Fix the scalapb json marshaller for sealed-oneof messages

.appveyor.build.sh

@@ -1,8 +1,8 @@
 #!/bin/bash
 set -eo pipefail
 
-JRE8_URL='https://github.com/AdoptOpenJDK/openjdk8-binaries/releases/download/jdk8u242-b08/OpenJDK8U-jre_x64_linux_hotspot_8u242b08.tar.gz'
-JRE8_VERSION='AdoptOpenJDK-8u242b08'
+JRE8_URL='https://github.com/AdoptOpenJDK/openjdk8-binaries/releases/download/jdk8u282-b08/OpenJDK8U-jre_x64_linux_hotspot_8u282b08.tar.gz'
+JRE8_VERSION='AdoptOpenJDK-8u282b08'
 JRE11_URL='https://github.com/AdoptOpenJDK/openjdk11-binaries/releases/download/jdk-11.0.6%2B10/OpenJDK11U-jre_x64_linux_hotspot_11.0.6_10.tar.gz'
 JRE11_VERSION='AdoptOpenJDK-11.0.6_10'
 JDK14_URL='https://github.com/AdoptOpenJDK/openjdk14-binaries/releases/download/jdk-14%2B36/OpenJDK14U-jdk_x64_linux_hotspot_14_36.tar.gz'

scalapb/scalapb_2.12/build.gradle

@@ -34,6 +34,18 @@ tasks.scaladoc.source "${scalapbProject}/src/main/scala"
 compileScala.targetCompatibility = 1.8
 ScalaCompileOptions.metaClass.useAnt = false
 
+tasks.withType(Test) {
+    useJUnitPlatform {
+        // A workaround for 'java.lang.InternalError: Malformed class name'
+        // when testing scalapb module with Java 8. This bug was fixed in Java 9.
+        // - https://github.com/gradle/gradle/issues/8432
+        // - https://bugs.openjdk.java.net/browse/JDK-8057919
+        if (System.env.TEST_JAVA_VERSION == '8') {
+            exclude("**/*\$*\$*.class")
+        }
+    }
+}
+
 task aggregatedScaladocs(
         type: ScalaDoc,
         description: 'Generate scaladocs from all child projects',

scalapb/scalapb_2.13/build.gradle

@@ -25,6 +25,18 @@ tasks.withType(ScalaCompile) {
     }
 }
 
+tasks.withType(Test) {
+    useJUnitPlatform {
+        // A workaround for 'java.lang.InternalError: Malformed class name'
+        // when testing scalapb module with Java 8. This bug was fixed in Java 9.
+        // - https://github.com/gradle/gradle/issues/8432
+        // - https://bugs.openjdk.java.net/browse/JDK-8057919
+        if (System.env.TEST_JAVA_VERSION == '8') {
+            exclude("**/*\$*\$*.class")
+        }
+    }
+}
+
 sourceSets {
     test {
         scala {

scalapb/scalapb_2.13/src/main/scala/com/linecorp/armeria/common/scalapb/ScalaPbJsonMarshaller.scala

@@ -28,7 +28,7 @@ import java.io.{InputStream, OutputStream}
 import java.util.concurrent.ConcurrentMap
 import scala.io.{Codec, Source}
 import scalapb.json4s.{Parser, Printer}
-import scalapb.{GeneratedMessage, GeneratedMessageCompanion}
+import scalapb.{GeneratedMessage, GeneratedMessageCompanion, GeneratedSealedOneof}
 
 /**
  * A [[com.linecorp.armeria.common.grpc.GrpcJsonMarshaller]] that serializes and deserializes
@@ -39,13 +39,16 @@ final class ScalaPbJsonMarshaller private (
     jsonParser: Parser = jsonDefaultParser
 ) extends GrpcJsonMarshaller {
 
-  override def serializeMessage[A](marshaller: Marshaller[A], message: A, os: OutputStream): Unit = {
-    if (!message.isInstanceOf[GeneratedMessage])
-      throw new IllegalStateException(
-        s"Unexpected message type: ${message.getClass} (expected: ${classOf[GeneratedMessage]})")
-    val msg = message.asInstanceOf[GeneratedMessage]
-    os.write(jsonPrinter.print(msg).getBytes())
-  }
+  override def serializeMessage[A](marshaller: Marshaller[A], message: A, os: OutputStream): Unit =
+    message match {
+      case msg: GeneratedSealedOneof =>
+        os.write(jsonPrinter.print(msg.asMessage).getBytes())
+      case msg: GeneratedMessage =>
+        os.write(jsonPrinter.print(msg).getBytes())
+      case _ =>
+        throw new IllegalStateException(
+          s"Unexpected message type: ${message.getClass} (expected: ${classOf[GeneratedMessage]})")
+    }
 
   override def deserializeMessage[A](marshaller: Marshaller[A], in: InputStream): A = {
     val companion = getMessageCompanion(marshaller)

scalapb/scalapb_2.13/src/test/proto/messages.proto

@@ -27,3 +27,20 @@ message SimpleResponse {
   string message = 1;
   int32 status = 2;
 }
+
+// Copied from https://scalapb.github.io/docs/sealed-oneofs/
+message Expr {
+  oneof sealed_value {
+    Literal lit = 1;
+    Add add = 2;
+  }
+}
+
+message Literal {
+  int32 value = 1;
+}
+
+message Add {
+  Expr left = 1;
+  Expr right = 2;
+}

scalapb/scalapb_2.13/src/test/scala/com/linecorp/armeria/common/scalapb/ScalaPbJsonMarshallerTest.scala

@@ -0,0 +1,43 @@
+package com.linecorp.armeria.common.scalapb
+
+import com.linecorp.armeria.scalapb.testing.messages.{Add, Literal}
+import java.io.ByteArrayOutputStream
+import net.javacrumbs.jsonunit.fluent.JsonFluentAssert.assertThatJson
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.Test
+import scalapb.GeneratedSealedOneof
+
+class ScalaPbJsonMarshallerTest {
+
+  @Test
+  def serializeOneOf(): Unit = {
+    val marshaller = ScalaPbJsonMarshaller()
+    val os = new ByteArrayOutputStream()
+
+    val literal = Literal(10)
+    assertThat(literal).isInstanceOf(classOf[GeneratedSealedOneof])
+    marshaller.serializeMessage(null, literal, os)
+    assertThatJson(new String(os.toByteArray))
+      .isEqualTo("""
+          |{
+          |  "lit": { "value": 10 }
+          |}""".stripMargin)
+
+    os.reset()
+    val add = Add(Literal(1), Literal(2))
+    assertThat(add).isInstanceOf(classOf[GeneratedSealedOneof])
+    marshaller.serializeMessage(null, add, os)
+    assertThatJson(new String(os.toByteArray))
+      .isEqualTo("""
+          |{
+          |  "add": {
+          |    "left": {
+          |      "lit": { "value": 1 }
+          |    },
+          |    "right":{
+          |      "lit":{ "value": 2 }
+          |    }
+          |  }
+          |}""".stripMargin)
+  }
+}