fix: flaky adding two same ip ephemerals (#177)

* fix: flaky adding two same ip ephemerals
* refactor: handle clippy warning
* refactor: grammar and simplify counting to or

src/p2p/swarm.rs

@@ -251,7 +251,7 @@ mod tests {
         Swarm::listen_on(&mut swarm1, "/ip4/127.0.0.1/tcp/0".parse().unwrap()).unwrap();
 
         let peer1 = async move {
-            while let Some(_) = swarm1.next().now_or_never() {}
+            while swarm1.next().now_or_never().is_some() {}
 
             for l in Swarm::listeners(&swarm1) {
                 tx.send(l.clone()).await.unwrap();

tests/multiple_listening_addresses.rs

@@ -30,8 +30,22 @@ fn multiple_concurrent_ephemeral_listening_addresses_on_same_ip() {
 
         let (first, second) = futures::future::join(first, second).await;
 
-        // one should succeed and other should fail
-        assert_eq!(first.is_ok(), second.is_err());
+        // before we have an Swarm-alike api on the background task to make sure the two futures
+        // (first and second) would attempt to modify the background task before a poll to the
+        // inner swarm, this will produce one or two successes.
+        //
+        // with two attempts without polling the swarm in the between:
+        // assert_eq!(first.is_ok(), second.is_err());
+        //
+        // intuitively it could seem that first will always succeed because it must get the first
+        // attempt to push messages into the queue but not sure if that should be leaned on.
+
+        assert!(
+            first.is_ok() || second.is_ok(),
+            "first: {:?}, second: {:?}",
+            first,
+            second
+        );
     });
 }