feat: Add jsonPayload trait

modules/smithy-tests/src/test/scala/jsonrpclib/JsonPayloadValidatorSpec.scala

@@ -0,0 +1,99 @@
+package jsonrpclib
+
+import jsonrpclib.ModelUtils.assembleModel
+import jsonrpclib.ModelUtils.eventsWithoutLocations
+import software.amazon.smithy.model.shapes.ShapeId
+import software.amazon.smithy.model.validation.Severity
+import software.amazon.smithy.model.validation.ValidationEvent
+import weaver._
+
+object JsonPayloadValidatorSpec extends FunSuite {
+  test("no error when jsonPayload is used on the input, output or error structure's member") {
+
+    assembleModel(
+      """$version: "2"
+        |namespace test
+        |
+        |use jsonrpclib#jsonRPC
+        |use jsonrpclib#jsonRequest
+        |use jsonrpclib#jsonPayload
+        |
+        |@jsonRPC
+        |service MyService {
+        |  operations: [OpA]
+        |}
+        |
+        |@jsonRequest("foo")
+        |operation OpA {
+        |  input: OpInput
+        |  output: OpOutput
+        |  errors: [OpError]
+        |}
+        |
+        |structure OpInput {
+        |  @jsonPayload
+        |  data: String  
+        |}
+        |
+        |structure OpOutput {
+        |  @jsonPayload
+        |  data: String  
+        |}
+        |
+        |@error("client")
+        |structure OpError {
+        |  @jsonPayload
+        |  data: String  
+        |}
+        |
+        |""".stripMargin
+    ).unwrap()
+
+    success
+  }
+  test("return an error when jsonPayload is used in a nested structure") {
+    val events = eventsWithoutLocations(
+      assembleModel(
+        """$version: "2"
+        |namespace test
+        |
+        |use jsonrpclib#jsonRPC
+        |use jsonrpclib#jsonRequest
+        |use jsonrpclib#jsonPayload
+        |
+        |@jsonRPC
+        |service MyService {
+        |  operations: [OpA]
+        |}
+        |
+        |@jsonRequest("foo")
+        |operation OpA {
+        |  input: OpInput
+        |}
+        |
+        |structure OpInput {
+        |  data: NestedStructure  
+        |}
+        |
+        |structure NestedStructure {
+        |  @jsonPayload
+        |  data: String  
+        |}
+        |""".stripMargin
+      )
+    )
+
+    val expected = ValidationEvent
+      .builder()
+      .id("jsonPayload.OnlyTopLevel")
+      .shapeId(ShapeId.fromParts("test", "NestedStructure", "data"))
+      .severity(Severity.ERROR)
+      .message(
+        "Found an incompatible shape when validating the constraints of the `jsonrpclib#jsonPayload` trait attached to `test#NestedStructure$data`: jsonPayload can only be used on the top level of an operation input/output/error."
+      )
+      .build()
+
+    assert(events.contains(expected))
+  }
+
+}

modules/smithy/src/main/resources/META-INF/services/software.amazon.smithy.model.validation.Validator

@@ -1,3 +1,3 @@
 jsonrpclib.validation.JsonNotificationOutputValidator
 jsonrpclib.validation.UniqueJsonRpcMethodNamesValidator
-jsonrpclib.validation.JsonRpcOperationValidator
+jsonrpclib.validation.JsonRpcOperationValidator

modules/smithy/src/main/resources/META-INF/smithy/jsonrpclib.smithy

@@ -7,6 +7,7 @@ namespace jsonrpclib
 @protocolDefinition(traits: [
     jsonRequest
     jsonNotification
+    jsonPayload
     smithy.api#jsonName
     smithy.api#length
     smithy.api#pattern
@@ -31,3 +32,16 @@ string jsonRequest
 /// see https://www.jsonrpc.org/specification#notification
 @trait(selector: "operation", conflicts: [jsonRequest])
 string jsonNotification
+
+
+/// Binds a single structure member to the payload of a jsonrpc message.
+/// Just like @httpPayload, but for jsonRPC.
+@trait(selector: "structure > member", structurallyExclusive: "member")
+@traitValidators({
+    "jsonPayload.OnlyTopLevel": { 
+        message: "jsonPayload can only be used on the top level of an operation input/output/error.", 
+        severity: "ERROR", 
+        selector: "$allowedShapes(:root(operation -[input, output, error]-> structure > member)) :not(:in(${allowedShapes}))"
+    }
+})
+structure jsonPayload {}

modules/smithy4s-tests/src/main/smithy/spec.smithy

@@ -5,6 +5,7 @@ namespace test
 use jsonrpclib#jsonNotification
 use jsonrpclib#jsonRPC
 use jsonrpclib#jsonRequest
+use jsonrpclib#jsonPayload
 
