fix: Corrected enum metaclass to fix pickle.dumps() (#1495)

* Corrected enum metaclass to fix pickle.dumps()

* considered case with colliding class names (try to distinguish by file name)

* reverted simple solution back (without attempt to support duplicate Enum class names)

---------

Co-authored-by: sgrekov <sgrekov@lohika.com>
Co-authored-by: Erik Wrede <erikwrede@users.noreply.github.com>

graphene/tests/issues/test_881.py

@@ -0,0 +1,27 @@
+import pickle
+
+from ...types.enum import Enum
+
+
+class PickleEnum(Enum):
+    # is defined outside of test because pickle unable to dump class inside ot pytest function
+    A = "a"
+    B = 1
+
+
+def test_enums_pickling():
+    a = PickleEnum.A
+    pickled = pickle.dumps(a)
+    restored = pickle.loads(pickled)
+    assert type(a) is type(restored)
+    assert a == restored
+    assert a.value == restored.value
+    assert a.name == restored.name
+
+    b = PickleEnum.B
+    pickled = pickle.dumps(b)
+    restored = pickle.loads(pickled)
+    assert type(a) is type(restored)
+    assert b == restored
+    assert b.value == restored.value
+    assert b.name == restored.name

graphene/types/enum.py

@@ -31,9 +31,11 @@ class EnumMeta(SubclassWithMeta_Meta):
         # with the enum values.
         enum_members.pop("Meta", None)
         enum = PyEnum(cls.__name__, enum_members)
-        return SubclassWithMeta_Meta.__new__(
+        obj = SubclassWithMeta_Meta.__new__(
             cls, name_, bases, dict(classdict, __enum__=enum), **options
         )
+        globals()[name_] = obj.__enum__
+        return obj
 
     def get(cls, value):
         return cls._meta.enum(value)