test: xfail cudf where necessary (#2386)

xfail cudf

Author: MarcoGorelli

tests/expr_and_series/over_test.py

@@ -435,8 +435,9 @@ def test_len_over_2369(constructor: Constructor, request: pytest.FixtureRequest)
         pytest.skip()
     if "pandas" in str(constructor) and PANDAS_VERSION < (1, 5):
         pytest.skip()
-    if any(x in str(constructor) for x in ("modin",)):
+    if any(x in str(constructor) for x in ("modin", "cudf")):
         # https://github.com/modin-project/modin/issues/7508
+        # https://github.com/rapidsai/cudf/issues/18491
         request.applymarker(pytest.mark.xfail)
     df = nw.from_native(constructor({"a": [1, 2, 4], "b": ["x", "x", "y"]}))
     result = df.with_columns(a_len_per_group=nw.len().over("b")).sort("a")

tests/v1_test.py

@@ -138,6 +138,8 @@ def test_to_dict(constructor_eager: ConstructorEager) -> None:
 def test_hist_v1(constructor_eager: ConstructorEager) -> None:
     if "pyarrow_table" in str(constructor_eager) and PYARROW_VERSION < (13,):
         pytest.skip()
+    if "cudf" in str(constructor_eager):
+        pytest.skip()
     df = nw_v1.from_native(constructor_eager({"a": [1, 1, 2]}), eager_only=True)
     result = df["a"].hist(bins=[-1, 1, 2])
     expected = {"breakpoint": [1, 2], "count": [2, 1]}