BUG: assert_series_equal not properly respecting check-dtype (pandas-dev#56654)

Author: phofl

pandas/_testing/asserters.py

@@ -949,9 +949,15 @@ def assert_series_equal(
                 obj=str(obj),
             )
         else:
+            # convert both to NumPy if not, check_dtype would raise earlier
+            lv, rv = left_values, right_values
+            if isinstance(left_values, ExtensionArray):
+                lv = left_values.to_numpy()
+            if isinstance(right_values, ExtensionArray):
+                rv = right_values.to_numpy()
             assert_numpy_array_equal(
-                left_values,
-                right_values,
+                lv,
+                rv,
                 check_dtype=check_dtype,
                 obj=str(obj),
                 index_values=left.index,

pandas/tests/extension/test_numpy.py

@@ -421,16 +421,6 @@ def test_index_from_listlike_with_dtype(self, data):
     def test_EA_types(self, engine, data, request):
         super().test_EA_types(engine, data, request)
 
-    @pytest.mark.xfail(reason="Expect NumpyEA, get np.ndarray")
-    def test_compare_array(self, data, comparison_op):
-        super().test_compare_array(data, comparison_op)
-
-    def test_compare_scalar(self, data, comparison_op, request):
-        if data.dtype.kind == "f" or comparison_op.__name__ in ["eq", "ne"]:
-            mark = pytest.mark.xfail(reason="Expect NumpyEA, get np.ndarray")
-            request.applymarker(mark)
-        super().test_compare_scalar(data, comparison_op)
-
 
 class Test2DCompat(base.NDArrayBacked2DTests):
     pass

pandas/tests/util/test_assert_frame_equal.py

@@ -211,10 +211,7 @@ def test_assert_frame_equal_extension_dtype_mismatch():
         "\\[right\\]: int[32|64]"
     )
 
-    # TODO: this shouldn't raise (or should raise a better error message)
-    # https://github.com/pandas-dev/pandas/issues/56131
-    with pytest.raises(AssertionError, match="classes are different"):
-        tm.assert_frame_equal(left, right, check_dtype=False)
+    tm.assert_frame_equal(left, right, check_dtype=False)
 
     with pytest.raises(AssertionError, match=msg):
         tm.assert_frame_equal(left, right, check_dtype=True)
@@ -246,7 +243,6 @@ def test_assert_frame_equal_ignore_extension_dtype_mismatch():
     tm.assert_frame_equal(left, right, check_dtype=False)
 
 
-@pytest.mark.xfail(reason="https://github.com/pandas-dev/pandas/issues/56131")
 def test_assert_frame_equal_ignore_extension_dtype_mismatch_cross_class():
     # https://github.com/pandas-dev/pandas/issues/35715
     left = DataFrame({"a": [1, 2, 3]}, dtype="Int64")
@@ -300,9 +296,7 @@ def test_frame_equal_mixed_dtypes(frame_or_series, any_numeric_ea_dtype, indexer
     dtypes = (any_numeric_ea_dtype, "int64")
     obj1 = frame_or_series([1, 2], dtype=dtypes[indexer[0]])
     obj2 = frame_or_series([1, 2], dtype=dtypes[indexer[1]])
-    msg = r'(Series|DataFrame.iloc\[:, 0\] \(column name="0"\) classes) are different'
-    with pytest.raises(AssertionError, match=msg):
-        tm.assert_equal(obj1, obj2, check_exact=True, check_dtype=False)
+    tm.assert_equal(obj1, obj2, check_exact=True, check_dtype=False)
 
 
 def test_assert_frame_equal_check_like_different_indexes():

pandas/tests/util/test_assert_series_equal.py

@@ -290,10 +290,7 @@ def test_assert_series_equal_extension_dtype_mismatch():
 \\[left\\]:  Int64
 \\[right\\]: int[32|64]"""
 
-    # TODO: this shouldn't raise (or should raise a better error message)
-    # https://github.com/pandas-dev/pandas/issues/56131
-    with pytest.raises(AssertionError, match="Series classes are different"):
-        tm.assert_series_equal(left, right, check_dtype=False)
+    tm.assert_series_equal(left, right, check_dtype=False)
 
     with pytest.raises(AssertionError, match=msg):
         tm.assert_series_equal(left, right, check_dtype=True)
@@ -372,7 +369,6 @@ def test_assert_series_equal_ignore_extension_dtype_mismatch():
     tm.assert_series_equal(left, right, check_dtype=False)
 
 
-@pytest.mark.xfail(reason="https://github.com/pandas-dev/pandas/issues/56131")
 def test_assert_series_equal_ignore_extension_dtype_mismatch_cross_class():
     # https://github.com/pandas-dev/pandas/issues/35715
     left = Series([1, 2, 3], dtype="Int64")
@@ -456,3 +452,13 @@ def test_large_unequal_ints(dtype):
     right = Series([1577840521123543], dtype=dtype)
     with pytest.raises(AssertionError, match="Series are different"):
         tm.assert_series_equal(left, right)
+
+
+@pytest.mark.parametrize("dtype", [None, object])
+@pytest.mark.parametrize("check_exact", [True, False])
+@pytest.mark.parametrize("val", [3, 3.5])
+def test_ea_and_numpy_no_dtype_check(val, check_exact, dtype):
+    # GH#56651
+    left = Series([1, 2, val], dtype=dtype)
+    right = Series(pd.array([1, 2, val]))
+    tm.assert_series_equal(left, right, check_dtype=False, check_exact=check_exact)