add serialized descriptorproto to python classes

Author: MichaelSchuldes

src/betterproto2_compiler/plugin/models.py

@@ -266,6 +266,10 @@ def custom_methods(self) -> list[str]:
 
         return methods_source
 
+    @property
+    def descriptor(self):
+        return self.proto_obj.SerializeToString()
+
 
 def is_map(proto_field_obj: FieldDescriptorProto, parent_message: DescriptorProto) -> bool:
     """True if proto_field_obj is a map, otherwise False."""
@@ -594,6 +598,10 @@ def py_name(self) -> str:
     def deprecated(self) -> bool:
         return bool(self.proto_obj.options and self.proto_obj.options.deprecated)
 
+    @property
+    def descriptor(self):
+        return self.proto_obj.SerializeToString()
+
 
 @dataclass(kw_only=True)
 class ServiceCompiler(ProtoContentBase):

src/betterproto2_compiler/templates/template.py.j2

@@ -6,6 +6,10 @@ class {{ enum.py_name | add_to_all }}(betterproto2.Enum):
     """
     {% endif %}
 
+    @staticmethod
+    def _serialized_pb():
+        return {{ enum.descriptor }} 
+
     {% for entry in enum.entries %}
     {{ entry.name }} = {{ entry.value }}
     {% if entry.comment %}
@@ -45,6 +49,10 @@ class {{ message.py_name | add_to_all }}(betterproto2.Message):
     """
     {% endif %}
 
+    @staticmethod
+    def _serialized_pb():
+        return {{ message.descriptor }} 
+    
     {% for field in message.fields %}
     {{ field.get_field_string() }}
     {% if field.comment %}