feat: added ParseFromString method to message for compatibility with official protobuf method

Author: simon-saliba

src/betterproto/__init__.py

@@ -1022,6 +1022,29 @@ def FromString(cls: Type[T], data: bytes) -> T:
         """
         return cls().parse(data)
 
+    # For compatibility with Google protobuf official implementation.
+    def ParseFromString(self, data: bytes) -> T:
+        """
+        Parse the binary encoded Protobuf into this message instance. This
+        returns the instance itself and is therefore assignable and chainable.
+
+        .. note::
+            This is a method for compatibility with other libraries,
+            you should really use :meth:`parse`.
+
+
+        Parameters
+        -----------
+        data: :class:`bytes`
+            The data to parse the protobuf from.
+
+        Returns
+        --------
+        :class:`Message`
+            The initialized message.
+        """
+        return self.parse(data)
+
     def to_dict(
         self, casing: Casing = Casing.CAMEL, include_default_values: bool = False
     ) -> Dict[str, Any]:

tests/test_features.py

@@ -485,3 +485,13 @@ def test_service_argument__expected_parameter():
     do_thing_request_parameter = sig.parameters["do_thing_request"]
     assert do_thing_request_parameter.default is Parameter.empty
     assert do_thing_request_parameter.annotation == "DoThingRequest"
+
+
+def test_message_parse_from_string():
+    @dataclass
+    class SimpleMessage(betterproto.Message):
+        message: str = betterproto.string_field(1)
+
+    test_message = SimpleMessage(message="test message")
+
+    assert test_message == test_message.ParseFromString(bytes(test_message))