From 4ca9ac83d2b103566d9b053e79b3a787b8ebf7f8 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Tue, 20 Feb 2024 05:13:14 -1000
Subject: [PATCH] Change chained replace inplace test to COW test for pandas
 2.2 (#15049)

`test_setitem_dataframe_series_inplace` failed with pandas 2.2 because it exhibits a chained indexing behavior that raised a `FutureWarning` in pandas 2.2 and will raise in 3.0. I refactored the test to test cudf copy on write to exhibit the 3.0 behavior, but it still seems to allow this chained indexing behavior, so xfailed it for now.

Authors:
  - Matthew Roeschke (https://github.com/mroeschke)

Approvers:
  - GALI PREM SAGAR (https://github.com/galipremsagar)

URL: https://github.com/rapidsai/cudf/pull/15049
---
 python/cudf/cudf/tests/test_setitem.py | 33 +++++++++-----------------
 1 file changed, 11 insertions(+), 22 deletions(-)

diff --git a/python/cudf/cudf/tests/test_setitem.py b/python/cudf/cudf/tests/test_setitem.py
index de0826d61e9..967c1d27fc1 100644
--- a/python/cudf/cudf/tests/test_setitem.py
+++ b/python/cudf/cudf/tests/test_setitem.py
@@ -118,34 +118,23 @@ def test_series_setitem_singleton_range():
     assert_eq(sr, psr, check_dtype=True)
 
 
+@pytest.mark.xfail(reason="Copy-on-Write should make a copy")
 @pytest.mark.parametrize(
-    "df",
+    "index",
     [
-        pd.DataFrame(
-            {"a": [1, 2, 3]},
-            index=pd.MultiIndex.from_frame(
-                pd.DataFrame({"b": [3, 2, 1], "c": ["a", "b", "c"]})
-            ),
+        pd.MultiIndex.from_frame(
+            pd.DataFrame({"b": [3, 2, 1], "c": ["a", "b", "c"]})
         ),
-        pd.DataFrame({"a": [1, 2, 3]}, index=["a", "b", "c"]),
+        ["a", "b", "c"],
     ],
 )
-def test_setitem_dataframe_series_inplace(df):
-    pdf = df.copy(deep=True)
-    gdf = cudf.from_pandas(pdf)
-
-    pdf["a"].replace(1, 500, inplace=True)
-    gdf["a"].replace(1, 500, inplace=True)
-
-    assert_eq(pdf, gdf)
-
-    psr_a = pdf["a"]
-    gsr_a = gdf["a"]
-
-    psr_a.replace(500, 501, inplace=True)
-    gsr_a.replace(500, 501, inplace=True)
+def test_setitem_dataframe_series_inplace(index):
+    gdf = cudf.DataFrame({"a": [1, 2, 3]}, index=index)
+    expected = gdf.copy()
+    with cudf.option_context("copy_on_write", True):
+        gdf["a"].replace(1, 500, inplace=True)
 
-    assert_eq(pdf, gdf)
+    assert_eq(expected, gdf)
 
 
 @pytest.mark.parametrize(