Fix memory leak issue caused by reference cycle

core/src/chunk.rs

@@ -181,6 +181,11 @@ impl Chunk {
 
     next_chunk
   }
+
+  pub(crate) fn clear(&mut self) {
+    self.next = None;
+    self.prev = None;
+  }
 }
 
 impl ToString for Chunk {

core/src/magic_string.rs

@@ -811,3 +811,21 @@ impl ToString for MagicString {
     format!("{}{}", str, self.outro)
   }
 }
+
+impl Drop for MagicString {
+  fn drop(&mut self) {
+    // explicitly clear Rc RefCell cyclic references by setting them to
+    // None before dropping to avoid memory leak caused by reference cycles
+    self.last_chunk.borrow_mut().clear();
+    self.first_chunk.borrow_mut().clear();
+    self.last_searched_chunk.borrow_mut().clear();
+    self
+      .chunk_by_end
+      .iter_mut()
+      .for_each(|v| v.1.borrow_mut().clear());
+    self
+      .chunk_by_start
+      .iter_mut()
+      .for_each(|v| v.1.borrow_mut().clear());
+  }
+}