Add smithy validations

build.sbt

@@ -102,6 +102,18 @@ val smithy = projectMatrix
     smithyTraitCodegenNamespace := "jsonrpclib"
   )
 
+val smithyTests = projectMatrix
+  .in(file("modules/smithy-tests"))
+  .jvmPlatform(Seq(scala213))
+  .dependsOn(smithy)
+  .settings(
+    publish / skip := true,
+    libraryDependencies ++= Seq(
+      "com.disneystreaming" %%% "weaver-cats" % "0.8.4" % Test
+    )
+  )
+  .disablePlugins(MimaPlugin)
+
 lazy val buildTimeProtocolDependency =
   /** By default, smithy4sInternalDependenciesAsJars doesn't contain the jars in the "smithy4s" configuration. We have
     * to add them manually - this is the equivalent of a "% Smithy4s"-scoped dependency.
@@ -137,7 +149,7 @@ val smithy4s = projectMatrix
   )
 
 val smithy4sTests = projectMatrix
-  .in(file("modules") / "smithy4sTests")
+  .in(file("modules") / "smithy4s-tests")
   .jvmPlatform(jvmScalaVersions, commonJvmSettings)
   .jsPlatform(jsScalaVersions)
   .nativePlatform(Seq(scala3))
@@ -251,6 +263,7 @@ val root = project
       exampleServer,
       exampleClient,
       smithy,
+      smithyTests,
       smithy4s,
       smithy4sTests,
       exampleSmithyShared,

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

@@ -0,0 +1,57 @@
+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 JsonNotificationOutputValidatorSpec extends FunSuite {
+  test("no error when a @jsonNotification operation has unit output") {
+    assembleModel(
+      """$version: "2"
+        |namespace test
+        |
+        |use jsonrpclib#jsonNotification
+        |
+        |@jsonNotification("notify")
+        |operation NotifySomething {
+        |}
+        |""".stripMargin
+    )
+    success
+  }
+  test("return an error when a @jsonNotification operation does not have unit output") {
+    val events = eventsWithoutLocations(
+      assembleModel(
+        """$version: "2"
+          |namespace test
+          |
+          |use jsonrpclib#jsonNotification
+          |
+          |@jsonNotification("notify")
+          |operation NotifySomething {
+          |  output:={
+          |    message: String
+          |  }
+          |}
+          |
+          |""".stripMargin
+      )
+    )
+
+    val expected = ValidationEvent
+      .builder()
+      .id("JsonNotificationOutput")
+      .shapeId(ShapeId.fromParts("test", "NotifySomething"))
+      .severity(Severity.ERROR)
+      .message(
+        "Operation marked as @jsonNotification must not return anything, but found `test#NotifySomethingOutput`."
+      )
+      .build()
+
+    assert(events.contains(expected))
+  }
+
+}

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

@@ -0,0 +1,72 @@
+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 JsonRpcOperationValidatorSpec extends FunSuite {
+  test("no error when all operations in @jsonRPC service are properly annotated") {
+    assembleModel(
+      """$version: "2"
+        |namespace test
+        |
+        |use jsonrpclib#jsonRPC
+        |use jsonrpclib#jsonRequest
+        |use jsonrpclib#jsonNotification
+        |
+        |@jsonRPC
+        |service MyService {
+        |  operations: [OpA, OpB]
+        |}
+        |
+        |@jsonRequest("methodA")
+        |operation OpA {}
+        |
+        |@jsonNotification("methodB")
+        |operation OpB {
+        |  output: unit
+        |}
+        |""".stripMargin
+    )
+    success
+  }
+
+  test("return an error when a @jsonRPC service has an operation without @jsonRequest or @jsonNotification") {
+    val events = eventsWithoutLocations(
+      assembleModel(
+        """$version: "2"
+          |namespace test
+          |
+          |use jsonrpclib#jsonRPC
+          |use jsonrpclib#jsonRequest
+          |
+          |@jsonRPC
+          |service MyService {
+          |  operations: [GoodOp, BadOp]
+          |}
+          |
+          |@jsonRequest("good")
+          |operation GoodOp {}
+          |
+          |operation BadOp {} // ❌ missing jsonRequest or jsonNotification
+          |""".stripMargin
+      )
+    )
+
+    val expected =
+      ValidationEvent
+        .builder()
+        .id("JsonRpcOperation")
+        .shapeId(ShapeId.fromParts("test", "BadOp"))
+        .severity(Severity.ERROR)
+        .message(
+          "Operation is part of service `test#MyService` marked with @jsonRPC but is missing @jsonRequest or @jsonNotification."
+        )
+        .build()
+
+    assert(events.contains(expected))
+  }
+}

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

@@ -0,0 +1,27 @@
+package jsonrpclib
+
+import software.amazon.smithy.model.validation.ValidatedResult
+import software.amazon.smithy.model.validation.ValidationEvent
+import software.amazon.smithy.model.Model
+import software.amazon.smithy.model.SourceLocation
+
+import scala.jdk.CollectionConverters._
+
+private object ModelUtils {
+
+  def assembleModel(text: String): ValidatedResult[Model] = {
+    Model
+      .assembler()
+      .discoverModels()
+      .addUnparsedModel(
+        "test.smithy",
+        text
+      )
+      .assemble()
+  }
+
+  def eventsWithoutLocations(result: ValidatedResult[?]): List[ValidationEvent] = {
+    if (!result.isBroken) sys.error("Expected a broken result")
+    result.getValidationEvents.asScala.toList.map(e => e.toBuilder.sourceLocation(SourceLocation.NONE).build())
+  }
+}

