Support for any field in Protobuf.js

Question

I use Protobuf.jsfor Node and it seems that the field type Anyfrom proto3 is not yet supported .

The author of the module suggests manually defining Any, as shown below.

syntax = "proto3";
package google.protobuf;
message Any {
  string type_url = 1;
  bytes value = 2;
}

However, it is not very clear to me what I should do after this. I wrote a minimal script that successfully uses a workaround:

myservice.proto

syntax = "proto3";  

package myservice;

message Any {
  string type_url = 1;
  bytes value = 2;
}

message Request {
    string id = 1;
}

message SampleA {
    string fieldA = 1;
}

message SampleB {
    string fieldB = 1;
}

message Response {
    string id = 1;
    repeated Any samples = 2;
}

service MyService {
  rpc Get (Request) returns (Response);
}

samples.js

const ProtoBuf = require('protobufjs');
const builder = ProtoBuf.loadProtoFile('./myservice.proto');
const Any = builder.build('Any');
const SampleA = builder.build('SampleA');
const SampleB = builder.build('SampleB');
const Response = builder.build('Response');

const pack = (message, prefix) => {
  return new Any({
    type_url: path.join((prefix || ''), message.toString()),
    value: message.encode()
  });
};

const unpack = (message) => {
  const b = builder.build(message.type_url.split('.')[1]);
  return b.decode(message.value);
};

// Pack and create a response
const sampleA = new SampleA({fieldA: 'testa'});
const sampleB = new SampleA({fieldA: 'testa'});
const response = new Response({
  id: '1234',
  samples: [pack(sampleA), pack(sampleB)]
});


// Unpack
const samples = response.samples.map((sample) => {
    return unpack(sample);
});

This works, and I return what I expected. However, I have a few questions:

• Is there a better way to get the full name of the message for building type_url. I used .toString () in my code, but I looked at implementations of other languages, and the posts seem to have some kind of getter for the name.

• .encode .decode ?