Maps in proto2 files

[eiennohito]

It seems to be possible according to the docs (https://developers.google.com/protocol-buffers/docs/proto?hl=en#oneof), however codegen generated invalid messages.

for simple message like

syntax = "proto2";

message MapTest {
  map<string, int32> map1 = 1;
  map<string, float> map2 = 2;
}

it generates map entries like case class (key: Option[String], value: Option[Int]), but the type of map is Map[String, Int]. I believe that options are not needed here.

[thesamet]

If you switch to syntax="proto3" it will work as you expect. For syntax="proto2" it needs to be this way for backward compatibility.

[eiennohito]

For proto3 I believe that #40 still holds and there should be a mean for not wrapping fields in options.