rust 1.53.0 updates (#2411)

## Issue Addressed

`make lint` failing on rust 1.53.0.

## Proposed Changes

1.53.0 updates

## Additional Info

I haven't figure out why yet, we were now hitting the recursion limit in a few crates. So I had to add `#![recursion_limit = "256"]` in a few places


Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>

.github/custom/config.toml

@@ -0,0 +1,3 @@
+# Custom Cargo config to be used for the udeps CI job
+[http]
+multiplexing = false

.github/workflows/test-suite.yml

@@ -12,7 +12,7 @@ env:
   # Deny warnings in CI
   RUSTFLAGS: "-D warnings"
   # The Nightly version used for cargo-udeps, might need updating from time to time.
-  PINNED_NIGHTLY: nightly-2021-03-01
+  PINNED_NIGHTLY: nightly-2021-06-09
 jobs:
   target-branch-check:
     name: target-branch-check
@@ -198,6 +198,10 @@ jobs:
       run: rustup toolchain install $PINNED_NIGHTLY
     - name: Install cargo-udeps
       run: cargo install cargo-udeps --locked
+    - name: Create Cargo config dir
+      run: mkdir -p .cargo
+    - name: Install custom Cargo config
+      run: cp -f .github/custom/config.toml .cargo/config.toml
     - name: Run cargo udeps to identify unused crates in the dependency graph
       run: make udeps
     env:

account_manager/src/validator/create.rs

@@ -236,7 +236,7 @@ pub fn cli_run<T: EthSpec>(
             .map_err(|e| {
                 format!(
                     "Error registering validator {}: {:?}",
-                    voting_pubkey.to_hex_string(),
+                    voting_pubkey.as_hex_string(),
                     e
                 )
             })?;
@@ -250,7 +250,7 @@ pub fn cli_run<T: EthSpec>(
             .build()
             .map_err(|e| format!("Unable to build validator directory: {:?}", e))?;
 
-        println!("{}/{}\t{}", i + 1, n, voting_pubkey.to_hex_string());
+        println!("{}/{}\t{}", i + 1, n, voting_pubkey.as_hex_string());
     }
 
     Ok(())

account_manager/src/validator/import.rs

@@ -242,7 +242,7 @@ pub fn cli_run(matches: &ArgMatches, validator_dir: PathBuf) -> Result<(), Strin
             .map_err(|e| {
                 format!(
                     "Error registering validator {}: {:?}",
-                    voting_pubkey.to_hex_string(),
+                    voting_pubkey.as_hex_string(),
                     e
                 )
             })?;

beacon_node/beacon_chain/src/eth1_chain.rs

@@ -762,8 +762,8 @@ mod test {
 
             let eth1_chain = get_eth1_chain();
 
-            assert_eq!(
-                eth1_chain.use_dummy_backend, false,
+            assert!(
+                !eth1_chain.use_dummy_backend,
                 "test should not use dummy backend"
             );
 
@@ -795,8 +795,8 @@ mod test {
             let eth1_chain = get_eth1_chain();
             let max_deposits = <E as EthSpec>::MaxDeposits::to_u64();
 
-            assert_eq!(
-                eth1_chain.use_dummy_backend, false,
+            assert!(
+                !eth1_chain.use_dummy_backend,
                 "test should not use dummy backend"
             );
 
@@ -877,8 +877,8 @@ mod test {
 
             let eth1_chain = get_eth1_chain();
 
-            assert_eq!(
-                eth1_chain.use_dummy_backend, false,
+            assert!(
+                !eth1_chain.use_dummy_backend,
                 "test should not use dummy backend"
             );
 
@@ -901,8 +901,8 @@ mod test {
 
             let eth1_chain = get_eth1_chain();
 
