Add assertions for UUID extension type in tests

Ensure collected UUID results are extension arrays or chunked arrays
with the UUID extension type before comparison to expected values,
preserving end-to-end metadata validation.

Author: kosiew

python/tests/test_udf.py

@@ -184,7 +184,10 @@ def ensure_extension(values: pa.Array) -> pa.Array:
 
     expected = uuid_type.wrap_array(storage)
 
-    if isinstance(result, pa.Array) and result.type.equals(uuid_type.storage_type):
-        result = uuid_type.wrap_array(result)
+    if isinstance(result, pa.ChunkedArray):
+        assert result.type.equals(uuid_type)
+    else:
+        assert isinstance(result, pa.ExtensionArray)
+        assert result.type.equals(uuid_type)
 
     assert result.equals(expected)