Add option to print enums as ints in Ruby JSON encoder

[spiffyy99]

Fixes #6178

Adds the option to print enums as int values instead of the default strings for Ruby (similar to the option present for C++).

Example:

test.proto

enum TestEnum {
  Default = 0;
  Foo = 1;
}
enum TestMessage {
  TestEnum test_enum = 1;
}

code.rb

mymessage = TestMessage.new(:test_enum => 1)
puts TestMessage.encode(mymessage, {always_show_enums_as_ints: true})

will output:

{"testEnum":1}

[TeBoring]

Please send changes of upb to https://github.com/protocolbuffers/upb first.

[TeBoring]

Any update?

[spiffyy99]

@TeBoring yes, it seems like this repo (the ruby sections) have deprecated interfaces compared to the upb repo, mentioned here, doesn't seem like the changes here can be added to the upb repo (correct me if i'm wrong).

[TeBoring]

There is some ongoing work to update upb in ruby: #5866

Please send change to upb first. Once you are done, we probably have updated the upb in ruby.

[TeBoring]

We have update upb in ruby. Could you try again?

[acozzette]

@spiffyyeng I'm going to close this since there has been no activity in a long time, but feel free to comment here if you would still like to pursue this change.

[danielmorrison]

I'd personally love to see it, but don't know the internals enough yet to attempt it myself.

[haberman]

This would be an easy change.

We already support two options to the JSON encoder:

protobuf/ruby/ext/google/protobuf_c/message.c

Lines 1146 to 1155 in 7309e88

	if (RTEST(rb_hash_lookup2(hash_args,
	ID2SYM(rb_intern("preserve_proto_fieldnames")),
	Qfalse))) {
	options |= upb_JsonEncode_UseProtoNames;
	}
	if (RTEST(rb_hash_lookup2(hash_args, ID2SYM(rb_intern("emit_defaults")),
	Qfalse))) {
	options |= upb_JsonEncode_EmitDefaults;
	}

We would just need to add support for the upb_JsonEncode_FormatEnumsAsIntegers option: https://github.com/protocolbuffers/upb/blob/ada907989e075658b72a6dcb3ec8335b43596cbc/upb/json_encode.h#L48-L49

[MQuy]

hi @haberman, I created a pull request based on your suggestion. Would love to have your feedback #11673