value: test null and empty

Author: wprzytula

scylla-cql/src/types/deserialize/value.rs

@@ -845,7 +845,7 @@ mod tests {
     use crate::types::serialize::value::SerializeValue;
     use crate::types::serialize::CellWriter;
 
-    use super::{mk_deser_err, BuiltinDeserializationErrorKind, DeserializeValue};
+    use super::{mk_deser_err, BuiltinDeserializationErrorKind, DeserializeValue, MaybeEmpty};
 
     #[test]
     fn test_deserialize_bytes() {
@@ -934,6 +934,34 @@ mod tests {
         assert_eq!(decoded_double, 2.0);
     }
 
+    #[test]
+    fn test_null_and_empty() {
+        // non-nullable emptiable deserialization, non-empty value
+        let int = make_bytes(&[21, 37, 0, 0]);
+        let decoded_int = deserialize::<MaybeEmpty<i32>>(&ColumnType::Int, &int).unwrap();
+        assert_eq!(decoded_int, MaybeEmpty::Value((21 << 24) + (37 << 16)));
+
+        // non-nullable emptiable deserialization, empty value
+        let int = make_bytes(&[]);
+        let decoded_int = deserialize::<MaybeEmpty<i32>>(&ColumnType::Int, &int).unwrap();
+        assert_eq!(decoded_int, MaybeEmpty::Empty);
+
+        // nullable non-emptiable deserialization, non-null value
+        let int = make_bytes(&[21, 37, 0, 0]);
+        let decoded_int = deserialize::<Option<i32>>(&ColumnType::Int, &int).unwrap();
+        assert_eq!(decoded_int, Some((21 << 24) + (37 << 16)));
+
+        // nullable non-emptiable deserialization, null value
+        let int = make_null();
+        let decoded_int = deserialize::<Option<i32>>(&ColumnType::Int, &int).unwrap();
+        assert_eq!(decoded_int, None);
+
+        // nullable emptiable deserialization, non-null non-empty value
+        let int = make_bytes(&[]);
+        let decoded_int = deserialize::<Option<MaybeEmpty<i32>>>(&ColumnType::Int, &int).unwrap();
+        assert_eq!(decoded_int, Some(MaybeEmpty::Empty));
+    }
+
     #[test]
     fn test_from_cql_value_compatibility() {
         // This test should have a sub-case for each type