tests/basics/class_setname_hazard: Document __set_name__ hazard.

AJMansfield · AJMansfield · commit b6b4c35b246b · 2025-02-24T16:07:04.000-05:00
Signed-off-by: Anson Mansfield &lt;amansfield@mantaro.com&gt;
diff --git a/tests/basics/class_setname_hazard.py b/tests/basics/class_setname_hazard.py
@@ -0,0 +1,118 @@
+def skip_if_no_descriptors():
+    class Descriptor:
+        def __get__(self, obj, cls):
+            return
+
+    class TestClass:
+        Forward = Descriptor()
+
+    a = TestClass()
+    try:
+        a.__class__
+    except AttributeError:
+        # Target doesn't support __class__.
+        print("SKIP")
+        raise SystemExit
+
+    b = a.Forward
+    if "Descriptor" in repr(b.__class__):
+        # Target doesn't support descriptors.
+        print("SKIP")
+        raise SystemExit
+
+
+skip_if_no_descriptors()
+
+
+# Test basic hazard-free mutations of the enclosing class.
+# See also cpydiff/core_class_setname_hazard.py for broken non-hazard-free cases.
+
+
+class GetSibling:
+    def __set_name__(self, owner, name):
+        print(getattr(owner, name + "_sib"))
+
+
+class GetSiblingTest:
+    desc = GetSibling()
+    desc_sib = 101
+
+
+t101 = GetSiblingTest()
+
+
+class SetSibling:
+    def __set_name__(self, owner, name):
+        setattr(owner, name + "_sib", 102)
+
+
+class SetSiblingTest:
+    desc = SetSibling()
+
+
+t102 = SetSiblingTest()
+
+print(t102.desc_sib)
+
+
+class DelSibling:
+    def __set_name__(self, owner, name):
+        delattr(owner, name + "_sib")
+
+
+class DelSiblingTest:
+    desc = DelSibling()
+    desc_sib = 103
+
+
+t103 = DelSiblingTest()
+
+try:
+    print(t103.desc_sib)
+except AttributeError:
+    print("AttributeError")
+
+
+class GetSelf:
+    x = 201
+
+    def __set_name__(self, owner, name):
+        print(getattr(owner, name).x)
+
+
+class GetSelfTest:
+    desc = GetSelf()
+
+
+t201 = GetSelfTest()
+
+
+class SetSelf:
+    def __set_name__(self, owner, name):
+        setattr(owner, name, 202)
+
+
+class SetSelfTest:
+    desc = SetSelf()
+
+
+t202 = SetSelfTest()
+
+print(t202.desc)
+
+
+class DelSelf:
+    def __set_name__(self, owner, name):
+        delattr(owner, name)
+
+
+class DelSelfTest:
+    desc = DelSelf()
+
+
+t203 = DelSelfTest()
+
+try:
+    print(t203.desc)
+except AttributeError:
+    print("AttributeError")
