message Empty is defined twice in interop-testing sub-project

Message Empty is once defined in the interop-testing sub-project itself:

https://github.com/grpc/grpc-java/blob/95917b8f280115bdb946e455151034a2650f48a6/interop-testing/src/main/proto/io/grpc/testing/integration/empty.proto#L22-L30

And then again pulled in from protobuf-java

https://github.com/google/protobuf/blob/d6a17aadeb6fc306d3d8c3b5c07edc41f6bc551e/src/google/protobuf/empty.proto#L43-L52

via the dependency chain: grpc-interop-testing -> grpc-protobuf -> protobuf-java-util -> protobuf-java

This becomes a problem when generating grpc classes using ScalaPB as it tries to place both under the same package and the same name.

I would expect interop-testing to not define Empty message and use the one from protobuf-java instead. Would that be possible to change?

[ejona86]

The empty.proto is broken:

package grpc.testing;

option java_package = "com.google.protobuf";

It’s in the correct protobuf package, but the java package is wrong. It should be in io.grpc.testing.integration.

[jyane]

@ejona86

Normally we should always make changes to the “canonical” version first, which would eventually in grpc/grpc-proto. For now, most of the “canonical” versions are in grpc/grpc. But as we can see we’ve already diverged here.

Using grpc/grpc-proto is quite reasonable for me. It means eventually the chance of resolving #4097.

It would be good to send a PR to grpc/grpc as well to add the java_package option

I’ll do once my PR was merged if you want to.