-            assert_eq!(
-                eth1_chain.use_dummy_backend, false,
+            assert!(
+                !eth1_chain.use_dummy_backend,
                 "test should not use dummy backend"
             );
 

beacon_node/beacon_chain/src/state_advance_timer.rs

@@ -353,11 +353,11 @@ mod tests {
     #[test]
     fn lock() {
         let lock = Lock::new();
-        assert_eq!(lock.lock(), false);
-        assert_eq!(lock.lock(), true);
-        assert_eq!(lock.lock(), true);
+        assert!(!lock.lock());
+        assert!(lock.lock());
+        assert!(lock.lock());
         lock.unlock();
-        assert_eq!(lock.lock(), false);
-        assert_eq!(lock.lock(), true);
+        assert!(!lock.lock());
+        assert!(lock.lock());
     }
 }

beacon_node/eth2_libp2p/src/discovery/enr_ext.rs

@@ -88,14 +88,14 @@ impl EnrExt for Enr {
             if let Some(udp) = self.udp() {
                 let mut multiaddr: Multiaddr = ip.into();
                 multiaddr.push(Protocol::Udp(udp));
-                multiaddr.push(Protocol::P2p(peer_id.clone().into()));
+                multiaddr.push(Protocol::P2p(peer_id.into()));
                 multiaddrs.push(multiaddr);
             }
 
             if let Some(tcp) = self.tcp() {
                 let mut multiaddr: Multiaddr = ip.into();
                 multiaddr.push(Protocol::Tcp(tcp));
-                multiaddr.push(Protocol::P2p(peer_id.clone().into()));
+                multiaddr.push(Protocol::P2p(peer_id.into()));
                 multiaddrs.push(multiaddr);
             }
         }
@@ -103,7 +103,7 @@ impl EnrExt for Enr {
             if let Some(udp6) = self.udp6() {
                 let mut multiaddr: Multiaddr = ip6.into();
                 multiaddr.push(Protocol::Udp(udp6));
-                multiaddr.push(Protocol::P2p(peer_id.clone().into()));
+                multiaddr.push(Protocol::P2p(peer_id.into()));
                 multiaddrs.push(multiaddr);
             }
 
@@ -128,7 +128,7 @@ impl EnrExt for Enr {
             if let Some(tcp) = self.tcp() {
                 let mut multiaddr: Multiaddr = ip.into();
                 multiaddr.push(Protocol::Tcp(tcp));
-                multiaddr.push(Protocol::P2p(peer_id.clone().into()));
+                multiaddr.push(Protocol::P2p(peer_id.into()));
                 multiaddrs.push(multiaddr);
             }
         }
@@ -154,7 +154,7 @@ impl EnrExt for Enr {
             if let Some(udp) = self.udp() {
                 let mut multiaddr: Multiaddr = ip.into();
                 multiaddr.push(Protocol::Udp(udp));
-                multiaddr.push(Protocol::P2p(peer_id.clone().into()));
+                multiaddr.push(Protocol::P2p(peer_id.into()));
                 multiaddrs.push(multiaddr);
             }
         }

beacon_node/eth2_libp2p/src/peer_manager/mod.rs

@@ -556,20 +556,18 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
                 if known_meta_data.seq_number < meta_data.seq_number {
                     debug!(self.log, "Updating peer's metadata";
                         "peer_id" => %peer_id, "known_seq_no" => known_meta_data.seq_number, "new_seq_no" => meta_data.seq_number);
-                    peer_info.meta_data = Some(meta_data);
                 } else {
                     debug!(self.log, "Received old metadata";
                         "peer_id" => %peer_id, "known_seq_no" => known_meta_data.seq_number, "new_seq_no" => meta_data.seq_number);
                     // Updating metadata even in this case to prevent storing
                     // incorrect  `metadata.attnets` for a peer
-                    peer_info.meta_data = Some(meta_data);
                 }
             } else {
                 // we have no meta-data for this peer, update
                 debug!(self.log, "Obtained peer's metadata";
                     "peer_id" => %peer_id, "new_seq_no" => meta_data.seq_number);
-                peer_info.meta_data = Some(meta_data);
             }
+            peer_info.meta_data = Some(meta_data);
         } else {
             crit!(self.log, "Received METADATA from an unknown peer";
                 "peer_id" => %peer_id);
@@ -583,11 +581,7 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
             // port is removed, which is assumed to be associated with the discv5 protocol (and
             // therefore irrelevant for other libp2p components).
             let mut out_list = enr.multiaddr();
-            out_list.retain(|addr| {
-                addr.iter()
-                    .find(|v| matches!(v, MProtocol::Udp(_)))
-                    .is_none()
-            });
+            out_list.retain(|addr| !addr.iter().any(|v| matches!(v, MProtocol::Udp(_))));
 
