fix pyarrow round dtypes

Author: andrewgsavage

pandas/core/arrays/arrow/array.py

@@ -1085,7 +1085,8 @@ def round(self, decimals: int = 0, *args, **kwargs) -> Self:
         DataFrame.round : Round values of a DataFrame.
         Series.round : Round values of a Series.
         """
-        return type(self)(pc.round(self._pa_array, ndigits=decimals))
+        result = pc.round(self._pa_array, ndigits=decimals)
+        return type(self)(result.cast(self._pa_array.type))
 
     @doc(ExtensionArray.searchsorted)
     def searchsorted(

pandas/tests/extension/test_arrow.py

@@ -1023,23 +1023,8 @@ def _get_arith_xfail_marker(self, opname, pa_dtype):
                 raises=pa.ArrowInvalid,
                 reason="Invalid decimal function: power_checked",
             )
-
         return mark
 
-    def test_round(self, data, request):
-        mark = None         
-        if not (
-            pa.types.is_float32(data.dtype.pyarrow_dtype)
-            or pa.types.is_float64(data.dtype.pyarrow_dtype)
-            or pa.types.is_decimal(data.dtype.pyarrow_dtype)
-        ):
-            pytest.mark.xfail(
-               reason="ArrowArray.round converts dtype to double",
-        )
-        if mark is not None:
-            request.node.add_marker(mark)
-        super().test_round(data)
-
     def test_arith_series_with_scalar(self, data, all_arithmetic_operators, request):
         pa_dtype = data.dtype.pyarrow_dtype