Update for clippy 1.50 (#2193)

## Issue Addressed

NA

## Proposed Changes

Rust 1.50 has landed 🎉

The shiny new `clippy` peers down upon us mere mortals with disgust. Brutish peasants wrapping our `usize`s in superfluous `Option`s... tsk tsk.

I've performed the goat sacrifice and corrected our evil ways in this PR. Tonight we shall pray that Github Actions bestows the almighty green tick upon us.

## Additional Info

NA


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

.github/workflows/test-suite.yml

@@ -24,6 +24,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v1
+    - name: Get latest version of stable Rust
+      run: rustup update stable
     - name: Get latest version of stable Rust
       run: rustup update stable
     - name: Check formatting with cargo fmt
@@ -78,6 +80,8 @@ jobs:
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v1
+    - name: Get latest version of stable Rust
+      run: rustup update stable
     - name: Build the root Dockerfile
       run: docker build .
   eth1-simulator-ubuntu:
@@ -86,6 +90,8 @@ jobs:
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v1
+    - name: Get latest version of stable Rust
+      run: rustup update stable
     - name: Install ganache-cli
       run: sudo npm install -g ganache-cli
     - name: Run the beacon chain sim that starts from an eth1 contract
@@ -96,6 +102,8 @@ jobs:
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v1
+    - name: Get latest version of stable Rust
+      run: rustup update stable
     - name: Install ganache-cli
       run: sudo npm install -g ganache-cli
     - name: Run the beacon chain sim without an eth1 connection
@@ -106,6 +114,8 @@ jobs:
     needs: cargo-fmt
     steps:
       - uses: actions/checkout@v1
+      - name: Get latest version of stable Rust
+        run: rustup update stable
       - name: Install ganache-cli
         run: sudo npm install -g ganache-cli
       - name: Run the syncing simulator
@@ -116,6 +126,8 @@ jobs:
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v1
+    - name: Get latest version of stable Rust
+      run: rustup update stable
     - name: Typecheck benchmark code without running it
       run: make check-benches
   check-consensus:
@@ -124,6 +136,8 @@ jobs:
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v1
+    - name: Get latest version of stable Rust
+      run: rustup update stable
     - name: Typecheck consensus code in strict mode
       run: make check-consensus
   clippy:
@@ -132,6 +146,8 @@ jobs:
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v1
+    - name: Get latest version of stable Rust
+      run: rustup update stable
     - name: Lint code for quality and style with Clippy
       run: make lint
     - name: Certify Cargo.lock freshness
@@ -142,6 +158,8 @@ jobs:
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v1
+    - name: Get latest version of stable Rust
+      run: rustup update stable
     - name: Validate state_processing feature arbitrary-fuzz
       run:  make arbitrary-fuzz
   cargo-audit:
@@ -150,6 +168,8 @@ jobs:
     needs: cargo-fmt
     steps:
     - uses: actions/checkout@v1
+    - name: Get latest version of stable Rust
+      run: rustup update stable
     - name: Run cargo audit to identify known security vulnerabilities reported to the RustSec Advisory Database
       run:  make audit
   cargo-udeps:

Dockerfile

@@ -1,4 +1,4 @@
-FROM rust:1.47.0 AS builder
+FROM rust:1.50.0 AS builder
 RUN apt-get update && apt-get install -y cmake
 COPY . lighthouse
 ARG PORTABLE

account_manager/src/common.rs

@@ -29,7 +29,7 @@ pub fn read_mnemonic_from_cli(
                 })
             })?,
         None => loop {
-            eprintln!("");
+            eprintln!();
             eprintln!("{}", MNEMONIC_PROMPT);
 
             let mnemonic = read_input_from_user(stdin_inputs)?;
@@ -37,7 +37,7 @@ pub fn read_mnemonic_from_cli(
             match Mnemonic::from_phrase(mnemonic.as_str(), Language::English) {
                 Ok(mnemonic_m) => {
                     eprintln!("Valid mnemonic provided.");
-                    eprintln!("");
+                    eprintln!();
                     sleep(Duration::from_secs(1));
                     break mnemonic_m;
                 }

account_manager/src/validator/create.rs

@@ -272,7 +272,7 @@ pub fn read_wallet_password_from_cli(
             .map_err(|e| format!("Unable to read {:?}: {:?}", path, e))
             .map(|bytes| strip_off_newlines(bytes).into()),
         None => {
-            eprintln!("");
+            eprintln!();
             eprintln!("{}", WALLET_PASSWORD_PROMPT);
             let password =
                 PlainText::from(read_password_from_user(stdin_inputs)?.as_ref().to_vec());

