*: Fix clippy warnings (#2615)

core/src/identity/rsa.rs

@@ -263,7 +263,7 @@ impl DerDecodable<'_> for Asn1SubjectPublicKey {
             )));
         }
 
-        let pk_der: Vec<u8> = object.value().into_iter().skip(1).cloned().collect();
+        let pk_der: Vec<u8> = object.value().iter().skip(1).cloned().collect();
         // We don't parse pk_der further as an ASN.1 RsaPublicKey, since
         // we only need the DER encoding for `verify`.
         Ok(Self(PublicKey(pk_der)))

core/src/peer_id.rs

@@ -94,7 +94,7 @@ impl PeerId {
     /// In case the given [`Multiaddr`] ends with `/p2p/<peer-id>`, this function
     /// will return the encapsulated [`PeerId`], otherwise it will return `None`.
     pub fn try_from_multiaddr(address: &Multiaddr) -> Option<PeerId> {
-        address.iter().last().map_or(None, |p| match p {
+        address.iter().last().and_then(|p| match p {
             Protocol::P2p(hash) => PeerId::from_multihash(hash).ok(),
             _ => None,
         })

core/src/peer_record.rs

@@ -89,7 +89,7 @@ impl PeerRecord {
         };
 
         let envelope = SignedEnvelope::new(
-            &key,
+            key,
             String::from(DOMAIN_SEP),
             PAYLOAD_TYPE.as_bytes().to_vec(),
             payload,

core/src/transport/memory.rs

@@ -358,9 +358,9 @@ impl<T> Sink<T> for Chan<T> {
     }
 }
 
-impl<T: AsRef<[u8]>> Into<RwStreamSink<Chan<T>>> for Chan<T> {
-    fn into(self) -> RwStreamSink<Chan<T>> {
-        RwStreamSink::new(self)
+impl<T: AsRef<[u8]>> From<Chan<T>> for RwStreamSink<Chan<T>> {
+    fn from(channel: Chan<T>) -> RwStreamSink<Chan<T>> {
+        RwStreamSink::new(channel)
     }
 }
 

muxers/mplex/src/config.rs

@@ -21,7 +21,7 @@
 use crate::codec::MAX_FRAME_SIZE;
 use std::cmp;
 
-pub(crate) const DEFAULT_MPLEX_PROTOCOL_NAME: &'static [u8] = b"/mplex/6.7.0";
+pub(crate) const DEFAULT_MPLEX_PROTOCOL_NAME: &[u8] = b"/mplex/6.7.0";
 
 /// Configuration for the multiplexer.
 #[derive(Debug, Clone)]

muxers/mplex/src/io.rs

@@ -810,10 +810,10 @@ where
 
     /// Checks whether a substream is open for reading.
     fn can_read(&self, id: &LocalStreamId) -> bool {
-        match self.substreams.get(id) {
-            Some(SubstreamState::Open { .. }) | Some(SubstreamState::SendClosed { .. }) => true,
-            _ => false,
-        }
+        matches!(
+            self.substreams.get(id),
+            Some(SubstreamState::Open { .. }) | Some(SubstreamState::SendClosed { .. })
+        )
     }
 
     /// Sends pending frames, without flushing.

muxers/yamux/src/lib.rs

@@ -252,17 +252,19 @@ impl YamuxConfig {
     /// Creates a new `YamuxConfig` in client mode, regardless of whether
     /// it will be used for an inbound or outbound upgrade.
     pub fn client() -> Self {
-        let mut cfg = Self::default();
-        cfg.mode = Some(yamux::Mode::Client);
-        cfg
+        Self {
+            mode: Some(yamux::Mode::Client),
+            ..Default::default()
+        }
     }
 
     /// Creates a new `YamuxConfig` in server mode, regardless of whether
     /// it will be used for an inbound or outbound upgrade.
     pub fn server() -> Self {
-        let mut cfg = Self::default();
-        cfg.mode = Some(yamux::Mode::Server);
-        cfg
+        Self {
+            mode: Some(yamux::Mode::Server),
+            ..Default::default()
+        }
     }
 
     /// Sets the size (in bytes) of the receive window per substream.

swarm/src/behaviour/either.rs

@@ -227,11 +227,11 @@ where
     ) -> Poll<NetworkBehaviourAction<Self::OutEvent, Self::ConnectionHandler>> {
         let event = match self {
             Either::Left(behaviour) => futures::ready!(behaviour.poll(cx, params))
-                .map_out(|e| Either::Left(e))
-                .map_handler_and_in(|h| IntoEitherHandler::Left(h), |e| Either::Left(e)),
+                .map_out(Either::Left)
+                .map_handler_and_in(IntoEitherHandler::Left, Either::Left),
             Either::Right(behaviour) => futures::ready!(behaviour.poll(cx, params))
-                .map_out(|e| Either::Right(e))
-                .map_handler_and_in(|h| IntoEitherHandler::Right(h), |e| Either::Right(e)),
+                .map_out(Either::Right)
+                .map_handler_and_in(IntoEitherHandler::Right, Either::Right),
         };
 
