Restore basic functionality on 3.14[sic] (#1329)

* Restore basic functionality on 3.14[sic]

Essentially switch to PEP 649 / 749 for annotations. Some tests need to
be skipped for now, but the rest is working.

Fixes #1326

* Add news fragment

* We have not 3.14 CI yet

* Use imprerative xfails instead of skips

Author: hynek

changelog.d/1329.change.md

@@ -0,0 +1 @@
+Restored support for PEP [649](https://peps.python.org/pep-0649/) / [749](https://peps.python.org/pep-0749/)-implementing Pythons -- currently 3.14-dev.

src/attr/_compat.py

@@ -15,6 +15,7 @@
 PY_3_10_PLUS = sys.version_info[:2] >= (3, 10)
 PY_3_12_PLUS = sys.version_info[:2] >= (3, 12)
 PY_3_13_PLUS = sys.version_info[:2] >= (3, 13)
+PY_3_14_PLUS = sys.version_info[:2] >= (3, 14)
 
 
 if sys.version_info < (3, 8):
@@ -25,6 +26,19 @@
 else:
     from typing import Protocol  # noqa: F401
 
+if PY_3_14_PLUS:  # pragma: no cover
+    import annotationlib
+
+    _get_annotations = annotationlib.get_annotations
+
+else:
+
+    def _get_annotations(cls):
+        """
+        Get annotations for *cls*.
+        """
+        return cls.__dict__.get("__annotations__", {})
+
 
 class _AnnotationExtractor:
     """

src/attr/_make.py

@@ -23,6 +23,7 @@
     PY_3_8_PLUS,
     PY_3_10_PLUS,
     _AnnotationExtractor,
+    _get_annotations,
     get_generic_base,
 )
 from .exceptions import (
@@ -308,13 +309,6 @@ def _has_own_attribute(cls, attrib_name):
     return attrib_name in cls.__dict__
 
 
-def _get_annotations(cls):
-    """
-    Get annotations for *cls*.
-    """
-    return cls.__dict__.get("__annotations__", {})
-
-
 def _collect_base_attrs(cls, taken_attr_names):
     """
     Collect attr.ibs from base classes of *cls*, except *taken_attr_names*.

tests/test_3rd_party.py

@@ -8,12 +8,17 @@
 
 from hypothesis import given
 
+from attr._compat import PY_3_14_PLUS
+
 from .strategies import simple_classes
 
 
 cloudpickle = pytest.importorskip("cloudpickle")
 
 
+@pytest.mark.xfail(
+    PY_3_14_PLUS, reason="cloudpickle is currently broken on 3.14."
+)
 class TestCloudpickleCompat:
     """
     Tests for compatibility with ``cloudpickle``.

tests/test_annotations.py

@@ -12,6 +12,7 @@
 
 import attr
 
+from attr._compat import PY_3_14_PLUS
 from attr._make import _is_class_var
 from attr.exceptions import UnannotatedAttributeError
 
@@ -588,6 +589,8 @@ def test_self_reference(self, slots):
         """
         References to self class using quotes can be resolved.
         """
+        if PY_3_14_PLUS and not slots:
+            pytest.xfail("References are changing a lot in 3.14.")
 
         @attr.s(slots=slots, auto_attribs=True)
         class A:
@@ -603,6 +606,8 @@ def test_forward_reference(self, slots):
         """
         Forward references can be resolved.
         """
+        if PY_3_14_PLUS and not slots:
+            pytest.xfail("Forward references are changing a lot in 3.14.")
 
         @attr.s(slots=slots, auto_attribs=True)
         class A:

tests/test_make.py

@@ -21,7 +21,7 @@
 import attr
 
 from attr import _config
-from attr._compat import PY_3_8_PLUS, PY_3_10_PLUS
+from attr._compat import PY_3_8_PLUS, PY_3_10_PLUS, PY_3_14_PLUS
 from attr._make import (
     Attribute,
     Factory,
@@ -1838,9 +1838,11 @@ class C2(C):
         assert [C2] == C.__subclasses__()
 
     @pytest.mark.skipif(not PY_3_8_PLUS, reason="cached_property is 3.8+")
+    @pytest.mark.xfail(PY_3_14_PLUS, reason="Currently broken on nightly.")
     def test_no_references_to_original_when_using_cached_property(self):
         """
-        When subclassing a slotted class and using cached property, there are no stray references to the original class.
+        When subclassing a slotted class and using cached property, there are
+        no stray references to the original class.
         """
 
         @attr.s(slots=True)

tests/test_slots.py

@@ -3,6 +3,7 @@
 """
 Unit tests for slots-related functionality.
 """
+
 import functools
 import pickle
 import weakref
@@ -14,7 +15,7 @@
 import attr
 import attrs
 
-from attr._compat import PY_3_8_PLUS, PYPY
+from attr._compat import PY_3_8_PLUS, PY_3_14_PLUS, PYPY
 
 
 # Pympler doesn't work on PyPy.
@@ -774,6 +775,9 @@ def f(self) -> int:
 
 
 @pytest.mark.skipif(not PY_3_8_PLUS, reason="cached_property is 3.8+")
+@pytest.mark.xfail(
+    PY_3_14_PLUS, reason="3.14 returns weird annotation for cached_properies"
+)
 def test_slots_cached_property_infers_type():
     """
     Infers type of cached property.