KeyBuilder: support ABC, ABCMeta (#194)

pytools/persistent_dict.py

@@ -304,6 +304,8 @@ def update_for_type(key_hash, key):
         key_hash.update(
             f"{key.__module__}.{key.__qualname__}.{key.__name__}".encode("utf-8"))
 
+    update_for_ABCMeta = update_for_type  # noqa: N815
+
     @staticmethod
     def update_for_int(key_hash, key):
         sz = 8
@@ -352,7 +354,7 @@ def update_for_frozenset(self, key_hash, key):
     update_for_FrozenOrderedSet = update_for_frozenset  # noqa: N815
 
     @staticmethod
-    def update_for_NoneType(key_hash, key):  # noqa
+    def update_for_NoneType(key_hash, key):  # noqa: N802
         del key
         key_hash.update(b"<None>")
 

pytools/test/test_persistent_dict.py

@@ -470,6 +470,36 @@ def test_frozenorderedset_hashing():
     assert keyb(FrozenOrderedSet([1, 2, 3])) == keyb(FrozenOrderedSet([3, 2, 1]))
 
 
+def test_ABC_hashing():  # noqa: N802
+    from abc import ABC, ABCMeta
+
+    keyb = KeyBuilder()
+
+    class MyABC(ABC):
+        pass
+
+    assert keyb(MyABC) != keyb(ABC)
+
+    with pytest.raises(TypeError):
+        keyb(MyABC())
+
+    with pytest.raises(TypeError):
+        keyb(ABC())
+
+    class MyABC2(MyABC):
+        def update_persistent_hash(self, key_hash, key_builder):
+            key_builder.rec(key_hash, 42)
+
+    assert keyb(MyABC2) != keyb(MyABC)
+    assert keyb(MyABC2())
+
+    class MyABC3(metaclass=ABCMeta):  # noqa: B024
+        def update_persistent_hash(self, key_hash, key_builder):
+            key_builder.rec(key_hash, 42)
+
+    assert keyb(MyABC3) != keyb(MyABC) != keyb(MyABC3())
+
+
 def test_class_hashing():
     keyb = KeyBuilder()