test: add test_iter_returns_datafusion_recordbatch to verify RecordBatch type

Author: kosiew

python/tests/test_dataframe.py

@@ -45,6 +45,7 @@
     reset_formatter,
 )
 from datafusion.expr import Window
+from datafusion.record_batch import RecordBatch as DataFusionRecordBatch
 from pyarrow.csv import write_csv
 
 pa_cffi = pytest.importorskip("pyarrow.cffi")
@@ -398,6 +399,11 @@ def test_iter_batches(df):
     assert pa_batch.column(2).to_pylist() == [8, 5, 8]
 
 
+def test_iter_returns_datafusion_recordbatch(df):
+    for batch in df:
+        assert isinstance(batch, DataFusionRecordBatch)
+
+
 def test_to_record_batch_stream(df):
     stream = df.to_record_batch_stream()
     batches = list(stream)