             out_list
         } else {

beacon_node/eth2_libp2p/src/peer_manager/peer_sync_status.rs

@@ -62,14 +62,14 @@ impl PeerSyncStatus {
         matches!(self, PeerSyncStatus::Behind { .. })
     }
 
+    /// Updates the peer's sync status, returning whether the status transitioned.
+    ///
+    /// E.g. returns `true` if the state changed from `Synced` to `Advanced`, but not if
+    /// the status remained `Synced` with different `SyncInfo` within.
     pub fn update(&mut self, new_state: PeerSyncStatus) -> bool {
-        if *self == new_state {
-            *self = new_state;
-            false // state was not updated
-        } else {
-            *self = new_state;
-            true
-        }
+        let changed_status = *self != new_state;
+        *self = new_state;
+        changed_status
     }
 
     pub fn as_str(&self) -> &'static str {

beacon_node/eth2_libp2p/src/rpc/handler.rs

@@ -587,7 +587,7 @@ where
                 match std::mem::replace(&mut info.state, InboundState::Poisoned) {
                     InboundState::Idle(substream) if !deactivated => {
                         if !info.pending_items.is_empty() {
-                            let to_send = std::mem::replace(&mut info.pending_items, vec![]);
+                            let to_send = std::mem::take(&mut info.pending_items);
                             let fut = process_inbound_substream(
                                 substream,
                                 info.remaining_chunks,
@@ -665,8 +665,7 @@ where
                                 // elements
 
                                 if !deactivated && !info.pending_items.is_empty() {
-                                    let to_send =
-                                        std::mem::replace(&mut info.pending_items, vec![]);
+                                    let to_send = std::mem::take(&mut info.pending_items);
                                     let fut = process_inbound_substream(
                                         substream,
                                         info.remaining_chunks,

beacon_node/http_api/src/lib.rs

@@ -1254,7 +1254,6 @@ pub fn serve<T: BeaconChainTypes>(
 
     // GET config/fork_schedule
     let get_config_fork_schedule = config_path
-        .clone()
         .and(warp::path("fork_schedule"))
         .and(warp::path::end())
         .and(chain_filter.clone())
@@ -1268,7 +1267,6 @@ pub fn serve<T: BeaconChainTypes>(
 
     // GET config/spec
     let get_config_spec = config_path
-        .clone()
         .and(warp::path("spec"))
         .and(warp::path::end())
         .and(chain_filter.clone())
@@ -1284,7 +1282,6 @@ pub fn serve<T: BeaconChainTypes>(
 
     // GET config/deposit_contract
     let get_config_deposit_contract = config_path
-        .clone()
         .and(warp::path("deposit_contract"))
         .and(warp::path::end())
         .and(chain_filter.clone())

beacon_node/http_api/tests/tests.rs

@@ -1,4 +1,5 @@
 #![cfg(not(debug_assertions))] // Tests are too slow in debug.
+#![recursion_limit = "256"]
 
 use beacon_chain::{
     test_utils::{AttestationStrategy, BeaconChainHarness, BlockStrategy, EphemeralHarnessType},
@@ -2333,7 +2334,7 @@ async fn poll_events<S: Stream<Item = Result<EventKind<T>, eth2::Error>> + Unpin
     };
 
