Nextgen Proto Pythonic API: “Add-on” proto for JSON serialize/parse

- add google.protobuf.proto_json module
- wrap json_format's MessageToDict/ParseDict to the new module:

def serialize(
    message: Message,
    always_print_fields_with_no_presence: bool=False,
    preserving_proto_field_name: bool=False,
    use_integers_for_enums: bool=False,
    descriptor_pool: Optional[DescriptorPool]=None,
    float_precision: int=None,
) -> dict

def parse(
    message_class: Type[Message],
    js_dict: dict,
    ignore_unknown_fields: bool=False,
    descriptor_pool: Optional[DescriptorPool]=None,
    max_recursion_depth: int=100
) -> Message

PiperOrigin-RevId: 634490919

python/build_targets.bzl

@@ -421,6 +421,11 @@ def build_targets(name):
         srcs = ["google/protobuf/internal/proto_test.py"],
     )
 
+    internal_py_test(
+        name = "proto_json_test",
+        srcs = ["google/protobuf/internal/proto_json_test.py"],
+    )
+
     native.cc_library(
         name = "proto_api",
         hdrs = ["google/protobuf/proto_api.h"],

python/google/protobuf/internal/proto_json_test.py

@@ -0,0 +1,33 @@
+# -*- coding: utf-8 -*-
+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Tests Nextgen Pythonic protobuf APIs."""
+
+import unittest
+
+from google.protobuf import proto_json
+from google.protobuf.util import json_format_proto3_pb2
+
+
+class ProtoJsonTest(unittest.TestCase):
+
+  def testSimpleSerialize(self):
+    message = json_format_proto3_pb2.TestMessage()
+    message.int32_value = 12345
+    expected = {'int32Value': 12345}
+    self.assertEqual(expected, proto_json.serialize(message))
+
+  def testSimpleParse(self):
+    expected = 12345
+    js_dict = {'int32Value': expected}
+    message = proto_json.parse(json_format_proto3_pb2.TestMessage,
+                               js_dict)
+    self.assertEqual(expected, message.int32_value)
+
+if __name__ == "__main__":
+  unittest.main()

python/google/protobuf/proto_json.py

@@ -0,0 +1,83 @@
+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+#
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Contains the Nextgen Pythonic Protobuf JSON APIs."""
+
+from typing import Optional, Type
+
+from google.protobuf.message import Message
+from google.protobuf.descriptor_pool import DescriptorPool
+from google.protobuf import json_format
+
+def serialize(
+    message: Message,
+    always_print_fields_with_no_presence: bool=False,
+    preserving_proto_field_name: bool=False,
+    use_integers_for_enums: bool=False,
+    descriptor_pool: Optional[DescriptorPool]=None,
+    float_precision: int=None,
+) -> dict:
+  """Converts protobuf message to a dictionary.
+
+  When the dictionary is encoded to JSON, it conforms to proto3 JSON spec.
+
+  Args:
+    message: The protocol buffers message instance to serialize.
+    always_print_fields_with_no_presence: If True, fields without
+      presence (implicit presence scalars, repeated fields, and map fields) will
+      always be serialized. Any field that supports presence is not affected by
+      this option (including singular message fields and oneof fields).
+    preserving_proto_field_name: If True, use the original proto field names as
+      defined in the .proto file. If False, convert the field names to
+      lowerCamelCase.
+    use_integers_for_enums: If true, print integers instead of enum names.
+    descriptor_pool: A Descriptor Pool for resolving types. If None use the
+      default.
+    float_precision: If set, use this to specify float field valid digits.
+
+  Returns:
+    A dict representation of the protocol buffer message.
+  """
+  return json_format.MessageToDict(
+      message,
+      always_print_fields_with_no_presence=always_print_fields_with_no_presence,
+      preserving_proto_field_name=preserving_proto_field_name,
+      use_integers_for_enums=use_integers_for_enums,
+      float_precision=float_precision,
+  )
+
+def parse(
+    message_class: Type[Message],
+    js_dict: dict,
+    ignore_unknown_fields: bool=False,
+    descriptor_pool: Optional[DescriptorPool]=None,
+    max_recursion_depth: int=100
+) -> Message:
+  """Parses a JSON dictionary representation into a message.
+
+  Args:
+    message_class: The message meta class.
+    js_dict: Dict representation of a JSON message.
+    ignore_unknown_fields: If True, do not raise errors for unknown fields.
+    descriptor_pool: A Descriptor Pool for resolving types. If None use the
+      default.
+    max_recursion_depth: max recursion depth of JSON message to be deserialized.
+      JSON messages over this depth will fail to be deserialized. Default value
+      is 100.
+
+  Returns:
+    A new message passed from json_dict.
+  """
+  new_message = message_class()
+  json_format.ParseDict(
+      js_dict=js_dict,
+      message=new_message,
+      ignore_unknown_fields=ignore_unknown_fields,
+      descriptor_pool=descriptor_pool,
+      max_recursion_depth=max_recursion_depth,
+  )
+  return new_message