Fix warnings with attrs 19.2 and fix object assertions

src/_pytest/assertion/util.py

@@ -8,6 +8,7 @@
 import _pytest._code
 from _pytest import outcomes
 from _pytest._io.saferepr import saferepr
+from _pytest.compat import ATTRS_EQ_FIELD
 
 # The _reprcompare attribute on the util module is used by the new assertion
 # interpretation code and assertion rewriter to detect this plugin was
@@ -375,7 +376,9 @@ def _compare_eq_cls(left, right, verbose, type_fns):
  fields_to_check = [field for field, info in all_fields.items() if info.compare]
  elif isattrs(left):
  all_fields = left.__attrs_attrs__
- fields_to_check = [field.name for field in all_fields if field.cmp]
+ fields_to_check = [
+ field.name for field in all_fields if getattr(field, ATTRS_EQ_FIELD)
+ ]
 
  same = []
  diff = []

src/_pytest/compat.py

@@ -354,3 +354,9 @@ def funcargnames(self):
 
  def overload(f): # noqa: F811
  return f
+
+
+if getattr(attr, "__version_info__", ()) >= (19, 2):
+ ATTRS_EQ_FIELD = "eq"
+else:
+ ATTRS_EQ_FIELD = "cmp"

src/_pytest/mark/structures.py

@@ -8,6 +8,7 @@
 import attr
 
 from ..compat import ascii_escaped
+from ..compat import ATTRS_EQ_FIELD
 from ..compat import getfslineno
 from ..compat import NOTSET
 from _pytest.outcomes import fail
@@ -367,7 +368,8 @@ def __repr__(self):
  return "<NodeKeywords for node {}>".format(self.node)
 
 
-@attr.s(cmp=False, hash=False)
+# mypy cannot find this overload, remove when on attrs>=19.2
+@attr.s(hash=False, **{ATTRS_EQ_FIELD: False}) # type: ignore
 class NodeMarkers:
  """
  internal structure for storing marks belonging to a node

testing/test_assertion.py

@@ -9,6 +9,7 @@
 from _pytest import outcomes
 from _pytest.assertion import truncate
 from _pytest.assertion import util
+from _pytest.compat import ATTRS_EQ_FIELD
 
 
 def mock_config():
@@ -687,7 +688,7 @@ def test_attrs_with_attribute_comparison_off(self):
  @attr.s
  class SimpleDataObject:
  field_a = attr.ib()
- field_b = attr.ib(cmp=False)
+ field_b = attr.ib(**{ATTRS_EQ_FIELD: False})
 
  left = SimpleDataObject(1, "b")
  right = SimpleDataObject(1, "b")