Implement Message.__bool__

src/betterproto/__init__.py

@@ -551,6 +551,12 @@ def __setattr__(self, attr: str, value: Any) -> None:
 
         super().__setattr__(attr, value)
 
+    def __bool__(self) -> bool:
+        return any(
+            getattr(self, field_name)
+            for field_name in self._betterproto.meta_by_field_name
+        )
+
     @property
     def _betterproto(self):
         """