Re-added ability to call len on serializers

hydras/base.py

@@ -110,6 +110,9 @@ def is_constant_size(cls) -> bool:
     def byte_size(cls) -> int:
         return cls.__hydras_metadata__.size
 
+    def __len__(self):
+        return self.byte_size
+
     @property
     def __hydras_metadata__(cls) -> SerializerMetadata:
         return getattr(cls, cls.METAATTR)
@@ -130,6 +133,9 @@ def byte_size(self) -> int:
     def __hydras_metadata__(self) -> SerializerMetadata:
         return type(self).__hydras_metadata__
 
+    def __len__(self):
+        return self.byte_size
+
     def __init__(self, default_value, validator: Callable[[Any], bool] = None):
         """
         Creates a new formatter.

setup.py

@@ -5,7 +5,7 @@
     long_description = f.read()
 
 setup(name='Hydras',
-      version='3.0.8',
+      version='3.0.9',
       description='A module for constructions of structured binary packets.',
       author='Gilad Naaman',
       author_email='gilad@naaman.io',

tests/test_struct.py

@@ -39,6 +39,14 @@ class ComplicatedStruct(Struct):
 class StructTests(HydrasTestCase):
     """ A testcase checking for a few of `Struct`'s features. """
 
+    def test_member_length(self):
+        self.assertEqual(len(SimpleStruct.b_first_variable), 1)
+        self.assertEqual(len(SimpleStruct.a_second_variable), 2)
+        self.assertEqual(len(SimpleStruct.x_third_variable), 1)
+
+        self.assertEqual(len(ComplicatedStruct.other_struct), 1)
+        self.assertEqual(len(ComplicatedStruct.some_field), 12)
+
     def test_serialize_simple(self):
         """ Test serialization of a simple struct. """
         obj = SimpleStruct()