fix(rln-relay): add unit test for bandwidth cutoff

apps/wakunode2/external_config.nim

@@ -214,7 +214,7 @@ type
     rlnRelayBandwidthThreshold* {.
       desc: "Message rate in bytes/sec after which verification of proofs should happen",
       defaultValue: 0 # to maintain backwards compatibility
-      name: "rln-relay-bandwidth-cutff" }: int
+      name: "rln-relay-bandwidth-cutoff" }: int
 
     staticnodes* {.
       desc: "Peer multiaddr to directly connect with. Argument may be repeated."

tests/v2/waku_rln_relay/test_waku_rln_relay.nim

@@ -708,6 +708,62 @@ suite "Waku rln relay":
       msgValidate2 == MessageValidationResult.Spam
       msgValidate3 == MessageValidationResult.Valid
       msgValidate4 == MessageValidationResult.Invalid
+
+  asyncTest "should validate invalid proofs if bandwidth is available":
+    let index = MembershipIndex(5)
+
+    let rlnConf = WakuRlnConfig(rlnRelayDynamic: false,
+                                rlnRelayPubsubTopic: RlnRelayPubsubTopic,
+                                rlnRelayContentTopic: RlnRelayContentTopic,
+                                rlnRelayCredIndex: index.uint,
+                                rlnRelayBandwidthThreshold: 4)
+    let wakuRlnRelayRes = await WakuRlnRelay.new(rlnConf)
+    require:
+      wakuRlnRelayRes.isOk()
+    let wakuRlnRelay = wakuRlnRelayRes.get()
+
+    # get the current epoch time
+    let time = epochTime()
+
+    #  create some messages from the same peer and append rln proof to them, except wm4
+    var
+      # this one will pass through the bandwidth threshold
+      wm1 = WakuMessage(payload: "Spam".toBytes())
+      # this message, will be over the bandwidth threshold, hence has to be verified
+      wm2 = WakuMessage(payload: "Valid message".toBytes())
+      # this message will be over the bandwidth threshold, hence has to be verified, will be false (since no proof)
+      wm3 = WakuMessage(payload: "Invalid message".toBytes())
+      wm4 = WakuMessage(payload: "Spam message".toBytes())
+
+    let
+      proofAdded1 = wakuRlnRelay.appendRLNProof(wm1, time)
+      proofAdded2 = wakuRlnRelay.appendRLNProof(wm2, time+EpochUnitSeconds)
+      proofAdded3 = wakuRlnRelay.appendRLNProof(wm4, time)
+
+    # ensure proofs are added
+    require:
+      proofAdded1
+      proofAdded2
+      proofAdded3
+
+    # validate messages
+    # validateMessage proc checks the validity of the message fields and adds it to the log (if valid)
+    let
+      # this should be no verification, Valid
+      msgValidate1 = wakuRlnRelay.validateMessage(wm1, some(time))
+      # this should be verification, Valid
+      msgValidate2 = wakuRlnRelay.validateMessage(wm2, some(time))
+      # this should be verification, Invalid
+      msgValidate3 = wakuRlnRelay.validateMessage(wm3, some(time))
+      # this should be verification, Spam
+      msgValidate4 = wakuRlnRelay.validateMessage(wm4, some(time))
+
+    check:
+      msgValidate1 == MessageValidationResult.Valid
+      msgValidate2 == MessageValidationResult.Valid
+      msgValidate3 == MessageValidationResult.Invalid
+      msgValidate4 == MessageValidationResult.Spam
+
 
   test "toIDCommitment and toUInt256":
     # create an instance of rln