Await WakuRelay publish on node (#313)

* Await WakuRelay publish on node

* Reflect 'await' change on CHANGELOG

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## Next version
+
+- Calls to `publish` a message on `wakunode2` now `await` instead of `discard` dispatched [`WakuRelay`](https://github.com/vacp2p/specs/blob/master/specs/waku/v2/waku-relay.md) procedures
+
 ## 2020-11-30 v0.1
 
 Initial beta release.

examples/v2/basic2.nim

@@ -40,7 +40,7 @@ proc runBackground() {.async.} =
   # Publish to a topic
   let payload = cast[seq[byte]]("hello world")
   let message = WakuMessage(payload: payload, contentTopic: ContentTopic(1))
-  node.publish(topic, message)
+  await node.publish(topic, message)
 
 # TODO Await with try/except here
 discard runBackground()

examples/v2/chat2.nim

@@ -94,14 +94,14 @@ proc publish(c: Chat, line: string) =
     if encodedPayload.isOk():
       let message = WakuMessage(payload: encodedPayload.get(),
         contentTopic: DefaultContentTopic, version: version)
-      c.node.publish(DefaultTopic, message)
+      asyncSpawn c.node.publish(DefaultTopic, message)
     else:
       warn "Payload encoding failed", error = encodedPayload.error
   else:
     # No payload encoding/encryption from Waku
     let message = WakuMessage(payload: line.toBytes(),
       contentTopic: DefaultContentTopic, version: 0)
-    c.node.publish(DefaultTopic, message)
+    asyncSpawn c.node.publish(DefaultTopic, message)
 
 # TODO This should read or be subscribe handler subscribe
 proc readAndPrint(c: Chat) {.async.} =

tests/v2/test_jsonrpc_waku.nim

@@ -156,7 +156,7 @@ procSuite "Waku v2 JSON-RPC API":
       response == true
 
     # Now publish a message on node1 and see if we receive it on node3
-    node1.publish(pubSubTopic, message)
+    await node1.publish(pubSubTopic, message)
 
     await sleepAsync(2000.millis)
     

tests/v2/test_wakunode.nim

@@ -57,7 +57,7 @@ procSuite "WakuNode":
 
     await sleepAsync(2000.millis)
 
-    node.publish(pubSubTopic, message)
+    await node.publish(pubSubTopic, message)
 
     check:
       (await completionFut.withTimeout(5.seconds)) == true
@@ -120,7 +120,7 @@ procSuite "WakuNode":
     await sleepAsync(2000.millis)
 
     info "Waking up and publishing"
-    node2.publish(pubSubTopic, message)
+    await node2.publish(pubSubTopic, message)
 
     check:
       (await completionFut.withTimeout(5.seconds)) == true
@@ -243,7 +243,7 @@ procSuite "WakuNode":
     await node3.subscribe(pubSubTopic, relayHandler)
     await sleepAsync(2000.millis)
 
-    node1.publish(pubSubTopic, message)
+    await node1.publish(pubSubTopic, message)
     await sleepAsync(2000.millis)
 
     check:

waku/v2/node/jsonrpc/relay_api.nim

@@ -34,9 +34,12 @@ proc installRelayApiHandlers*(node: WakuNode, rpcsrv: RpcServer) =
     ## Publishes a WakuMessage to a PubSub topic
     debug "post_waku_v2_relay_v1_message"
 
-    node.publish(topic, message.toWakuMessage(version = 0))
-
-    return true
+    if (await node.publish(topic, message.toWakuMessage(version = 0)).withTimeout(futTimeout)):
+      # Successfully published message
+      return true
+    else:
+      # Failed to publish message to topic
+      raise newException(ValueError, "Failed to publish to topic " & topic)
 
   rpcsrv.rpc("get_waku_v2_relay_v1_messages") do(topic: string) -> seq[WakuMessage]:
     ## Returns all WakuMessages received on a PubSub topic since the

waku/v2/node/rpc/wakurpc.nim

@@ -33,7 +33,7 @@ proc setupWakuRPC*(node: WakuNode, rpcsrv: RpcServer) =
       warn "waku_publish decode error", msg=msg
 
     debug "waku_publish", topic=topic, payload=payload, msg=msg[]
-    node.publish(topic, msg[])
+    await node.publish(topic, msg[])
     return true
     #if not result:
     #  raise newException(ValueError, "Message could not be posted")

waku/v2/node/wakunode2.nim

@@ -216,7 +216,7 @@ proc unsubscribe*(node: WakuNode, request: FilterRequest) {.async, gcsafe.} =
   node.filters.removeContentFilters(request.contentFilters)
 
 
-proc publish*(node: WakuNode, topic: Topic, message: WakuMessage) =
+proc publish*(node: WakuNode, topic: Topic, message: WakuMessage) {.async, gcsafe.} =
   ## Publish a `WakuMessage` to a PubSub topic. `WakuMessage` should contain a
   ## `contentTopic` field for light node functionality. This field may be also
   ## be omitted.
@@ -229,8 +229,7 @@ proc publish*(node: WakuNode, topic: Topic, message: WakuMessage) =
   debug "publish", topic=topic, contentTopic=message.contentTopic
   let data = message.encode().buffer
 
-  # XXX Consider awaiting here
-  discard wakuRelay.publish(topic, data)
+  discard await wakuRelay.publish(topic, data)
 
 proc query*(node: WakuNode, query: HistoryQuery, handler: QueryHandlerFunc) {.async, gcsafe.} =
   ## Queries known nodes for historical messages. Triggers the handler whenever a response is received.