     tokio::select! {
-            _ = collect_stream_fut => {return events}
+            _ = collect_stream_fut => {events}
             _ = tokio::time::sleep(timeout) => { return events; }
     }
 }

beacon_node/network/src/attestation_service/mod.rs

@@ -559,11 +559,10 @@ impl<T: BeaconChainTypes> AttestationService<T> {
             return;
         }
         // If there are no unsubscription events for `subnet_id`, we unsubscribe immediately.
-        if self
+        if !self
             .unsubscriptions
             .keys()
-            .find(|s| s.subnet_id == subnet_id)
-            .is_none()
+            .any(|s| s.subnet_id == subnet_id)
         {
             // we are not at capacity, unsubscribe from the current subnet.
             debug!(self.log, "Unsubscribing from random subnet"; "subnet_id" => *subnet_id);
@@ -601,11 +600,10 @@ impl<T: BeaconChainTypes> AttestationService<T> {
 
         for subnet_id in to_remove_subnets {
             // If there are no unsubscription events for `subnet_id`, we unsubscribe immediately.
-            if self
+            if !self
                 .unsubscriptions
                 .keys()
-                .find(|s| s.subnet_id == *subnet_id)
-                .is_none()
+                .any(|s| s.subnet_id == *subnet_id)
             {
                 self.events
                     .push_back(AttServiceMessage::Unsubscribe(*subnet_id));

beacon_node/network/src/attestation_service/tests/mod.rs

@@ -147,10 +147,10 @@ async fn get_events<S: Stream<Item = AttServiceMessage> + Unpin>(
     };
 
     tokio::select! {
-        _ = collect_stream_fut => {return events}
+        _ = collect_stream_fut => {events}
         _ = tokio::time::sleep(
         Duration::from_millis(SLOT_DURATION_MILLIS) * num_slots_before_timeout,
-    ) => { return events; }
+    ) => { events }
         }
 }
 

beacon_node/network/src/nat.rs

@@ -83,7 +83,7 @@ pub fn construct_upnp_mappings<T: EthSpec>(
                         "tcp",
                         &log,
                     ).and_then(|_| {
-                        let external_socket = external_ip.as_ref().map(|ip| SocketAddr::new(ip.clone().into(), config.tcp_port)).map_err(|_| ());
+                        let external_socket = external_ip.as_ref().map(|ip| SocketAddr::new((*ip).into(), config.tcp_port)).map_err(|_| ());
                         info!(log, "UPnP TCP route established"; "external_socket" => format!("{}:{}", external_socket.as_ref().map(|ip| ip.to_string()).unwrap_or_else(|_| "".into()), config.tcp_port));
                         external_socket
                     }).ok();

beacon_node/network/src/sync/range_sync/chain.rs

@@ -933,10 +933,10 @@ impl<T: BeaconChainTypes> SyncingChain<T> {
         // check if we have the batch for our optimistic start. If not, request it first.
         // We wait for this batch before requesting any other batches.
         if let Some(epoch) = self.optimistic_start {
-            if !self.batches.contains_key(&epoch) {
+            if let Entry::Vacant(entry) = self.batches.entry(epoch) {
                 if let Some(peer) = idle_peers.pop() {
                     let optimistic_batch = BatchInfo::new(&epoch, EPOCHS_PER_BATCH);
-                    self.batches.insert(epoch, optimistic_batch);
+                    entry.insert(optimistic_batch);
                     self.send_batch(network, epoch, peer)?;
                 }
             }

beacon_node/store/src/hot_cold_store.rs

@@ -285,12 +285,11 @@ impl<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> HotColdDB<E, Hot, Cold>
 
