TST(str dtype): Resolve xfail for unary +

Author: rhshadrach

pandas/core/arrays/string_arrow.py

@@ -4,6 +4,7 @@
 import re
 from typing import (
     TYPE_CHECKING,
+    Never,
     Union,
 )
 import warnings
@@ -481,6 +482,9 @@ def _cmp_method(self, other, op):
                 return result.to_numpy(np.bool_, na_value=False)
         return result
 
+    def __pos__(self) -> Never:
+        raise TypeError(f"bad operand type for unary +: '{self.dtype}'")
+
 
 class ArrowStringArrayNumpySemantics(ArrowStringArray):
     _na_value = np.nan

pandas/tests/frame/test_unary.py

@@ -3,9 +3,6 @@
 import numpy as np
 import pytest
 
-from pandas._config import using_string_dtype
-
-from pandas.compat import HAS_PYARROW
 from pandas.compat.numpy import np_version_gte1p25
 
 import pandas as pd
@@ -122,9 +119,6 @@ def test_pos_object(self, df_data):
         tm.assert_frame_equal(+df, df)
         tm.assert_series_equal(+df["a"], df["a"])
 
-    @pytest.mark.xfail(
-        using_string_dtype() and HAS_PYARROW, reason="TODO(infer_string)"
-    )
     @pytest.mark.filterwarnings("ignore:Applying:DeprecationWarning")
     def test_pos_object_raises(self):
         # GH#21380