REF: de-duplicate _compare_other (pandas-dev#54424)

* REF: de-duplicate _compare_other

* mypy fixup

Author: jbrockmendel

pandas/tests/extension/base/ops.py

@@ -206,6 +206,7 @@ def _compare_other(self, ser: pd.Series, data, op, other):
             # comparison should match point-wise comparisons
             result = op(ser, other)
             expected = ser.combine(other, op)
+            expected = self._cast_pointwise_result(op.__name__, ser, other, expected)
             tm.assert_series_equal(result, expected)
 
         else:
@@ -218,6 +219,9 @@ def _compare_other(self, ser: pd.Series, data, op, other):
             if exc is None:
                 # Didn't error, then should match pointwise behavior
                 expected = ser.combine(other, op)
+                expected = self._cast_pointwise_result(
+                    op.__name__, ser, other, expected
+                )
                 tm.assert_series_equal(result, expected)
             else:
                 with pytest.raises(type(exc)):
@@ -229,7 +233,7 @@ def test_compare_scalar(self, data, comparison_op):
 
     def test_compare_array(self, data, comparison_op):
         ser = pd.Series(data)
-        other = pd.Series([data[0]] * len(data))
+        other = pd.Series([data[0]] * len(data), dtype=data.dtype)
         self._compare_other(ser, data, comparison_op, other)
 
 

pandas/tests/extension/json/test_json.py

@@ -315,7 +315,11 @@ def test_arith_frame_with_scalar(self, data, all_arithmetic_operators, request):
 
 
 class TestComparisonOps(BaseJSON, base.BaseComparisonOpsTests):
-    pass
+    def test_compare_array(self, data, comparison_op, request):
+        if comparison_op.__name__ in ["eq", "ne"]:
+            mark = pytest.mark.xfail(reason="Comparison methods not implemented")
+            request.node.add_marker(mark)
+        super().test_compare_array(data, comparison_op)
 
 
 class TestPrinting(BaseJSON, base.BasePrintingTests):

pandas/tests/extension/test_arrow.py

@@ -1155,19 +1155,7 @@ def test_compare_array(self, data, comparison_op, na_value):
             tm.assert_series_equal(result, expected)
 
         else:
-            exc = None
-            try:
-                result = comparison_op(ser, other)
-            except Exception as err:
-                exc = err
-
-            if exc is None:
-                # Didn't error, then should match point-wise behavior
-                expected = ser.combine(other, comparison_op)
-                tm.assert_series_equal(result, expected)
-            else:
-                with pytest.raises(type(exc)):
-                    ser.combine(other, comparison_op)
+            return super().test_compare_array(data, comparison_op)
 
     def test_invalid_other_comp(self, data, comparison_op):
         # GH 48833

pandas/tests/extension/test_categorical.py

@@ -267,20 +267,12 @@ def test_arith_series_with_scalar(self, data, all_arithmetic_operators, request)
 class TestComparisonOps(base.BaseComparisonOpsTests):
     def _compare_other(self, s, data, op, other):
         op_name = f"__{op.__name__}__"
-        if op_name == "__eq__":
-            result = op(s, other)
-            expected = s.combine(other, lambda x, y: x == y)
-            assert (result == expected).all()
-
-        elif op_name == "__ne__":
-            result = op(s, other)
-            expected = s.combine(other, lambda x, y: x != y)
-            assert (result == expected).all()
-
-        else:
+        if op_name not in ["__eq__", "__ne__"]:
             msg = "Unordered Categoricals can only compare equality or not"
             with pytest.raises(TypeError, match=msg):
                 op(data, other)
+        else:
+            return super()._compare_other(s, data, op, other)
 
     @pytest.mark.parametrize(
         "categories",

pandas/tests/extension/test_masked_numeric.py

@@ -177,10 +177,6 @@ class TestComparisonOps(base.BaseComparisonOpsTests):
     def _cast_pointwise_result(self, op_name: str, obj, other, pointwise_result):
         return pointwise_result.astype("boolean")
 
-    def _compare_other(self, ser: pd.Series, data, op, other):
-        op_name = f"__{op.__name__}__"
-        self.check_opname(ser, op_name, other)
-
 
 class TestInterface(base.BaseInterfaceTests):
     pass

pandas/tests/extension/test_string.py

@@ -190,12 +190,15 @@ class TestCasting(base.BaseCastingTests):
 
 
 class TestComparisonOps(base.BaseComparisonOpsTests):
-    def _compare_other(self, ser, data, op, other):
-        op_name = f"__{op.__name__}__"
-        result = getattr(ser, op_name)(other)
-        dtype = "boolean[pyarrow]" if ser.dtype.storage == "pyarrow" else "boolean"
-        expected = getattr(ser.astype(object), op_name)(other).astype(dtype)
-        tm.assert_series_equal(result, expected)
+    def _cast_pointwise_result(self, op_name: str, obj, other, pointwise_result):
+        dtype = tm.get_dtype(obj)
+        # error: Item "dtype[Any]" of "dtype[Any] | ExtensionDtype" has no
+        # attribute "storage"
+        if dtype.storage == "pyarrow":  # type: ignore[union-attr]
+            cast_to = "boolean[pyarrow]"
+        else:
+            cast_to = "boolean"
+        return pointwise_result.astype(cast_to)
 
     def test_compare_scalar(self, data, comparison_op):
         ser = pd.Series(data)