fix: should correctly render export default xxx (#377)

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

@@ -6,7 +6,7 @@ mod utils;
 use std::fmt::Debug;
 
 use oxc::{
-  ast::Visit,
+  ast::{ast::Expression, Visit},
   span::{Atom, GetSpan, Span},
 };
 use rolldown_common::{ExportsKind, StmtInfo, StmtInfoId, StmtInfos, SymbolRef, WrapKind};
@@ -189,20 +189,27 @@ impl<'r> AstRenderer<'r> {
     }
   }
 
+  // hyf0: clippy::single_match_else: using match statement is more readable
+  #[allow(clippy::single_match_else)]
   fn strip_export_keyword(
     &mut self,
     default_decl: &oxc::ast::ast::ExportDefaultDeclaration,
   ) -> RenderControl {
     match &default_decl.declaration {
-      oxc::ast::ast::ExportDefaultDeclarationKind::Expression(exp) => {
-        let default_ref_name = self.ctx.default_ref_name.expect("Should generated a name");
-        self.ctx.source.overwrite(
-          default_decl.span.start,
-          exp.span().start,
-          format!("var {default_ref_name} = "),
-        );
-        self.visit_expression(exp);
-      }
+      oxc::ast::ast::ExportDefaultDeclarationKind::Expression(exp) => match exp {
+        Expression::Identifier(_) => {
+          self.ctx.remove_node(default_decl.span);
+        }
+        _ => {
+          let default_ref_name = self.ctx.default_ref_name.expect("Should generated a name");
+          self.ctx.source.overwrite(
+            default_decl.span.start,
+            exp.span().start,
+            format!("var {default_ref_name} = "),
+          );
+          self.visit_expression(exp);
+        }
+      },
       oxc::ast::ast::ExportDefaultDeclarationKind::FunctionDeclaration(decl) => {
         self.ctx.remove_node(Span::new(default_decl.span.start, decl.span.start));
       }

crates/rolldown/tests/fixtures/misc/issue_376/_test.mjs

@@ -0,0 +1,3 @@
+import assert from 'node:assert'
+import main from './dist/main.mjs'
+assert.equal(main, 'hello world')

crates/rolldown/tests/fixtures/misc/issue_376/artifacts.snap

@@ -0,0 +1,17 @@
+---
+source: crates/rolldown/tests/common/case.rs
+expression: content
+input_file: crates/rolldown/tests/fixtures/misc/issue_376
+---
+# Assets
+
+## main.mjs
+
+```js
+// main.js
+const test = 'hello world'
+
+
+
+export { test as default };
+```

crates/rolldown/tests/fixtures/misc/issue_376/main.js

@@ -0,0 +1,3 @@
+const test = 'hello world'
+
+export default test

crates/rolldown/tests/fixtures/misc/issue_376/test.config.json

@@ -0,0 +1 @@
+{}