Fix null result

core/src/jsonrpclib/Codec.scala

@@ -16,16 +16,21 @@ object Codec {
  def decode[A](payload: Option[Payload])(implicit codec: Codec[A]): Either[ProtocolError, A] = codec.decode(payload)
 
  implicit def fromJsonCodec[A](implicit jsonCodec: JsonValueCodec[A]): Codec[A] = new Codec[A] {
- def encode(a: A): Payload = Payload(writeToArray(a))
+ def encode(a: A): Payload = {
+ Payload(writeToArray(a))
+ }
 
  def decode(payload: Option[Payload]): Either[ProtocolError, A] = {
  try {
  payload match {
- case Some(Payload(array)) => Right(readFromArray(array))
- case None => Left(ProtocolError.ParseError("Expected to decode a payload"))
+ case Some(Payload.Data(payload)) => Right(readFromArray(payload))
+ case Some(Payload.NullPayload) => Right(readFromArray(nullArray))
+ case None => Left(ProtocolError.ParseError("Expected to decode a payload"))
  }
  } catch { case e: JsonReaderException => Left(ProtocolError.ParseError(e.getMessage())) }
  }
  }
 
+ private val nullArray = "null".getBytes()
+
 }

core/src/jsonrpclib/Payload.scala

@@ -5,26 +5,45 @@ import com.github.plokhotnyuk.jsoniter_scala.core.JsonValueCodec
 import com.github.plokhotnyuk.jsoniter_scala.core.JsonWriter
 
 import java.util.Base64
+import jsonrpclib.Payload.Data
+import jsonrpclib.Payload.NullPayload
 
-final case class Payload(array: Array[Byte]) {
- override def equals(other: Any) = other match {
- case bytes: Payload => java.util.Arrays.equals(array, bytes.array)
- case _ => false
+sealed trait Payload extends Product with Serializable {
+ def stripNull: Option[Payload.Data] = this match {
+ case d @ Data(_) => Some(d)
+ case NullPayload => None
  }
-
- override lazy val hashCode: Int = java.util.Arrays.hashCode(array)
-
- override def toString = Base64.getEncoder.encodeToString(array)
 }
+
 object Payload {
+ def apply(value: Array[Byte]) = {
+ if (value == null) NullPayload
+ else Data(value)
+ }
+ final case class Data(array: Array[Byte]) extends Payload {
+ override def equals(other: Any) = other match {
+ case bytes: Data => java.util.Arrays.equals(array, bytes.array)
+ case _ => false
+ }
+
+ override lazy val hashCode: Int = java.util.Arrays.hashCode(array)
+
+ override def toString = Base64.getEncoder.encodeToString(array)
+ }
+
+ case object NullPayload extends Payload
 
  implicit val payloadJsonValueCodec: JsonValueCodec[Payload] = new JsonValueCodec[Payload] {
  def decodeValue(in: JsonReader, default: Payload): Payload = {
- Payload(in.readRawValAsBytes())
+ Data(in.readRawValAsBytes())
  }
 
  def encodeValue(bytes: Payload, out: JsonWriter): Unit =
- out.writeRawVal(bytes.array)
+ bytes match {
+ case Data(array) => out.writeRawVal(array)
+ case NullPayload => out.writeNull()
+
+ }
 
  def nullValue: Payload = null
  }

core/src/jsonrpclib/internals/RawMessage.scala

@@ -3,11 +3,12 @@ package internals
 
 import com.github.plokhotnyuk.jsoniter_scala.core._
 import com.github.plokhotnyuk.jsoniter_scala.macros.JsonCodecMaker
+import com.github.plokhotnyuk.jsoniter_scala.macros.CodecMakerConfig
 