     /// Store a state in the store.
     pub fn put_state(&self, state_root: &Hash256, state: &BeaconState<E>) -> Result<(), Error> {
+        let mut ops: Vec<KeyValueStoreOp> = Vec::new();
         if state.slot < self.get_split_slot() {
-            let mut ops: Vec<KeyValueStoreOp> = Vec::new();
             self.store_cold_state(state_root, &state, &mut ops)?;
             self.cold_db.do_atomically(ops)
         } else {
-            let mut ops: Vec<KeyValueStoreOp> = Vec::new();
             self.store_hot_state(state_root, state, &mut ops)?;
             self.hot_db.do_atomically(ops)
         }

beacon_node/store/src/lib.rs

@@ -251,18 +251,18 @@ mod tests {
         let key = Hash256::random();
         let item = StorableThing { a: 1, b: 42 };
 
-        assert_eq!(store.exists::<StorableThing>(&key).unwrap(), false);
+        assert!(!store.exists::<StorableThing>(&key).unwrap());
 
         store.put(&key, &item).unwrap();
 
-        assert_eq!(store.exists::<StorableThing>(&key).unwrap(), true);
+        assert!(store.exists::<StorableThing>(&key).unwrap());
 
         let retrieved = store.get(&key).unwrap().unwrap();
         assert_eq!(item, retrieved);
 
         store.delete::<StorableThing>(&key).unwrap();
 
-        assert_eq!(store.exists::<StorableThing>(&key).unwrap(), false);
+        assert!(!store.exists::<StorableThing>(&key).unwrap());
 
         assert_eq!(store.get::<StorableThing>(&key).unwrap(), None);
     }
@@ -289,14 +289,14 @@ mod tests {
         let key = Hash256::random();
         let item = StorableThing { a: 1, b: 42 };
 
-        assert_eq!(store.exists::<StorableThing>(&key).unwrap(), false);
+        assert!(!store.exists::<StorableThing>(&key).unwrap());
 
         store.put(&key, &item).unwrap();
 
-        assert_eq!(store.exists::<StorableThing>(&key).unwrap(), true);
+        assert!(store.exists::<StorableThing>(&key).unwrap());
 
         store.delete::<StorableThing>(&key).unwrap();
 
-        assert_eq!(store.exists::<StorableThing>(&key).unwrap(), false);
+        assert!(!store.exists::<StorableThing>(&key).unwrap());
     }
 }

beacon_node/tests/test.rs

@@ -1,4 +1,5 @@
 #![cfg(test)]
+#![recursion_limit = "256"]
 
 use beacon_chain::StateSkipConfig;
 use node_test_rig::{

common/validator_dir/src/builder.rs

@@ -231,7 +231,7 @@ impl<'a> Builder<'a> {
                 if self.store_withdrawal_keystore {
                     // Write the withdrawal password to file.
                     write_password_to_file(
-                        password_dir.join(withdrawal_keypair.pk.to_hex_string()),
+                        password_dir.join(withdrawal_keypair.pk.as_hex_string()),
                         withdrawal_password.as_bytes(),
                     )?;
 

consensus/cached_tree_hash/src/cache_arena.rs

@@ -294,9 +294,8 @@ mod tests {
             "after first push sub should have len {}",
             len
         );
-        assert_eq!(
-            sub.is_empty(arena).expect("should exist"),
-            false,
+        assert!(
+            !sub.is_empty(arena).expect("should exist"),
             "new sub should not be empty"
         );
 
@@ -375,9 +374,8 @@ mod tests {
             0,
             "new sub should have len 0"
         );
-        assert_eq!(
+        assert!(
             sub.is_empty(arena).expect("should exist"),
-            true,
             "new sub should be empty"
         );
 
@@ -397,9 +395,8 @@ mod tests {
             0,
             "new sub should have len 0"
         );
-        assert_eq!(
+        assert!(
             sub_01.is_empty(arena).expect("should exist"),
-            true,
             "new sub should be empty"
         );
 
@@ -409,9 +406,8 @@ mod tests {
             0,
             "new sub should have len 0"
         );
-        assert_eq!(
+        assert!(
             sub_02.is_empty(arena).expect("should exist"),
-            true,
             "new sub should be empty"
         );
 