 @jsonRPC
 service TestServer {
@@ -29,6 +30,36 @@ operation Greet {
     errors: [NotWelcomeError]
 }
 
+
+@jsonRPC
+service TestServerWithPayload {
+    operations: [GreetWithPayload]
+}
+
+@jsonRequest("greetWithPayload")
+operation GreetWithPayload {
+    input := {
+        @required
+        @jsonPayload
+        payload: GreetInputPayload
+    }
+    output := {
+        @required
+        @jsonPayload
+        payload: GreetOutputPayload
+    }
+}
+
+structure GreetInputPayload {
+    @required
+    name: String
+}
+
+structure GreetOutputPayload {
+    @required
+    message: String
+}
+
 @error("client")
 structure NotWelcomeError {
     @required

modules/smithy4s-tests/src/test/scala/jsonrpclib/smithy4sinterop/TestClientSpec.scala

@@ -7,10 +7,7 @@ import io.circe.Decoder
 import io.circe.Encoder
 import jsonrpclib._
 import jsonrpclib.fs2._
-import test.GreetInput
-import test.GreetOutput
-import test.PingInput
-import test.TestServer
+import test._
 import weaver._
 
 import scala.concurrent.duration._
@@ -66,4 +63,19 @@ object TestClientSpec extends SimpleIOSuite {
       expect.same(result, Some(PingInput("hello")))
     }
   }
+
+  testRes("Round trip with jsonPayload") {
+    implicit val greetInputDecoder: Decoder[GreetInput] = CirceJsonCodec.fromSchema
+    implicit val greetOutputEncoder: Encoder[GreetOutput] = CirceJsonCodec.fromSchema
+    val endpoint: Endpoint[IO] =
+      Endpoint[IO]("greetWithPayload").simple[GreetInput, GreetOutput](in => IO(GreetOutput(s"Hello ${in.name}")))
+
+    for {
+      clientSideChannel <- setup(endpoint)
+      clientStub = ClientStub(TestServerWithPayload, clientSideChannel)
+      result <- clientStub.greetWithPayload(GreetInputPayload("Bob")).toStream
+    } yield {
+      expect.same(result.payload.message, "Hello Bob")
+    }
+  }
 }

modules/smithy4s-tests/src/test/scala/jsonrpclib/smithy4sinterop/TestServerSpec.scala

@@ -12,17 +12,8 @@ import jsonrpclib.Monadic
 import jsonrpclib.Payload
 import smithy4s.kinds.FunctorAlgebra
 import smithy4s.Service
-import test.GetWeatherInput
-import test.GetWeatherOutput
-import test.GreetInput
-import test.GreetOutput
-import test.NotWelcomeError
-import test.PingInput
-import test.TestClient
-import test.TestServer
-import test.TestServerOperation
-import test.TestServerOperation.GreetError
-import test.WeatherService
+import test._
+import test.TestServerOperation._
 import weaver._
 
 import scala.concurrent.duration._
@@ -241,4 +232,22 @@ object TestServerSpec extends SimpleIOSuite {
       expect.same(getWeatherResult.weather, "sunny")
     }
   }
+
+  testRes("Round trip with jsonPayload") {
+    implicit val greetInputEncoder: Encoder[GreetInput] = CirceJsonCodec.fromSchema
+    implicit val greetOutputDecoder: Decoder[GreetOutput] = CirceJsonCodec.fromSchema
+
+    object ServerImpl extends TestServerWithPayload[IO] {
+      def greetWithPayload(payload: GreetInputPayload): IO[GreetWithPayloadOutput] =
+        IO.pure(GreetWithPayloadOutput(GreetOutputPayload(s"Hello ${payload.name}")))
+    }
+
+    for {
+      clientSideChannel <- setup(_ => AlgebraWrapper(ServerImpl))
+      remoteFunction = clientSideChannel.simpleStub[GreetInput, GreetOutput]("greetWithPayload")
+      result <- remoteFunction(GreetInput("Bob")).toStream
+    } yield {
+      expect.same(result.message, "Hello Bob")
+    }
+  }
 }

