Ruby JSON: always accept both camelCase and original field names.

For JSON encoding we provide a new option to decide at
encode time whether to use camelCase or original proto field
names:

  json = MapMessage.encode_json(m, :preserve_proto_fieldnames => true)

1 files changed, 36 insertions, 9 deletions

diff --git a/ruby/ext/google/protobuf_c/encode_decode.c b/ruby/ext/google/protobuf_c/encode_decode.c
index c2c369eb..9bc7273e 100644
--- a/ruby/ext/google/protobuf_c/encode_decode.c
+++ b/ruby/ext/google/protobuf_c/encode_decode.c
@@ -1130,13 +1130,23 @@ static const upb_handlers* msgdef_pb_serialize_handlers(Descriptor* desc) {
   return desc->pb_serialize_handlers;
 }
 
-static const upb_handlers* msgdef_json_serialize_handlers(Descriptor* desc) {
-  if (desc->json_serialize_handlers == NULL) {
-    desc->json_serialize_handlers =
-        upb_json_printer_newhandlers(
-            desc->msgdef, &desc->json_serialize_handlers);
+static const upb_handlers* msgdef_json_serialize_handlers(
+    Descriptor* desc, bool preserve_proto_fieldnames) {
+  if (preserve_proto_fieldnames) {
+    if (desc->json_serialize_handlers == NULL) {
+      desc->json_serialize_handlers =
+          upb_json_printer_newhandlers(
+              desc->msgdef, true, &desc->json_serialize_handlers);
+    }
+    return desc->json_serialize_handlers;
+  } else {
+    if (desc->json_serialize_handlers_preserve == NULL) {
+      desc->json_serialize_handlers_preserve =
+          upb_json_printer_newhandlers(
+              desc->msgdef, false, &desc->json_serialize_handlers_preserve);
+    }
+    return desc->json_serialize_handlers_preserve;
   }
-  return desc->json_serialize_handlers;
 }
 
 /*
@@ -1181,16 +1191,33 @@ VALUE Message_encode(VALUE klass, VALUE msg_rb) {
  *
  * Encodes the given message object into its serialized JSON representation.
  */
-VALUE Message_encode_json(VALUE klass, VALUE msg_rb) {
+VALUE Message_encode_json(int argc, VALUE* argv, VALUE klass) {
   VALUE descriptor = rb_ivar_get(klass, descriptor_instancevar_interned);
   Descriptor* desc = ruby_to_Descriptor(descriptor);
-
+  VALUE msg_rb;
+  VALUE preserve_proto_fieldnames = Qfalse;
   stringsink sink;
+
+  if (argc < 1 || argc > 2) {
+    rb_raise(rb_eArgError, "Expected 1 or 2 arguments.");
+  }
+
+  msg_rb = argv[0];
+
+  if (argc == 2) {
+    VALUE hash_args = argv[1];
+    if (TYPE(hash_args) != T_HASH) {
+      rb_raise(rb_eArgError, "Expected hash arguments.");
+    }
+    preserve_proto_fieldnames = rb_hash_lookup2(
+        hash_args, ID2SYM(rb_intern("preserve_proto_fieldnames")), Qfalse);
+  }
+
   stringsink_init(&sink);
 
   {
     const upb_handlers* serialize_handlers =
-        msgdef_json_serialize_handlers(desc);
+        msgdef_json_serialize_handlers(desc, RTEST(preserve_proto_fieldnames));
     upb_json_printer* printer;
     stackenv se;
     VALUE ret;