@@ -432,9 +428,8 @@ mod tests {
             0,
             "new sub should have len 0"
         );
-        assert_eq!(
+        assert!(
             sub_01.is_empty(arena).expect("should exist"),
-            true,
             "new sub should be empty"
         );
 
@@ -446,9 +441,8 @@ mod tests {
             0,
             "new sub should have len 0"
         );
-        assert_eq!(
+        assert!(
             sub_02.is_empty(arena).expect("should exist"),
-            true,
             "new sub should be empty"
         );
 
@@ -474,9 +468,8 @@ mod tests {
                     0,
                     "new sub should have len 0"
                 );
-                assert_eq!(
+                assert!(
                     sub.is_empty(arena).expect("should exist"),
-                    true,
                     "new sub should be empty"
                 );
                 subs.push(sub);
@@ -492,9 +485,8 @@ mod tests {
                 0,
                 "new sub should have len 0"
             );
-            assert_eq!(
+            assert!(
                 sub.is_empty(arena).expect("should exist"),
-                true,
                 "new sub should be empty"
             );
             subs.push(sub);

consensus/types/src/beacon_state/committee_cache/tests.rs

@@ -6,7 +6,7 @@ use crate::{test_utils::*, *};
 fn default_values() {
     let cache = CommitteeCache::default();
 
-    assert_eq!(cache.is_initialized_at(Epoch::new(0)), false);
+    assert!(!cache.is_initialized_at(Epoch::new(0)));
     assert!(&cache.active_validator_indices().is_empty());
     assert_eq!(cache.get_beacon_committee(Slot::new(0), 0), None);
     assert_eq!(cache.get_attestation_duties(0), None);

consensus/types/src/indexed_attestation.rs

@@ -105,10 +105,7 @@ mod tests {
         let indexed_vote_first = create_indexed_attestation(3, 1);
         let indexed_vote_second = create_indexed_attestation(3, 2);
 
-        assert_eq!(
-            indexed_vote_first.is_double_vote(&indexed_vote_second),
-            true
-        )
+        assert!(indexed_vote_first.is_double_vote(&indexed_vote_second))
     }
 
     #[test]
@@ -116,10 +113,7 @@ mod tests {
         let indexed_vote_first = create_indexed_attestation(1, 1);
         let indexed_vote_second = create_indexed_attestation(2, 1);
 
-        assert_eq!(
-            indexed_vote_first.is_double_vote(&indexed_vote_second),
-            false
-        );
+        assert!(!indexed_vote_first.is_double_vote(&indexed_vote_second));
     }
 
     #[test]
@@ -127,10 +121,7 @@ mod tests {
         let indexed_vote_first = create_indexed_attestation(2, 1);
         let indexed_vote_second = create_indexed_attestation(1, 2);
 
-        assert_eq!(
-            indexed_vote_first.is_surround_vote(&indexed_vote_second),
-            true
-        );
+        assert!(indexed_vote_first.is_surround_vote(&indexed_vote_second));
     }
 
     #[test]
@@ -138,10 +129,7 @@ mod tests {
         let indexed_vote_first = create_indexed_attestation(4, 1);
         let indexed_vote_second = create_indexed_attestation(3, 2);
 
-        assert_eq!(
-            indexed_vote_first.is_surround_vote(&indexed_vote_second),
-            true
-        );
+        assert!(indexed_vote_first.is_surround_vote(&indexed_vote_second));
     }
 
     #[test]
@@ -149,10 +137,7 @@ mod tests {
         let indexed_vote_first = create_indexed_attestation(2, 2);
         let indexed_vote_second = create_indexed_attestation(1, 1);
 
-        assert_eq!(
-            indexed_vote_first.is_surround_vote(&indexed_vote_second),
-            false
-        );
+        assert!(!indexed_vote_first.is_surround_vote(&indexed_vote_second));
     }
 
     #[test]
@@ -160,10 +145,7 @@ mod tests {
         let indexed_vote_first = create_indexed_attestation(1, 1);
         let indexed_vote_second = create_indexed_attestation(2, 2);
 
