Add Entry test

Author: tfreiberg-fastly

src/mapref/entry.rs

@@ -214,6 +214,42 @@ mod tests {
 
     use super::*;
 
+    #[test]
+    fn test_insert_into_vacant() {
+        let map: DashMap<u32, u32> = DashMap::new();
+
+        let entry = map.entry(1);
+
+        assert!(matches!(entry, Entry::Vacant(_)));
+
+        let val = entry.insert(2);
+
+        assert_eq!(*val, 2);
+
+        drop(val);
+
+        assert_eq!(*map.get(&1).unwrap(), 2);
+    }
+
+    #[test]
+    fn test_insert_into_occupied() {
+        let map: DashMap<u32, u32> = DashMap::new();
+
+        map.insert(1, 1000);
+
+        let entry = map.entry(1);
+
+        assert!(matches!(&entry, Entry::Occupied(entry) if *entry.get() == 1000));
+
+        let val = entry.insert(2);
+
+        assert_eq!(*val, 2);
+
+        drop(val);
+
+        assert_eq!(*map.get(&1).unwrap(), 2);
+    }
+
     #[test]
     fn test_insert_entry_into_vacant() {
         let map: DashMap<u32, u32> = DashMap::new();