From 01cc510fb13460c653db6c92ff63f82f95977309 Mon Sep 17 00:00:00 2001
From: Steven Normore <snormore@gmail.com>
Date: Thu, 25 Apr 2024 12:03:57 -0400
Subject: [PATCH] test: add case for borrow extend across scopes

---
 src/lib.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index 53eb742..1f509db 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -187,6 +187,25 @@ mod tests {
 
     use super::*;
 
+    #[test]
+    fn test_owned_ref_cell_extend_borrow_across_scopes() {
+        let cell = OwnedRefCell::new(10);
+
+        // Function that extends the mutable borrow across its original scope
+        fn extend_borrow<T>(mut borrow: OwnedRefMut<T>, modifier: T) -> OwnedRefMut<T>
+        where
+            T: std::ops::AddAssign,
+        {
+            *borrow += modifier;
+            borrow
+        }
+
+        let borrow_mut = cell.borrow_mut();
+        let extended_borrow = extend_borrow(borrow_mut, 5);
+
+        assert_eq!(*extended_borrow, 15);
+    }
+
     #[test]
     fn borrow_mut_modify_and_borrow_after_drop() {
         let cell = OwnedRefCell::new(10);