From ee627c355c919d1b0ce424d5c46c6882159f3f6e Mon Sep 17 00:00:00 2001
From: Dunqing <29533304+Dunqing@users.noreply.github.com>
Date: Tue, 18 Jun 2024 03:40:45 +0000
Subject: [PATCH] feat(isolated-declarations): create unique name for
 `_default` (#3730)

---
 crates/oxc_isolated_declarations/src/module.rs | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/crates/oxc_isolated_declarations/src/module.rs b/crates/oxc_isolated_declarations/src/module.rs
index e45db55c1087e..6898eabc748e1 100644
--- a/crates/oxc_isolated_declarations/src/module.rs
+++ b/crates/oxc_isolated_declarations/src/module.rs
@@ -3,7 +3,7 @@ use oxc_ast::ast::*;
 
 use oxc_allocator::Box;
 use oxc_ast::Visit;
-use oxc_span::{GetSpan, SPAN};
+use oxc_span::{Atom, GetSpan, SPAN};
 
 use crate::{diagnostics::default_export_inferred, IsolatedDeclarations};
 
@@ -24,6 +24,16 @@ impl<'a> IsolatedDeclarations<'a> {
         })
     }
 
+    pub fn create_unique_name(&mut self, name: &str) -> Atom<'a> {
+        let mut binding = self.ast.new_atom(name);
+        let mut i = 1;
+        while self.scope.has_reference(&binding) {
+            binding = self.ast.new_atom(format!("{name}_{i}").as_str());
+            i += 1;
+        }
+        binding
+    }
+
     pub fn transform_export_default_declaration(
         &mut self,
         decl: &ExportDefaultDeclaration<'a>,
@@ -46,8 +56,7 @@ impl<'a> IsolatedDeclarations<'a> {
                 } else {
                     // declare const _default: Type
                     let kind = VariableDeclarationKind::Const;
-                    // TODO: create unique name for this
-                    let name = self.ast.new_atom("_default");
+                    let name = self.create_unique_name("_default");
                     let id = self
                         .ast
                         .binding_pattern_identifier(BindingIdentifier::new(SPAN, name.clone()));