BUG: fix Series(extension array) + extension array values addition (pandas-dev#22479)

Author: peterpanmj

pandas/core/ops.py

@@ -1218,7 +1218,7 @@ def dispatch_to_extension_op(op, left, right):
                 new_right = [new_right]
             new_right = list(new_right)
         elif is_extension_array_dtype(right) and type(left) != type(right):
-            new_right = list(new_right)
+            new_right = list(right)
         else:
             new_right = right
 

pandas/tests/extension/base/ops.py

@@ -77,6 +77,12 @@ def test_divmod(self, data):
         self._check_divmod_op(s, divmod, 1, exc=TypeError)
         self._check_divmod_op(1, ops.rdivmod, s, exc=TypeError)
 
+    def test_add_series_with_extension_array(self, data):
+        s = pd.Series(data)
+        result = s + data
+        expected = pd.Series(data + data)
+        self.assert_series_equal(result, expected)
+
     def test_error(self, data, all_arithmetic_operators):
         # invalid ops
         op_name = all_arithmetic_operators

pandas/tests/extension/json/test_json.py

@@ -261,6 +261,11 @@ class TestArithmeticOps(BaseJSON, base.BaseArithmeticOpsTests):
     def test_error(self, data, all_arithmetic_operators):
         pass
 
+    def test_add_series_with_extension_array(self, data):
+        ser = pd.Series(data)
+        with tm.assert_raises_regex(TypeError, "unsupported"):
+            ser + data
+
 
 class TestComparisonOps(BaseJSON, base.BaseComparisonOpsTests):
     pass

pandas/tests/extension/test_categorical.py

@@ -22,6 +22,7 @@
 from pandas.api.types import CategoricalDtype
 from pandas import Categorical
 from pandas.tests.extension import base
+import pandas.util.testing as tm
 
 
 def make_data():
@@ -202,6 +203,11 @@ def test_arith_series_with_scalar(self, data, all_arithmetic_operators):
         else:
             pytest.skip('rmod never called when string is first argument')
 
+    def test_add_series_with_extension_array(self, data):
+        ser = pd.Series(data)
+        with tm.assert_raises_regex(TypeError, "cannot perform"):
+            ser + data
+
 
 class TestComparisonOps(base.BaseComparisonOpsTests):
 

pandas/tests/extension/test_integer.py

@@ -143,6 +143,12 @@ def test_error(self, data, all_arithmetic_operators):
         # other specific errors tested in the integer array specific tests
         pass
 
+    @pytest.mark.xfail(reason="EA is listified. GH-22922", strict=True)
+    def test_add_series_with_extension_array(self, data):
+        super(TestArithmeticOps, self).test_add_series_with_extension_array(
+            data
+        )
+
 
 class TestComparisonOps(base.BaseComparisonOpsTests):