Retain series name in Series.apply (#10716)

Closes #10715

Authors:
  - https://github.com/brandon-b-miller

Approvers:
  - Ashwin Srinath (https://github.com/shwina)
  - Bradley Dice (https://github.com/bdice)

URL: #10716

python/cudf/cudf/core/series.py

@@ -2110,7 +2110,10 @@ def apply(self, func, convert_dtype=True, args=(), **kwargs):
         """
         if convert_dtype is not True:
             raise ValueError("Series.apply only supports convert_dtype=True")
-        return self._apply(func, _get_scalar_kernel, *args, **kwargs)
+
+        result = self._apply(func, _get_scalar_kernel, *args, **kwargs)
+        result.name = self.name
+        return result
 
     @_cudf_nvtx_annotate
     def applymap(self, udf, out_dtype=None):

python/cudf/cudf/tests/test_udf_masked_ops.py

@@ -367,9 +367,12 @@ def func(row):
 
 
 @pytest.mark.parametrize(
-    "data", [cudf.Series([1, 2, 3]), cudf.Series([1, cudf.NA, 3])]
+    "data,name",
+    [([1, 2, 3], None), ([1, cudf.NA, 3], None), ([1, 2, 3], "test_name")],
 )
-def test_series_apply_basic(data):
+def test_series_apply_basic(data, name):
+    data = cudf.Series(data, name=name)
+
     def func(x):
         return x + 1