Unit test for groupby.rolling.corr (#54499)

Author: omar-elbaz

pandas/tests/groupby/test_groupby.py

@@ -3159,3 +3159,29 @@ def test_groupby_series_with_datetimeindex_month_name():
     expected = Series([2, 1], name="jan")
     expected.index.name = "jan"
     tm.assert_series_equal(result, expected)
+
+
+def test_rolling_corr_grouping_column_contains_tuples_1(df):
+    # GH 44078
+    df = DataFrame({"a": [(1,), (1,), (1,)], "b": [4, 5, 6]})
+    gb = df.groupby(["a"])
+    result = gb.rolling(2).corr(other=df)
+    index = MultiIndex.from_tuples([((1,), 0), ((1,), 1), ((1,), 2)], names=["a", None])
+    expected = DataFrame(
+        {"a": [np.nan, np.nan, np.nan], "b": [np.nan, 1.0, 1.0]}, index=index
+    )
+    tm.assert_frame_equal(result, expected)
+
+
+def test_rolling_corr_case_grrouping_column_contains_tuples_2(df):
+    # GH 44078
+    df = DataFrame({"a": [(1, 2), (1, 2), (1, 2)], "b": [4, 5, 6]})
+    gb = df.groupby(["a"])
+    result = gb.rolling(2).corr(other=df)
+    index = MultiIndex.from_tuples(
+        [((1, 2), 0), ((1, 2), 1), ((1, 2), 2)], names=["a", None]
+    )
+    expected = DataFrame(
+        {"a": [np.nan, np.nan, np.nan], "b": [np.nan, 1.0, 1.0]}, index=index
+    )
+    tm.assert_frame_equal(result, expected)