33 @@
+---
+source: crates/rolldown/tests/common/case.rs
+expression: content
+input_file: crates/rolldown/tests/esbuild/default/es6_from_common_js
+---
+# main.js
+
+```js
+// bar.js
+var require_bar = __commonJS({
+'bar.js'(exports, module) {
+exports.bar = function() {
+    return 'bar'
+}
+}
+});
+// foo.js
+var require_foo = __commonJS({
+'foo.js'(exports, module) {
+exports.foo = function() {
+  return 'foo'
+}
+}
+});
+// main.js
+var foo_ns = __toESM(require_foo());
+var foo = foo_ns.foo;
+var bar_ns = __toESM(require_bar());
+var bar = bar_ns.bar;
+
+console.log(foo(), bar())
+ // This should be hoisted
+```

crates/rolldown/tests/esbuild/default/nested_es6_from_common_js/artifacts.snap

@@ -0,0 +1,24 @@
+---
+source: crates/rolldown/tests/common/case.rs
+expression: content
+input_file: crates/rolldown/tests/esbuild/default/nested_es6_from_common_js
+---
+# main.js
+
+```js
+// foo.js
+var require_foo = __commonJS({
+'foo.js'(exports, module) {
+exports.fn = function() {
+  return 123
+}
+}
+});
+// main.js
+var foo_ns = __toESM(require_foo());
+var fn = foo_ns.fn;
+
+(() => {
+    console.log(fn())
+})()
+```

crates/rolldown/tests/fixtures/basic_commonjs/artifacts.snap

@@ -34,9 +34,9 @@ module.exports = value;
 // main.js
 var commonjs_ns = __toESM(require_commonjs$1());
 var _default = commonjs_ns.default;
-
 init_esm();
 
+
 console.log(_default, esm_default_fn, esm_named_var, esm_named_fn, esm_named_class)
 // test commonjs warp symbol deconflict
 const require_commonjs = () => {}

crates/rolldown/tests/fixtures/mix-cjs-esm/artifacts.snap

@@ -34,7 +34,5 @@ const value$1 = 1;
 module.exports = 1;
 const value = 1;
 // main.js
-
-
 var esm_import_cjs_export_ns = __toESM(require_esm_import_cjs_export());
 ```