Add borsh serialization roundtrip tests

Author: sug0

src/borsh.rs

@@ -136,3 +136,32 @@ fn check_zst<T>() -> Result<()> {
     }
     Ok(())
 }
+
+#[cfg(test)]
+mod borsh_tests {
+    use super::*;
+
+    #[test]
+    fn map_borsh_roundtrip() {
+        let original_map: IndexMap<i32, i32> = {
+            let mut map = IndexMap::new();
+            map.insert(1, 2);
+            map.insert(3, 4);
+            map.insert(5, 6);
+            map
+        };
+        let serialized_map = borsh::to_vec(&original_map).unwrap();
+        let deserialized_map: IndexMap<i32, i32> =
+            BorshDeserialize::try_from_slice(&serialized_map).unwrap();
+        assert_eq!(original_map, deserialized_map);
+    }
+
+    #[test]
+    fn set_borsh_roundtrip() {
+        let original_map: IndexSet<i32> = [1, 2, 3, 4, 5, 6].into_iter().collect();
+        let serialized_map = borsh::to_vec(&original_map).unwrap();
+        let deserialized_map: IndexSet<i32> =
+            BorshDeserialize::try_from_slice(&serialized_map).unwrap();
+        assert_eq!(original_map, deserialized_map);
+    }
+}