add the test case for grouping bug

Author: asharmalik19

pandas/tests/groupby/test_groupby.py

@@ -4,11 +4,14 @@
 import re
 
 import numpy as np
+import pyarrow as pa
 import pytest
 
 from pandas.errors import SpecificationError
 import pandas.util._test_decorators as td
 
+from pandas.core.dtypes.dtypes import ArrowDtype
+
 import pandas as pd
 from pandas import (
     Categorical,
@@ -2978,3 +2981,21 @@ def test_groupby_multi_index_codes():
 
     index = df_grouped.index
     tm.assert_index_equal(index, MultiIndex.from_frame(index.to_frame()))
+
+
+def test_groupby_arrow_dictionary_na():
+    # Arrange
+    df = DataFrame(
+        {"A": ["a1", pd.NA]}, dtype=ArrowDtype(pa.dictionary(pa.int32(), pa.utf8()))
+    )
+
+    # Act
+    result = df.groupby("A", dropna=False)[["A"]].first()
+
+    # Assert
+    expected = DataFrame(
+        {"A": ["a1", pd.NA]},
+        index=Index(["a1", pd.NA], name="A"),
+        dtype=ArrowDtype(pa.dictionary(pa.int32(), pa.utf8())),
+    )
+    tm.assert_frame_equal(result, expected)