Fix scalapb-validate setup instructions by bumping sbt-protoc (#1264)

* move scalapb-validation sbt instructions to scripted

* bump sbt-protoc for better integration with common-protos

Fixes scripted 10-scalapb-validate, see
* scalapb/ScalaPB#873 (comment)
* scalapb/scalapb-validate#70

Other changes
* cacheClassLoaders is now deprecated, see
  thesamet/sbt-protoc@2a730a4
* Forcing recompilation is no longer necessary as the cache gets
  invalidated if a sandbox genererator classpath is updated, see
  thesamet/sbt-protoc@80824b0
* The new classloader caching implementation resolves sandboxed
  generators artifacts earlier, even if they are no sources. That is
  the case for Test / protocGenerate, which was starting before
  codeGenProject / Compile / publishLocal, causing:
  > Error downloading com.lightbend.akka.grpc:akka-grpc-codegen_2.12:
  > 1.1.0-5-c5975cd5

* demonstrate usage of validate_at_construction

Requires scalapb/scalapb-validate@8529a55

benchmark-java/build.sbt

@@ -29,7 +29,7 @@ val root = project.in(file("."))
       "org.scalatest" %% "scalatest" % "3.1.2" % "test",
       "org.scalatestplus" %% "junit-4-12" % "3.1.2.0" % "test"
     ),
-    Compile / PB.generate := ((Compile / PB.generate) dependsOn (
+    PB.artifactResolver := (PB.artifactResolver dependsOn (
         codeGenProject / Compile / publishLocal)).value
   )
 

docs/src/main/paradox/apidesign.md

@@ -51,15 +51,7 @@ Follow the [documentation](https://scalapb.github.io/docs/validation) to update
 in order to generate the validators using `sbt-protoc` (@ref[used by Akka gRPC](buildtools/sbt.md#sbt-protoc-settings)).
 
 With the default parameters and target set by Akka gRPC, additions to your `build.sbt` should be:
-```scala
-import scalapb.GeneratorOption._
-
-libraryDependencies +=
-  "com.thesamet.scalapb" %% "scalapb-validate-core" % scalapb.validate.compiler.BuildInfo.version % "protobuf"
-
-Compile / PB.targets +=
-  scalapb.validate.gen(FlatPackage) -> (Compile / akkaGrpcCodeGeneratorSettings / target).value
-```
+@@snip[build.sbt](/sbt-plugin/src/sbt-test/gen-scala-server/10-scalapb-validate/build.sbt) { #setup }
 
 The `validate_at_construction` option can be particularly interesting in a server-side context
 since method implementations will automatically receive pre-validated requests and will not

project/ReflectiveCodeGen.scala

@@ -64,8 +64,6 @@ object ReflectiveCodeGen extends AutoPlugin {
             }
           }
         }.value,
-        // Reload generators on each invocation
-        PB.cacheClassLoaders := false,
         setCodeGenerator := loadAndSetGenerator(
           // the magic sauce: use the output classpath from the the sbt-plugin project and instantiate generators from there
           (fullClasspath in Compile in ProjectRef(file("."), "sbt-akka-grpc")).value,
@@ -76,7 +74,6 @@ object ReflectiveCodeGen extends AutoPlugin {
           codeGeneratorSettings.value,
           PB.targets.value.asInstanceOf[ListBuffer[Target]],
           scalaBinaryVersion.value),
-        PB.recompile ~= (_ => true),
         PB.protoSources in Compile := PB.protoSources.value ++ Seq(
           PB.externalIncludePath.value,
           sourceDirectory.value / "proto"))) ++ Seq(

project/plugins.sbt

@@ -1,6 +1,6 @@
 enablePlugins(BuildInfoPlugin)
 
-val sbtProtocV = "1.0.0"
+val sbtProtocV = "1.0.1"
 
 buildInfoKeys := Seq[BuildInfoKey]("sbtProtocVersion" -> sbtProtocV)
 

sbt-plugin/src/sbt-test/gen-scala-server/10-scalapb-validate/build.sbt

@@ -0,0 +1,13 @@
+resolvers += Resolver.sonatypeRepo("staging")
+resolvers += Resolver.bintrayRepo("akka", "snapshots")
+
+//#setup
+import scalapb.GeneratorOption._
+
+enablePlugins(AkkaGrpcPlugin)
+
+libraryDependencies +=
+  "com.thesamet.scalapb" %% "scalapb-validate-core" % scalapb.validate.compiler.BuildInfo.version % "protobuf"
+Compile / PB.targets +=
+  scalapb.validate.gen(FlatPackage) -> (Compile / akkaGrpcCodeGeneratorSettings / target).value
+//#setup

sbt-plugin/src/sbt-test/gen-scala-server/10-scalapb-validate/project/plugins.sbt

@@ -0,0 +1,3 @@
+addSbtPlugin("com.lightbend.akka.grpc" % "sbt-akka-grpc" % sys.props("project.version"))
+
+libraryDependencies ++= Seq("com.thesamet.scalapb" %% "scalapb-validate-codegen" % "0.2.2")

sbt-plugin/src/sbt-test/gen-scala-server/10-scalapb-validate/src/main/protobuf/helloworld.proto

@@ -0,0 +1,39 @@
+syntax = "proto3";
+
+option java_package = "example.myapp.helloworld.grpc";
+
+package helloworld;
+
+import "validate/validate.proto";
+import "scalapb/scalapb.proto";
+import "scalapb/validate.proto";
+
+option (scalapb.options) = {
+    scope: FILE
+    [scalapb.validate.file] {
+        validate_at_construction: true
+        insert_validator_instance: false
+    }
+};
+
+// 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 [(validate.rules).string.min_len = 3];;
+}
+
+// The response message containing the greetings
+message HelloReply {
+    string message = 1;
+}

sbt-plugin/src/sbt-test/gen-scala-server/10-scalapb-validate/src/main/scala/example/myapp/Main.scala

@@ -0,0 +1,20 @@
+package example.myapp
+
+import scala.util.{Failure, Success, Try}
+import scalapb.validate._
+
+import example.myapp.helloworld.grpc.HelloRequest
+
+object Main extends App {
+
+  Try(HelloRequest("valid")) match {
+    case Success(_) => // expected
+    case Failure(e) => throw new RuntimeException("unexpected violations for \"valid\"", e)
+  }
+
+  Try(HelloRequest("ko")) match {
+    case Success(_) => throw new RuntimeException("unexpected success for \"ko\"")
+    case Failure(e) => // expected
+  }
+
+}

sbt-plugin/src/sbt-test/gen-scala-server/10-scalapb-validate/src/main/scala/example/myapp/helloworld/GreeterServiceImpl.scala

@@ -0,0 +1,19 @@
+package example.myapp.helloworld
+
+import scala.concurrent.Future
+
+import akka.NotUsed
+import akka.stream.scaladsl.Source
+
+import example.myapp.helloworld.grpc._
+
+class GreeterServiceImpl extends GreeterService {
+  override def sayHello(in: HelloRequest): Future[HelloReply] = ???
+
+  override def streamHellos(in: Source[HelloRequest, NotUsed]): Source[HelloReply, NotUsed] = ???
+
+  override def itKeepsTalking(in: Source[HelloRequest, NotUsed]): Future[HelloReply] = ???
+
+  override def itKeepsReplying(in: HelloRequest): Source[HelloReply, NotUsed] = ???
+
+}

sbt-plugin/src/sbt-test/gen-scala-server/10-scalapb-validate/test

@@ -0,0 +1 @@
+> run