fix: code review

examples/tutorial_4_gossipsub.nim

@@ -95,11 +95,8 @@ proc oneNode(node: Node, rng: ref HmacDrbgContext) {.async.} =
     node.gossip.subscribe(
       "metrics",
       proc(topic: string, data: seq[byte]) {.async: (raises: []).} =
-        let m = MetricList.decode(data)
-        if m.isErr:
-          raiseAssert "failed to decode metric"
-        else:
-          echo m
+        let m = MetricList.decode(data).expect("metric can be decoded")
+        echo m
       ,
     )
   else:

libp2p/protocols/pubsub/floodsub.nim

@@ -188,8 +188,6 @@ method init*(f: FloodSub) =
       # This is top-level procedure which will work as separate task, so it
       # do not need to propagate CancelledError.
       trace "Unexpected cancellation in floodsub handler", conn
-    except CatchableError as exc:
-      trace "FloodSub handler leaks an error", description = exc.msg, conn
 
   f.handler = handler
   f.codec = FloodSubCodec

libp2p/protocols/pubsub/gossipsub.nim

@@ -219,8 +219,6 @@ method init*(g: GossipSub) =
       # This is top-level procedure which will work as separate task, so it
       # do not need to propogate CancelledError.
       trace "Unexpected cancellation in gossipsub handler", conn
-    except CatchableError as exc:
-      trace "GossipSub handler leaks an error", description = exc.msg, conn
 
   g.handler = handler
   g.codecs &= GossipSubCodec_12
@@ -490,7 +488,9 @@ proc validateAndRelay(
       )
 
     await handleData(g, topic, msg.data)
-  except CatchableError as exc:
+  except CancelledError as exc:
+    info "validateAndRelay failed", description = exc.msg
+  except PeerRateLimitError as exc:
     info "validateAndRelay failed", description = exc.msg
 
 proc dataAndTopicsIdSize(msgs: seq[Message]): int =

libp2p/protocols/pubsub/pubsub.nim

@@ -602,12 +602,9 @@ method validate*(
     topic = topic, registered = toSeq(p.validators.keys)
   if topic in p.validators:
     trace "running validators for topic", topic = topic
-    try:
-      for validator in p.validators[topic]:
+    p.validators.withValue(topic, validators):
+      for validator in validators[]:
         pending.add(validator(topic, message))
-    except KeyError:
-      raiseAssert "topic checked before"
-
   var valResult = ValidationResult.Accept
   let futs = await allFinished(pending)
   for fut in futs:

libp2p/protocols/pubsub/pubsubpeer.nim

@@ -81,9 +81,7 @@ type
   PubSubPeerEvent* = object
     kind*: PubSubPeerEventKind
 
-  GetConn* = proc(): Future[Connection] {.
-    gcsafe, async: (raises: [GetConnDialError]), raises: []
-  .}
+  GetConn* = proc(): Future[Connection] {.gcsafe, async: (raises: [GetConnDialError]).}
   DropConn* = proc(peer: PubSubPeer) {.gcsafe, raises: [].}
     # have to pass peer as it's unknown during init
   OnEvent* = proc(peer: PubSubPeer, event: PubSubPeerEvent) {.gcsafe, raises: [].}
@@ -211,7 +209,7 @@ proc handle*(p: PubSubPeer, conn: Connection) {.async: (raises: []).} =
     except PeerRateLimitError as exc:
       debug "Peer rate limit exceeded, exiting read while",
         conn, peer = p, description = exc.msg
-    except CatchableError as exc:
+    except LPStreamError as exc:
       debug "Exception occurred in PubSubPeer.handle",
         conn, peer = p, closed = conn.closed, description = exc.msg
     finally:
@@ -220,9 +218,6 @@ proc handle*(p: PubSubPeer, conn: Connection) {.async: (raises: []).} =
     # This is top-level procedure which will work as separate task, so it
     # do not need to propagate CancelledError.
     trace "Unexpected cancellation in PubSubPeer.handle"
-  except CatchableError as exc:
-    trace "Exception occurred in PubSubPeer.handle",
-      conn, peer = p, closed = conn.closed, description = exc.msg
   finally:
     debug "exiting pubsub read loop", conn, peer = p, closed = conn.closed
 
@@ -242,8 +237,6 @@ proc closeSendConn(
       p.onEvent(p, PubSubPeerEvent(kind: event))
   except CancelledError as exc:
     raise exc
-  except CatchableError as exc:
-    debug "Errors during diconnection events", description = exc.msg
   # don't cleanup p.address else we leak some gossip stat table
 
 proc connectOnce(
@@ -294,7 +287,11 @@ proc connectImpl(p: PubSubPeer) {.async: (raises: []).} =
           p.connectedFut.complete()
         return
       await connectOnce(p)
-  except CatchableError as exc: # never cancelled
+  except CancelledError as exc:
+    debug "Could not establish send connection", description = exc.msg
+  except LPError as exc:
+    debug "Could not establish send connection", description = exc.msg
+  except GetConnDialError as exc:
     debug "Could not establish send connection", description = exc.msg
 
 proc connect*(p: PubSubPeer) =

tests/pubsub/testgossipsub.nim

@@ -727,12 +727,7 @@ suite "GossipSub":
         handler = proc(
             topic: string, data: seq[byte]
         ) {.async: (raises: []), closure.} =
-          try:
-            if peerName notin seen:
-              seen[peerName] = 0
-            seen[peerName].inc
-          except KeyError:
-            raiseAssert "seen checked before"
+          seen.mgetOrPut(peerName, 0).inc()
           check topic == "foobar"
           if not seenFut.finished() and seen.len >= runs:
             seenFut.complete()

tests/pubsub/testgossipsub2.nim

@@ -65,15 +65,8 @@ suite "GossipSub":
       var handler: TopicHandler
       closureScope:
         var peerName = $dialer.peerInfo.peerId
-        handler = proc(
-            topic: string, data: seq[byte]
-        ) {.async: (raises: []), closure.} =
-          try:
-            if peerName notin seen:
-              seen[peerName] = 0
-            seen[peerName].inc
-          except KeyError:
-            raiseAssert "seen checked before"
+        handler = proc(topic: string, data: seq[byte]) {.async: (raises: []).} =
+          seen.mgetOrPut(peerName, 0).inc()
           info "seen up", count = seen.len
           check topic == "foobar"
           if not seenFut.finished() and seen.len >= runs:
@@ -282,12 +275,7 @@ suite "GossipSub":
         handler = proc(
             topic: string, data: seq[byte]
         ) {.async: (raises: []), closure.} =
-          try:
-            if peerName notin seen:
-              seen[peerName] = 0
-            seen[peerName].inc
-          except KeyError:
-            raiseAssert "seen checked before"
+          seen.mgetOrPut(peerName, 0).inc()
           check topic == "foobar"
           if not seenFut.finished() and seen.len >= runs:
             seenFut.complete()