fix(lightpush): waku lightpush rpc codec support optional fields

waku/v2/protocol/waku_lightpush/client.nim

@@ -42,7 +42,7 @@ proc sendPushRequest(wl: WakuLightPushClient, req: PushRequest, peer: PeerId|Rem
     return err(dialFailure)
   let connection = connOpt.get()
 
-  let rpc = PushRPC(requestId: generateRequestId(wl.rng), request: req)
+  let rpc = PushRPC(requestId: generateRequestId(wl.rng), request: some(req))
   await connection.writeLP(rpc.encode().buffer)
 
   var buffer = await connection.readLp(MaxRpcSize.int)
@@ -53,14 +53,14 @@ proc sendPushRequest(wl: WakuLightPushClient, req: PushRequest, peer: PeerId|Rem
     return err(decodeRpcFailure)
 
   let pushResponseRes = decodeRespRes.get()
-  if pushResponseRes.response == PushResponse():
+  if pushResponseRes.response.isNone():
     waku_lightpush_errors.inc(labelValues = [emptyResponseBodyFailure])
     return err(emptyResponseBodyFailure)
 
-  let response = pushResponseRes.response
+  let response = pushResponseRes.response.get()
   if not response.isSuccess:
-    if response.info != "":
-      return err(response.info)
+    if response.info.isSome():
+      return err(response.info.get())
     else:
       return err("unknown failure")
 

waku/v2/protocol/waku_lightpush/protocol.nim

@@ -45,27 +45,27 @@ proc initProtocolHandler*(wl: WakuLightPush) =
       return
 
     let req = reqDecodeRes.get()
-    if req.request == PushRequest():
+    if req.request.isNone():
       error "invalid lightpush rpc received", error=emptyRequestBodyFailure
       waku_lightpush_errors.inc(labelValues = [emptyRequestBodyFailure])
       return
 
     waku_lightpush_messages.inc(labelValues = ["PushRequest"])
     let
-      pubSubTopic = req.request.pubSubTopic
-      message = req.request.message
+      pubSubTopic = req.request.get().pubSubTopic
+      message = req.request.get().message
     debug "push request", peerId=conn.peerId, requestId=req.requestId, pubsubTopic=pubsubTopic
 
     var response: PushResponse
     let handleRes = await wl.pushHandler(conn.peerId, pubsubTopic, message)
     if handleRes.isOk():
-      response = PushResponse(is_success: true, info: "OK")
+      response = PushResponse(is_success: true, info: some("OK"))
     else:
-      response = PushResponse(is_success: false, info: handleRes.error)
+      response = PushResponse(is_success: false, info: some(handleRes.error))
       waku_lightpush_errors.inc(labelValues = [messagePushFailure])
       error "pushed message handling failed", error=handleRes.error
 
-    let rpc = PushRPC(requestId: req.requestId, response: response)
+    let rpc = PushRPC(requestId: req.requestId, response: some(response))
     await conn.writeLp(rpc.encode().buffer)
 
   wl.handler = handle

waku/v2/protocol/waku_lightpush/rpc.nim

@@ -3,6 +3,8 @@ when (NimMajor, NimMinor) < (1, 4):
 else:
   {.push raises: [].}
 
+import
+  std/options
 import
   ../waku_message
 
@@ -13,9 +15,9 @@ type
 
   PushResponse* = object
     isSuccess*: bool
-    info*: string
+    info*: Option[string]
 
   PushRPC* = object
     requestId*: string
-    request*: PushRequest
-    response*: PushResponse
+    request*: Option[PushRequest]
+    response*: Option[PushResponse]

waku/v2/protocol/waku_lightpush/rpc_codec.nim

@@ -4,6 +4,8 @@ else:
   {.push raises: [].}
 
 
+import
+  std/options
 import
   ../../../common/protobuf,
   ../waku_message,
@@ -27,12 +29,16 @@ proc decode*(T: type PushRequest, buffer: seq[byte]): ProtoResult[T] =
   var rpc = PushRequest()
 
   var pubSubTopic: PubsubTopic
-  discard ?pb.getField(1, pubSubTopic)
+  if not ?pb.getField(1, pubSubTopic):
+    return err(ProtoError.RequiredFieldMissing)
+  else:
     rpc.pubSubTopic = pubSubTopic
 
-  var buf: seq[byte]
-  discard ?pb.getField(2, buf)
-  rpc.message = ?WakuMessage.decode(buf)
+  var messageBuf: seq[byte]
+  if not ?pb.getField(2, messageBuf):
+    return err(ProtoError.RequiredFieldMissing)
+  else:
+    rpc.message = ?WakuMessage.decode(messageBuf)
 
   ok(rpc)
 
@@ -48,15 +54,19 @@ proc encode*(rpc: PushResponse): ProtoBuffer =
 
 proc decode*(T: type PushResponse, buffer: seq[byte]): ProtoResult[T] =
   let pb = initProtoBuffer(buffer)
-  var rpc = PushResponse(isSuccess: false, info: "")
+  var rpc = PushResponse()
 
   var isSuccess: uint64
-  if ?pb.getField(1, isSuccess):
+  if not ?pb.getField(1, isSuccess):
+    return err(ProtoError.RequiredFieldMissing)
+  else:
     rpc.isSuccess = bool(isSuccess)
 
   var info: string
-  discard ?pb.getField(2, info)
-  rpc.info = info
+  if not ?pb.getField(2, info):
+    rpc.info = none(string)
+  else: 
+    rpc.info = some(info)
 
   ok(rpc)
 
@@ -65,8 +75,8 @@ proc encode*(rpc: PushRPC): ProtoBuffer =
   var pb = initProtoBuffer()
   
   pb.write3(1, rpc.requestId)
-  pb.write3(2, rpc.request.encode())
-  pb.write3(3, rpc.response.encode())
+  pb.write3(2, rpc.request.map(encode))
+  pb.write3(3, rpc.response.map(encode))
   pb.finish3()
 
   pb
@@ -76,15 +86,23 @@ proc decode*(T: type PushRPC, buffer: seq[byte]): ProtoResult[T] =
   var rpc = PushRPC()
 
   var requestId: string
-  discard ?pb.getField(1, requestId)
+  if not ?pb.getField(1, requestId):
+    return err(ProtoError.RequiredFieldMissing)
+  else:
     rpc.requestId = requestId
 
   var requestBuffer: seq[byte]
-  discard ?pb.getField(2, requestBuffer)
-  rpc.request = ?PushRequest.decode(requestBuffer)
+  if not ?pb.getField(2, requestBuffer):
+    rpc.request = none(PushRequest)
+  else:
+    let request = ?PushRequest.decode(requestBuffer)
+    rpc.request = some(request)
 
-  var pushBuffer: seq[byte]
-  discard ?pb.getField(3, pushBuffer)
-  rpc.response = ?PushResponse.decode(pushBuffer)
+  var responseBuffer: seq[byte]
+  if not ?pb.getField(3, responseBuffer):
+    rpc.response = none(PushResponse)
+  else:
+    let response = ?PushResponse.decode(responseBuffer)
+    rpc.response = some(response)
 
   ok(rpc)