         Poll::Ready(event)

swarm/src/connection/pool/concurrent_dial.rs

@@ -60,7 +60,7 @@ where
         let mut pending_dials = pending_dials.into_iter();
 
         let dials = FuturesUnordered::new();
-        while let Some(dial) = pending_dials.next() {
+        for dial in pending_dials.by_ref() {
             dials.push(dial);
             if dials.len() == concurrency_factor.get() as usize {
                 break;
@@ -95,7 +95,7 @@ where
         loop {
             match ready!(self.dials.poll_next_unpin(cx)) {
                 Some((addr, Ok(output))) => {
-                    let errors = std::mem::replace(&mut self.errors, vec![]);
+                    let errors = std::mem::take(&mut self.errors);
                     return Poll::Ready(Ok((addr, output, errors)));
                 }
                 Some((addr, Err(e))) => {
@@ -105,7 +105,7 @@ where
                     }
                 }
                 None => {
-                    return Poll::Ready(Err(std::mem::replace(&mut self.errors, vec![])));
+                    return Poll::Ready(Err(std::mem::take(&mut self.errors)));
                 }
             }
         }

swarm/src/lib.rs

@@ -514,7 +514,7 @@ where
                     };
                     match dial {
                         Ok(fut) => fut
-                            .map(|r| (address, r.map_err(|e| TransportError::Other(e))))
+                            .map(|r| (address, r.map_err(TransportError::Other)))
                             .boxed(),
                         Err(err) => futures::future::ready((address, Err(err))).boxed(),
                     }
@@ -538,7 +538,7 @@ where
             Err((connection_limit, handler)) => {
                 let error = DialError::ConnectionLimit(connection_limit);
                 self.behaviour.inject_dial_failure(None, handler, &error);
-                return Err(error);
+                Err(error)
             }
         }
     }
@@ -800,7 +800,7 @@ where
                         .expect("n + 1 is always non-zero; qed");
                         let non_banned_established = other_established_connection_ids
                             .into_iter()
-                            .filter(|conn_id| !this.banned_peer_connections.contains(&conn_id))
+                            .filter(|conn_id| !this.banned_peer_connections.contains(conn_id))
                             .count();
 
                         log::debug!(
@@ -896,7 +896,7 @@ where
                     if conn_was_reported {
                         let remaining_non_banned = remaining_established_connection_ids
                             .into_iter()
-                            .filter(|conn_id| !this.banned_peer_connections.contains(&conn_id))
+                            .filter(|conn_id| !this.banned_peer_connections.contains(conn_id))
                             .count();
                         this.behaviour.inject_connection_closed(
                             &peer_id,

transports/dns/src/lib.rs

@@ -264,12 +264,14 @@ where
             // dialing attempts as soon as there is another fully resolved
             // address.
             while let Some(addr) = unresolved.pop() {
-                if let Some((i, name)) = addr.iter().enumerate().find(|(_, p)| match p {
+                if let Some((i, name)) = addr.iter().enumerate().find(|(_, p)| {
+                    matches!(
+                        p,
                         Protocol::Dns(_)
                             | Protocol::Dns4(_)
                             | Protocol::Dns6(_)
-                    | Protocol::Dnsaddr(_) => true,
-                    _ => false,
+                            | Protocol::Dnsaddr(_)
+                    )
                 }) {
                     if dns_lookups == MAX_DNS_LOOKUPS {
                         log::debug!("Too many DNS lookups. Dropping unresolved {}.", addr);

transports/noise/src/protocol/x25519.rs

@@ -180,6 +180,12 @@ impl Keypair<X25519> {
     }
 }
 
+impl Default for Keypair<X25519> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 /// Promote a X25519 secret key into a keypair.
 impl From<SecretKey<X25519>> for Keypair<X25519> {
     fn from(secret: SecretKey<X25519>) -> Keypair<X25519> {

transports/noise/src/protocol/x25519_spec.rs

@@ -61,6 +61,12 @@ impl Keypair<X25519Spec> {
     }
 }
 
+impl Default for Keypair<X25519Spec> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 /// Promote a X25519 secret key into a keypair.
 impl From<SecretKey<X25519Spec>> for Keypair<X25519Spec> {
     fn from(secret: SecretKey<X25519Spec>) -> Keypair<X25519Spec> {

transports/tcp/src/lib.rs

@@ -328,6 +328,12 @@ where
     }
 }
 
+impl<T: Provider + Send> Default for GenTcpConfig<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<T> Transport for GenTcpConfig<T>
 where
     T: Provider + Send + 'static,

transports/uds/src/lib.rs

@@ -63,6 +63,12 @@ impl $uds_config {
     }
 }
 
+impl Default for $uds_config {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Transport for $uds_config {
     type Output = $unix_stream;
     type Error = io::Error;

transports/wasm-ext/src/lib.rs

@@ -318,15 +318,15 @@ impl Stream for Listen {
             };
 
             if let Some(addrs) = event.new_addrs() {
-                for addr in addrs.into_iter() {
-                    let addr = js_value_to_addr(&addr)?;
+                for addr in addrs.iter() {
+                    let addr = js_value_to_addr(addr)?;
                     self.pending_events
                         .push_back(ListenerEvent::NewAddress(addr));
                 }
             }
 
             if let Some(upgrades) = event.new_connections() {
-                for upgrade in upgrades.into_iter().cloned() {
+                for upgrade in upgrades.iter().cloned() {
                     let upgrade: ffi::ConnectionEvent = upgrade.into();
                     self.pending_events.push_back(ListenerEvent::Upgrade {
                         local_addr: upgrade.local_addr().parse()?,
@@ -337,8 +337,8 @@ impl Stream for Listen {
             }
 
             if let Some(addrs) = event.expired_addrs() {
-                for addr in addrs.into_iter() {
-                    match js_value_to_addr(&addr) {
+                for addr in addrs.iter() {
+                    match js_value_to_addr(addr) {
                         Ok(addr) => self
                             .pending_events
                             .push_back(ListenerEvent::NewAddress(addr)),