test also non-repeated native plugin

src/sbt-test/settings/native/build.sbt

@@ -1,4 +1,6 @@
 Compile / PB.targets := Seq(
+  PB.gens.java                -> (Compile / sourceManaged).value,
+  PB.gens.plugin("grpc-java") -> (Compile / sourceManaged).value,
   (
     PB.gens.plugin("scala"),
     Seq()
@@ -13,6 +15,11 @@ val scalapbcClassifier =
   if (protocbridge.SystemDetector.detectedClassifier().startsWith("windows")) "windows"
   else "unix"
 
+libraryDependencies += "javax.annotation" % "javax.annotation-api" % "1.3.2"
+libraryDependencies += "io.grpc"          % "grpc-stub"            % "1.35.0"
+libraryDependencies += "io.grpc"          % "grpc-protobuf"        % "1.35.0"
+libraryDependencies += "io.grpc"          % "protoc-gen-grpc-java" % "1.35.0" asProtocPlugin ()
+
 libraryDependencies += "com.thesamet.scalapb" %% "scalapb-runtime"  % "0.10.10"
 libraryDependencies += "com.thesamet.scalapb"  % "protoc-gen-scala" % "0.10.10" % "protobuf" artifacts (
   Artifact(

src/sbt-test/settings/native/src/main/protobuf/helloworld.proto

@@ -0,0 +1,27 @@
+syntax = "proto3";
+
+option java_package = "example.myapp.helloworld.grpc";
+
+package helloworld;
+
+// The greeting service definition.
+service GreeterService {
+    // Sends a greeting
+    rpc SayHello (HelloRequest) returns (HelloReply) {}
+
+    rpc ItKeepsTalking (stream HelloRequest) returns (HelloReply) {}
+
+    rpc ItKeepsReplying (HelloRequest) returns (stream HelloReply) {}
+
+    rpc StreamHellos (stream HelloRequest) returns (stream HelloReply) {}
+}
+
+// The request message containing the user's name.
+message HelloRequest {
+    string name = 1;
+}
+
+// The response message containing the greetings
+message HelloReply {
+    string message = 1;
+}

src/sbt-test/settings/native/test

@@ -1,5 +1,8 @@
 > compile
 
+$ exists target/scala-2.12/src_managed/main/example/myapp/helloworld/grpc/Helloworld.java
+$ exists target/scala-2.12/src_managed/main/example/myapp/helloworld/grpc/GreeterServiceGrpc.java
+
 $ exists target/scala-2.12/src_managed/main/test/test1/Test1Proto.scala
 $ exists target/scala-2.12/src_managed/main/test/test1/msg.scala
 $ exists target/scala-2.12/src_managed/main/test/Test1Proto.scala