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

@@ -0,0 +1,123 @@
+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 UniqueJsonRpcMethodNamesValidatorSpec extends FunSuite {
+  test("no error when all jsonRpc method names are unique within a service") {
+
+    assembleModel(
+      """$version: "2"
+        |namespace test
+        |
+        |use jsonrpclib#jsonRPC
+        |use jsonrpclib#jsonRequest
+        |use jsonrpclib#jsonNotification
+        |
+        |@jsonRPC
+        |service MyService {
+        |  operations: [OpA, OpB]
+        |}
+        |
+        |@jsonRequest("foo")
+        |operation OpA {}
+        |
+        |@jsonNotification("bar")
+        |operation OpB {}
+        |""".stripMargin
+    ).unwrap()
+
+    success
+  }
+  test("return an error when two operations use the same jsonRpc method name in a service") {
+    val events = eventsWithoutLocations(
+      assembleModel(
+        """$version: "2"
+          |namespace test
+          |
+          |use jsonrpclib#jsonRPC
+          |use jsonrpclib#jsonRequest
+          |use jsonrpclib#jsonNotification
+          |
+          |@jsonRPC
+          |service MyService {
+          |  operations: [OpA, OpB]
+          |}
+          |
+          |@jsonRequest("foo")
+          |operation OpA {}
+          |
+          |@jsonNotification("foo")
+          |operation OpB {} // duplicate method name "foo"
+          |""".stripMargin
+      )
+    )
+
+    val expected = ValidationEvent
+      .builder()
+      .id("UniqueJsonRpcMethodNames")
+      .shapeId(ShapeId.fromParts("test", "MyService"))
+      .severity(Severity.ERROR)
+      .message(
+        "Duplicate JSON-RPC method name `foo` in service `test#MyService`. It is used by: test#OpA, test#OpB"
+      )
+      .build()
+
+    assert(events.contains(expected))
+  }
+
+  test("no error if two services use the same operation") {
+    assembleModel(
+      """$version: "2"
+          |namespace test
+          |
+          |use jsonrpclib#jsonRPC
+          |use jsonrpclib#jsonRequest
+          |use jsonrpclib#jsonNotification
+          |
+          |@jsonRPC
+          |service MyService {
+          |  operations: [OpA]
+          |}
+          |
+          |@jsonRPC
+          |service MyOtherService {
+          |  operations: [OpA]
+          |}
+          |
+          |@jsonRequest("foo")
+          |operation OpA {}
+          |
+          |""".stripMargin
+    ).unwrap()
+    success
+  }
+
+  test("no error if two services use the same operation") {
+    assembleModel(
+      """$version: "2"
+        |namespace test
+        |
+        |use jsonrpclib#jsonRequest
+        |use jsonrpclib#jsonNotification
+        |
+        |
+        |service NonJsonRpcService {
+        |  operations: [OpA]
+        |}
+        |
+        |@jsonRequest("foo")
+        |operation OpA {}
+        |
+        |@jsonNotification("foo")
+        |operation OpB {} // duplicate method name "foo"
+        |""".stripMargin
+    ).unwrap()
+    success
+  }
+
+}

modules/smithy/src/main/java/jsonrpclib/validation/JsonNotificationOutputValidator.java

@@ -0,0 +1,32 @@
+package jsonrpclib.validation;
+
+import jsonrpclib.JsonNotificationTrait;
+import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.shapes.ShapeId;
+import software.amazon.smithy.model.validation.AbstractValidator;
+import software.amazon.smithy.model.validation.ValidationEvent;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * Validates that operations marked with @jsonNotification don't have any
+ * output.
+ */
+public class JsonNotificationOutputValidator extends AbstractValidator {
+
+    @Override
+    public List<ValidationEvent> validate(Model model) {
+        return model.getShapesWithTrait(JsonNotificationTrait.ID).stream().flatMap(op -> {
+            ShapeId outputShapeId = op.asOperationShape().orElseThrow().getOutputShape();
+            var outputShape = model.expectShape(outputShapeId);
+            if (outputShape.asStructureShape().map(s -> !s.members().isEmpty()).orElse(true)) {
+                return Stream.of(error(op, String.format(
+                    "Operation marked as @jsonNotification must not return anything, but found `%s`.", outputShapeId)));
+            } else {
+                return Stream.empty();
+            }
+        }).collect(Collectors.toUnmodifiableList());
+    }
+}

modules/smithy/src/main/java/jsonrpclib/validation/JsonRpcOperationValidator.java

@@ -0,0 +1,38 @@
+package jsonrpclib.validation;
+
+import jsonrpclib.JsonNotificationTrait;
+import jsonrpclib.JsonRPCTrait;
+import jsonrpclib.JsonRequestTrait;
+import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.shapes.ServiceShape;
+import software.amazon.smithy.model.shapes.Shape;
+import software.amazon.smithy.model.validation.AbstractValidator;
+import software.amazon.smithy.model.validation.ValidationEvent;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class JsonRpcOperationValidator extends AbstractValidator {
+
+    @Override
+    public List<ValidationEvent> validate(Model model) {
+        return model.getServiceShapes().stream()
+            .filter(service -> service.hasTrait(JsonRPCTrait.class))
+            .flatMap(service -> validateService(model, service))
+            .collect(Collectors.toList());
+    }
+
+    private Stream<ValidationEvent> validateService(Model model, ServiceShape service) {
+        return service.getAllOperations().stream()
+            .map(model::expectShape)
+            .filter(op -> !hasJsonRpcMethod(op))
+            .map(op -> error(op, String.format(
+                "Operation is part of service `%s` marked with @jsonRPC but is missing @jsonRequest or @jsonNotification.", service.getId())));
+    }
+
+    private boolean hasJsonRpcMethod(Shape op) {
+        return op.hasTrait(JsonRequestTrait.ID) || op.hasTrait(JsonNotificationTrait.ID);
+    }
+}
+