Streamline parquet-avro with avro API

Author: Michel Davit

build.sbt

@@ -1033,8 +1033,8 @@ lazy val `scio-parquet` = project
   .in(file("scio-parquet"))
   .dependsOn(
     `scio-core`,
+    `scio-avro` % "provided",
     `scio-tensorflow` % "provided",
-    `scio-avro` % Test,
     `scio-test` % "test->test"
   )
   .settings(commonSettings)

scio-core/src/main/scala/com/spotify/scio/coders/instances/JavaCoders.scala

@@ -37,7 +37,7 @@ import scala.util.{Failure, Success}
 private[coders] object VoidCoder extends AtomicCoder[Void] {
   override def encode(value: Void, outStream: OutputStream): Unit = ()
 
-  override def decode(inStream: InputStream): Void = ???
+  override def decode(inStream: InputStream): Void = null
 
   override def structuralValue(value: Void): AnyRef = AnyRef
 }