Add test for empty partitions after groupby

Author: Retribution98

modin/tests/pandas/test_groupby.py

@@ -21,7 +21,13 @@
 import pytest
 
 import modin.pandas as pd
-from modin.config import IsRayCluster, NPartitions, RangePartitioning, StorageFormat
+from modin.config import (
+    DynamicPartitioning,
+    IsRayCluster,
+    NPartitions,
+    RangePartitioning,
+    StorageFormat,
+)
 from modin.core.dataframe.algebra.default2pandas.groupby import GroupBy
 from modin.core.dataframe.pandas.partitioning.axis_partition import (
     PandasDataframeAxisPartition,
@@ -2431,6 +2437,32 @@ def test_multi_column_groupby_different_partitions(
     )
 
 
+def test_empty_partitions_after_groupby():
+    DynamicPartitioning.put(True)
+
+    def func_to_apply(grp):
+        return grp.agg(
+            {
+                list(test_data_values[0].keys())[1]: "sum",
+                list(test_data_values[0].keys())[-1]: "sum",
+            }
+        )
+
+    data = test_data_values[0]
+    md_df, pd_df = create_test_dfs(data)
+    by = pd_df.columns[0]
+
+    md_grp, pd_grp = (
+        md_df.groupby(by),
+        pd_df.groupby(by),
+    )
+    eval_general(
+        md_grp,
+        pd_grp,
+        func_to_apply,
+    )
+
+
 @pytest.mark.parametrize(
     "by",
     [