-        assert_eq!(
-            indexed_vote_first.is_surround_vote(&indexed_vote_second),
-            false
-        );
+        assert!(!indexed_vote_first.is_surround_vote(&indexed_vote_second));
     }
 
     ssz_and_tree_hash_tests!(IndexedAttestation<MainnetEthSpec>);

consensus/types/src/validator.rs

@@ -93,10 +93,10 @@ mod tests {
 
         let epoch = Epoch::new(0);
 
-        assert_eq!(v.is_active_at(epoch), false);
-        assert_eq!(v.is_exited_at(epoch), false);
-        assert_eq!(v.is_withdrawable_at(epoch), false);
-        assert_eq!(v.slashed, false);
+        assert!(!v.is_active_at(epoch));
+        assert!(!v.is_exited_at(epoch));
+        assert!(!v.is_withdrawable_at(epoch));
+        assert!(!v.slashed);
     }
 
     #[test]
@@ -108,9 +108,9 @@ mod tests {
             ..Validator::default()
         };
 
-        assert_eq!(v.is_active_at(epoch - 1), false);
-        assert_eq!(v.is_active_at(epoch), true);
-        assert_eq!(v.is_active_at(epoch + 1), true);
+        assert!(!v.is_active_at(epoch - 1));
+        assert!(v.is_active_at(epoch));
+        assert!(v.is_active_at(epoch + 1));
     }
 
     #[test]
@@ -122,9 +122,9 @@ mod tests {
             ..Validator::default()
         };
 
-        assert_eq!(v.is_exited_at(epoch - 1), false);
-        assert_eq!(v.is_exited_at(epoch), true);
-        assert_eq!(v.is_exited_at(epoch + 1), true);
+        assert!(!v.is_exited_at(epoch - 1));
+        assert!(v.is_exited_at(epoch));
+        assert!(v.is_exited_at(epoch + 1));
     }
 
     #[test]
@@ -136,9 +136,9 @@ mod tests {
             ..Validator::default()
         };
 
-        assert_eq!(v.is_withdrawable_at(epoch - 1), false);
-        assert_eq!(v.is_withdrawable_at(epoch), true);
-        assert_eq!(v.is_withdrawable_at(epoch + 1), true);
+        assert!(!v.is_withdrawable_at(epoch - 1));
+        assert!(v.is_withdrawable_at(epoch));
+        assert!(v.is_withdrawable_at(epoch + 1));
     }
 
     ssz_and_tree_hash_tests!(Validator);

crypto/bls/src/generic_public_key.rs

@@ -51,7 +51,7 @@ where
     }
 
     /// Returns `self.serialize()` as a `0x`-prefixed hex string.
-    pub fn to_hex_string(&self) -> String {
+    pub fn as_hex_string(&self) -> String {
         format!("{:?}", self)
     }
 

crypto/bls/src/generic_public_key_bytes.rs

@@ -70,7 +70,7 @@ impl<Pub> GenericPublicKeyBytes<Pub> {
     }
 
     /// Returns `self.serialize()` as a `0x`-prefixed hex string.
-    pub fn to_hex_string(&self) -> String {
+    pub fn as_hex_string(&self) -> String {
         format!("{:?}", self)
     }
 

crypto/eth2_keystore/src/keystore.rs

@@ -230,7 +230,7 @@ impl Keystore {
                 },
                 uuid,
                 path: Some(path),
-                pubkey: keypair.pk.to_hex_string()[2..].to_string(),
+                pubkey: keypair.pk.as_hex_string()[2..].to_string(),
                 version: Version::four(),
                 description: Some(description),
                 name: None,
@@ -261,7 +261,7 @@ impl Keystore {
 
         let keypair = keypair_from_secret(plain_text.as_bytes())?;
         // Verify that the derived `PublicKey` matches `self`.
-        if keypair.pk.to_hex_string()[2..] != self.json.pubkey {
+        if keypair.pk.as_hex_string()[2..] != self.json.pubkey {
             return Err(Error::PublicKeyMismatch);
         }
 

