add equality and membership tests to Optional

CHANGELOG.md

 # v2.15.6
+
+* added equality checking and membership test to Optional

satella/__init__.py

-__version__ = '2.15.6a1'
+__version__ = '2.15.6'

satella/coding/optionals.py

@@ -54,12 +54,32 @@ class Optional(Proxy):
     * getattr
     * getitem/setitem/delitem
     * testing for truth
+    * comparison (with nonexistent elements always comparing false)
+    * membership test (with nonexistent elements always returning false)
+
+    .. warning:: Returned objects via getattr and getitem are NOT wrapped in an
+        Optional. You need to do it by hand or just file an issue. I'll add that when I
+        need it.
+
+    :param obj: object to wrap
     """
     __slots__ = ()
 
     def __init__(self, obj):
         super().__init__(obj)
 
+    def __contains__(self, item) -> bool:
+        me = getattr(self, '_Proxy__obj')
+        if me is None:
+            return False
+        return item in me
+
+    def __eq__(self, other) -> bool:
+        me = getattr(self, '_Proxy__obj')
+        if me is None:
+            return False
+        return me == other
+
     def __getattr__(self, item):
         if getattr(self, '_Proxy__obj') is None:
             return EMPTY_OPTIONAL

tests/test_coding/test_optionals.py

@@ -15,6 +15,17 @@ class TestOptionals(unittest.TestCase):
         self.assertFalse(c)
         self.assertTrue(b)
 
+    def test_optional_eq(self):
+        class Opt:
+            a = 5
+            b = [2]
+
+        a = Opt()
+        self.assertEqual(Optional(a).a, 5)
+        self.assertIn(2, Optional(a).b)
+        self.assertNotEqual(Optional(None).a, 5)
+        self.assertNotIn(2, Optional(None).b)
+
     def test_optional(self):
         self.assertIsNone(call_if_nnone(None))
         b = call_if_nnone(lambda y: y, 5)