modules/smithy4s/src/main/scala/jsonrpclib/smithy4sinterop/ClientStub.scala

@@ -24,7 +24,7 @@ object ClientStub {
     * Supports both standard request-response and fire-and-forget notification endpoints.
     */
   def apply[Alg[_[_, _, _, _, _]], F[_]: Monadic](service: Service[Alg], channel: Channel[F]): service.Impl[F] =
-    new ClientStub(service, channel).compile
+    new ClientStub(JsonRpcTransformations.apply(service), channel).compile
 }
 
 private class ClientStub[Alg[_[_, _, _, _, _]], F[_]: Monadic](val service: Service[Alg], channel: Channel[F]) {

modules/smithy4s/src/main/scala/jsonrpclib/smithy4sinterop/JsonPayloadTransformation.scala

@@ -0,0 +1,21 @@
+package jsonrpclib.smithy4sinterop
+
+import jsonrpclib.JsonPayload
+import smithy4s.~>
+import smithy4s.Schema
+import smithy4s.Schema.StructSchema
+
+private[jsonrpclib] object JsonPayloadTransformation extends (Schema ~> Schema) {
+
+  def apply[A0](fa: Schema[A0]): Schema[A0] =
+    fa match {
+      case struct: StructSchema[b] =>
+        struct.fields
+          .collectFirst {
+            case field if field.hints.has[JsonPayload] =>
+              field.schema.biject[b]((f: Any) => struct.make(Vector(f)))(field.get)
+          }
+          .getOrElse(fa)
+      case _ => fa
+    }
+}

modules/smithy4s/src/main/scala/jsonrpclib/smithy4sinterop/JsonRpcTransformations.scala

@@ -0,0 +1,33 @@
+package jsonrpclib.smithy4sinterop
+
+import smithy4s.~>
+import smithy4s.schema.ErrorSchema
+import smithy4s.schema.OperationSchema
+import smithy4s.Endpoint
+import smithy4s.Schema
+import smithy4s.Service
+
+private[jsonrpclib] object JsonRpcTransformations {
+
+  def apply[Alg[_[_, _, _, _, _]]]: Service[Alg] => Service[Alg] =
+    _.toBuilder
+      .mapEndpointEach(
+        Endpoint.mapSchema(
+          OperationSchema
+            .mapInputK(JsonPayloadTransformation)
+            .andThen(OperationSchema.mapOutputK(JsonPayloadTransformation))
+            .andThen(OperationSchema.mapErrorK(errorTransformation))
+        )
+      )
+      .build
+
+  private val payloadTransformation: Schema ~> Schema = Schema
+    .transformTransitivelyK(JsonPayloadTransformation)
+
+  private val errorTransformation: ErrorSchema ~> ErrorSchema =
+    new smithy4s.kinds.PolyFunction[ErrorSchema, ErrorSchema] {
+      def apply[A](e: ErrorSchema[A]): ErrorSchema[A] = {
+        payloadTransformation(e.schema).error(e.unliftError)(e.liftError.unlift)
+      }
+    }
+}

modules/smithy4s/src/main/scala/jsonrpclib/smithy4sinterop/ServerEndpoints.scala

@@ -32,8 +32,9 @@ object ServerEndpoints {
   def apply[Alg[_[_, _, _, _, _]], F[_]](
       impl: FunctorAlgebra[Alg, F]
   )(implicit service: Service[Alg], F: Monadic[F]): List[Endpoint[F]] = {
-    val interpreter: service.FunctorInterpreter[F] = service.toPolyFunction(impl)
-    service.endpoints.toList.flatMap { smithy4sEndpoint =>
+    val transformedService = JsonRpcTransformations.apply(service)
+    val interpreter: transformedService.FunctorInterpreter[F] = transformedService.toPolyFunction(impl)
+    transformedService.endpoints.toList.flatMap { smithy4sEndpoint =>
       EndpointSpec
         .fromHints(smithy4sEndpoint.hints)
         .map { endpointSpec =>

project/plugins.sbt

@@ -14,6 +14,6 @@ addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "2.3.1")
 
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.4")
 
-addSbtPlugin("com.disneystreaming.smithy4s" % "smithy4s-sbt-codegen" % "0.18.35")
+addSbtPlugin("com.disneystreaming.smithy4s" % "smithy4s-sbt-codegen" % "0.18.36")
 
 addDependencyTreePlugin