lighthouse/src/main.rs

@@ -1,3 +1,5 @@
+#![recursion_limit = "256"]
+
 mod metrics;
 
 use beacon_node::{get_eth2_network_config, ProductionBeaconNode};

slasher/src/block_queue.rs

@@ -13,7 +13,7 @@ impl BlockQueue {
 
     pub fn dequeue(&self) -> Vec<SignedBeaconBlockHeader> {
         let mut blocks = self.blocks.lock();
-        std::mem::replace(&mut *blocks, vec![])
+        std::mem::take(&mut *blocks)
     }
 
     pub fn len(&self) -> usize {

testing/simulator/src/main.rs

@@ -1,3 +1,5 @@
+#![recursion_limit = "256"]
+
 //! This crate provides a simluation that creates `n` beacon node and validator clients, each with
 //! `v` validators. A deposit contract is deployed at the start of the simulation using a local
 //! `ganache-cli` instance (you must have `ganache-cli` installed and avaliable on your path). All

validator_client/slashing_protection/src/slashing_database.rs

@@ -160,7 +160,7 @@ impl SlashingDatabase {
         let mut stmt = txn.prepare("INSERT INTO validators (public_key) VALUES (?1)")?;
         for pubkey in public_keys {
             if self.get_validator_id_opt(&txn, pubkey)?.is_none() {
-                stmt.execute(&[pubkey.to_hex_string()])?;
+                stmt.execute(&[pubkey.as_hex_string()])?;
             }
         }
         Ok(())
@@ -205,7 +205,7 @@ impl SlashingDatabase {
         Ok(txn
             .query_row(
                 "SELECT id FROM validators WHERE public_key = ?1",
-                params![&public_key.to_hex_string()],
+                params![&public_key.as_hex_string()],
                 |row| row.get(0),
             )
             .optional()?)
@@ -990,11 +990,9 @@ mod tests {
             assert_eq!(db.conn_pool.max_size(), POOL_SIZE);
             assert_eq!(db.conn_pool.connection_timeout(), CONNECTION_TIMEOUT);
             let conn = db.conn_pool.get().unwrap();
-            assert_eq!(
-                conn.pragma_query_value(None, "foreign_keys", |row| { row.get::<_, bool>(0) })
-                    .unwrap(),
-                true
-            );
+            assert!(conn
+                .pragma_query_value(None, "foreign_keys", |row| { row.get::<_, bool>(0) })
+                .unwrap());
             assert_eq!(
                 conn.pragma_query_value(None, "locking_mode", |row| { row.get::<_, String>(0) })
                     .unwrap()

validator_client/src/graffiti_file.rs

@@ -129,13 +129,13 @@ mod tests {
             .write_all(format!("default: {}\n", DEFAULT_GRAFFITI).as_bytes())
             .unwrap();
         graffiti_file
-            .write_all(format!("{}: {}\n", pk1.to_hex_string(), CUSTOM_GRAFFITI1).as_bytes())
+            .write_all(format!("{}: {}\n", pk1.as_hex_string(), CUSTOM_GRAFFITI1).as_bytes())
             .unwrap();
         graffiti_file
-            .write_all(format!("{}: {}\n", pk2.to_hex_string(), CUSTOM_GRAFFITI2).as_bytes())
+            .write_all(format!("{}: {}\n", pk2.as_hex_string(), CUSTOM_GRAFFITI2).as_bytes())
             .unwrap();
         graffiti_file
-            .write_all(format!("{}:{}\n", pk3.to_hex_string(), EMPTY_GRAFFITI).as_bytes())
+            .write_all(format!("{}:{}\n", pk3.as_hex_string(), EMPTY_GRAFFITI).as_bytes())
             .unwrap();
         graffiti_file.flush().unwrap();
         file_name