[do not merge] Empty fields fix (based on v2.0.0b1)

betterproto/__init__.py

@@ -255,12 +255,13 @@ class Enum(int, enum.Enum):
     """Protocol buffers enumeration base class. Acts like `enum.IntEnum`."""
 
     @classmethod
-    def from_string(cls, name: str) -> int:
-        """Return the value which corresponds to the string name."""
+    def from_value(cls, value: Union[str, int]) -> int:
+        """Return the value which corresponds to the string value."""
         try:
-            return cls.__members__[name]
-        except KeyError as e:
-            raise ValueError(f"Unknown value {name} for enum {cls.__name__}") from e
+            value = int(value)
+            return cls(value)
+        except (KeyError, ValueError, TypeError) as e:
+            raise ValueError(f"Unknown value {value} for enum {cls.__name__}") from e
 
 
 def _pack_fmt(proto_type: str) -> str:
@@ -611,8 +612,16 @@ def __bytes__(self) -> bytes:
                     output += _serialize_single(meta.number, TYPE_BYTES, buf)
                 else:
                     for item in value:
-                        output += _serialize_single(
-                            meta.number, meta.proto_type, item, wraps=meta.wraps or ""
+                        output += (
+                            _serialize_single(
+                                meta.number,
+                                meta.proto_type,
+                                item,
+                                wraps=meta.wraps or "",
+                            )
+                            # if it's an empty message it still needs to be represented
+                            # as an item in the repeated list
+                            or b"\n\x00"
                         )
             elif isinstance(value, dict):
                 for k, v in value.items():
@@ -636,8 +645,12 @@ def __bytes__(self) -> bytes:
 
     @classmethod
     def _type_hint(cls, field_name: str) -> Type:
-        module = inspect.getmodule(cls)
-        type_hints = get_type_hints(cls, vars(module))
+        global_vars = {}
+        for base in inspect.getmro(cls):
+            module = inspect.getmodule(base)
+            global_vars.update(vars(module))
+
+        type_hints = get_type_hints(cls, global_vars)
         return type_hints[field_name]
 
     @classmethod
@@ -831,9 +844,9 @@ def to_dict(
                         self._betterproto.cls_by_field[field_name]
                     )  # type: ignore
                     if isinstance(v, list):
-                        output[cased_name] = [enum_values[e].name for e in v]
+                        output[cased_name] = [enum_values[e].value for e in v]
                     else:
-                        output[cased_name] = enum_values[v].name
+                        output[cased_name] = enum_values[v].value
                 else:
                     output[cased_name] = v
         return output
@@ -888,9 +901,9 @@ def from_dict(self: T, value: dict) -> T:
                     elif meta.proto_type == TYPE_ENUM:
                         enum_cls = self._betterproto.cls_by_field[field_name]
                         if isinstance(v, list):
-                            v = [enum_cls.from_string(e) for e in v]
-                        elif isinstance(v, str):
-                            v = enum_cls.from_string(v)
+                            v = [enum_cls.from_value(e) for e in v]
+                        else:
+                            v = enum_cls.from_value(v)
 
                     if v is not None:
                         setattr(self, field_name, v)