 private[jsonrpclib] case class RawMessage(
  jsonrpc: String,
  method: Option[String] = None,
- result: Option[Payload] = None,
+ result: Option[Option[Payload]] = None,
  error: Option[ErrorPayload] = None,
  params: Option[Payload] = None,
  id: Option[CallId] = None
@@ -21,7 +22,7 @@ private[jsonrpclib] case class RawMessage(
  case (Some(callId), None) =>
  (error, result) match {
  case (Some(error), _) => Right(OutputMessage.ErrorMessage(callId, error))
- case (_, Some(data)) => Right(OutputMessage.ResponseMessage(callId, data))
+ case (_, Some(data)) => Right(OutputMessage.ResponseMessage(callId, data.getOrElse(Payload.NullPayload)))
  case (None, None) =>
  Left(
  ProtocolError.InvalidRequest(
@@ -48,10 +49,11 @@ private[jsonrpclib] object RawMessage {
  RawMessage(`2.0`, method = Some(method), params = params, id = Some(callId))
  case OutputMessage.ErrorMessage(callId, errorPayload) =>
  RawMessage(`2.0`, error = Some(errorPayload), id = Some(callId))
- case OutputMessage.ResponseMessage(callId, data) => RawMessage(`2.0`, result = Some(data), id = Some(callId))
+ case OutputMessage.ResponseMessage(callId, data) =>
+ RawMessage(`2.0`, result = Some(data.stripNull), id = Some(callId))
  }
 
  implicit val rawMessageJsonValueCodecs: JsonValueCodec[RawMessage] =
- JsonCodecMaker.make
+ JsonCodecMaker.make(CodecMakerConfig.withSkipNestedOptionValues(true))
 
 }

core/test/src-jvm-native/jsonrpclib/RawMessageSpec.scala

@@ -0,0 +1,30 @@
+package jsonrpclib
+
+import munit._
+import com.github.plokhotnyuk.jsoniter_scala.core._
+import internals._
+import jsonrpclib.CallId.NumberId
+import jsonrpclib.OutputMessage.ResponseMessage
+
+class RawMessageSpec() extends FunSuite {
+ test("json parsing with null result") {
+ // This is a perfectly valid response object, as result field has to be present,
+ // but can be null: https://www.jsonrpc.org/specification#response_object
+ val rawMessage = readFromString[RawMessage](""" {"jsonrpc":"2.0","result":null,"id":3} """.trim)
+ assertEquals(
+ rawMessage,
+ RawMessage(jsonrpc = "2.0", result = Some(None), id = Some(NumberId(3)))
+ )
+
+ assertEquals(rawMessage.toMessage, Right(ResponseMessage(NumberId(3), Payload.NullPayload)))
+
+ // This, on the other hand, is an invalid response message, as result field is missing
+ val invalidRawMessage = readFromString[RawMessage](""" {"jsonrpc":"2.0","id":3} """.trim)
+ assertEquals(
+ invalidRawMessage,
+ RawMessage(jsonrpc = "2.0", result = None, id = Some(NumberId(3)))
+ )
+
+ assert(invalidRawMessage.toMessage.isLeft, invalidRawMessage.toMessage)
+ }
+}

fs2/src/jsonrpclib/fs2/lsp.scala

@@ -12,6 +12,8 @@ import java.nio.charset.Charset
 import java.nio.charset.StandardCharsets
 import jsonrpclib.Message
 import jsonrpclib.ProtocolError
+import jsonrpclib.Payload.Data
+import jsonrpclib.Payload.NullPayload
 
 object lsp {
 
@@ -42,11 +44,15 @@ object lsp {
  }
 
  private def writeChunk(payload: Payload): Chunk[Byte] = {
- val size = payload.array.size
- val header = s"Content-Length: ${size}" + "\r\n" * 2
- Chunk.array(header.getBytes()) ++ Chunk.array(payload.array)
+ val bytes = payload match {
+ case Data(array) => array
+ case NullPayload => nullArray
+ }
+ val header = s"Content-Length: ${bytes.size}" + "\r\n" * 2
+ Chunk.array(header.getBytes()) ++ Chunk.array(bytes)
  }
 
+ private val nullArray = "null".getBytes()
  private val returnByte = '\r'.toByte
  private val newlineByte = '\n'.toByte