more tests

Signed-off-by: Adam Gutglick <adam@spiraldb.com>

Author: AdamGS

encodings/parquet-variant/src/vtable.rs

@@ -360,6 +360,7 @@ mod tests {
     use vortex_array::serde::ArrayParts;
     use vortex_array::serde::SerializeOptions;
     use vortex_array::session::ArraySessionExt;
+    use vortex_buffer::BitBuffer;
     use vortex_buffer::ByteBufferMut;
     use vortex_buffer::buffer;
     use vortex_session::VortexSession;
@@ -414,6 +415,26 @@ mod tests {
         assert_eq!(typed.dtype(), &DType::Variant(Nullability::Nullable));
     }
 
+    #[test]
+    fn test_serde_roundtrip_with_nullable_validity() {
+        let metadata =
+            VarBinViewArray::from_iter_bin([b"\x01\x00", b"\x01\x00", b"\x01\x00"]).into_array();
+        let value = VarBinViewArray::from_iter_bin([b"\x10", b"\x11", b"\x12"]).into_array();
+        let validity =
+            vortex_array::validity::Validity::from(BitBuffer::from_iter([true, false, true]));
+
+        let pv = ParquetVariantArray::try_new_with_validity(validity, metadata, Some(value), None)
+            .unwrap();
+        let array = pv.into_array();
+        let decoded = roundtrip(array.clone());
+
+        assert!(array.array_eq(&decoded, Precision::Value));
+        assert_eq!(decoded.dtype(), &DType::Variant(Nullability::Nullable));
+        let decoded_pv = decoded.as_opt::<ParquetVariant>().unwrap();
+        assert!(decoded_pv.value_array().is_some());
+        assert!(decoded_pv.typed_value_array().is_none());
+    }
+
     #[test]
     fn test_serde_roundtrip_typed_value_int32() {
         let outer_metadata =