account_manager/src/validator/exit.rs

@@ -280,7 +280,7 @@ fn load_voting_keypair(
             .map_err(|e| format!("Error while decrypting keypair: {:?}", e))
     } else {
         // Prompt password from user.
-        eprintln!("");
+        eprintln!();
         eprintln!(
             "{} for validator in {:?}: ",
             PASSWORD_PROMPT, voting_keystore_path
@@ -289,7 +289,7 @@ fn load_voting_keypair(
         match keystore.decrypt_keypair(password.as_ref()) {
             Ok(keypair) => {
                 eprintln!("Password is correct.");
-                eprintln!("");
+                eprintln!();
                 std::thread::sleep(std::time::Duration::from_secs(1)); // Provides nicer UX.
                 Ok(keypair)
             }

account_manager/src/validator/import.rs

@@ -135,12 +135,12 @@ pub fn cli_run(matches: &ArgMatches, validator_dir: PathBuf) -> Result<(), Strin
         let keystore = Keystore::from_json_file(src_keystore)
             .map_err(|e| format!("Unable to read keystore JSON {:?}: {:?}", src_keystore, e))?;
 
-        eprintln!("");
+        eprintln!();
         eprintln!("Keystore found at {:?}:", src_keystore);
-        eprintln!("");
+        eprintln!();
         eprintln!(" - Public key: 0x{}", keystore.pubkey());
         eprintln!(" - UUID: {}", keystore.uuid());
-        eprintln!("");
+        eprintln!();
         eprintln!(
             "If you enter the password it will be stored as plain-text in {} so that it is not \
              required each time the validator client starts.",
@@ -152,7 +152,7 @@ pub fn cli_run(matches: &ArgMatches, validator_dir: PathBuf) -> Result<(), Strin
                 eprintln!("Reuse previous password.");
                 break Some(password);
             }
-            eprintln!("");
+            eprintln!();
             eprintln!("{}", PASSWORD_PROMPT);
 
             let password = read_password_from_user(stdin_inputs)?;
@@ -166,7 +166,7 @@ pub fn cli_run(matches: &ArgMatches, validator_dir: PathBuf) -> Result<(), Strin
             match keystore.decrypt_keypair(password.as_ref()) {
                 Ok(_) => {
                     eprintln!("Password is correct.");
-                    eprintln!("");
+                    eprintln!();
                     sleep(Duration::from_secs(1)); // Provides nicer UX.
                     if reuse_password {
                         previous_password = Some(password.clone());
@@ -234,13 +234,13 @@ pub fn cli_run(matches: &ArgMatches, validator_dir: PathBuf) -> Result<(), Strin
         eprintln!("Successfully updated {}.", CONFIG_FILENAME);
     }
 
-    eprintln!("");
+    eprintln!();
     eprintln!(
         "Successfully imported {} validators ({} skipped).",
         num_imported_keystores,
         keystore_paths.len() - num_imported_keystores
     );
-    eprintln!("");
+    eprintln!();
     eprintln!("WARNING: {}", KEYSTORE_REUSE_WARNING);
 
     Ok(())

account_manager/src/validator/recover.rs

@@ -93,9 +93,9 @@ pub fn cli_run(matches: &ArgMatches, validator_dir: PathBuf) -> Result<(), Strin
     ensure_dir_exists(&validator_dir)?;
     ensure_dir_exists(&secrets_dir)?;
 
-    eprintln!("");
+    eprintln!();
     eprintln!("WARNING: KEY RECOVERY CAN LEAD TO DUPLICATING VALIDATORS KEYS, WHICH CAN LEAD TO SLASHING.");
-    eprintln!("");
+    eprintln!();
 
     let mnemonic = read_mnemonic_from_cli(mnemonic_path, stdin_inputs)?;
 

account_manager/src/wallet/create.rs

@@ -215,7 +215,7 @@ pub fn read_new_wallet_password_from_cli(
             Ok(password)
         }
         None => loop {
-            eprintln!("");
+            eprintln!();
             eprintln!("{}", NEW_WALLET_PASSWORD_PROMPT);
             let password =
                 PlainText::from(read_password_from_user(stdin_inputs)?.as_ref().to_vec());

account_manager/src/wallet/recover.rs

@@ -63,9 +63,9 @@ pub fn cli_run(matches: &ArgMatches, wallet_base_dir: PathBuf) -> Result<(), Str
     let mnemonic_path: Option<PathBuf> = clap_utils::parse_optional(matches, MNEMONIC_FLAG)?;
     let stdin_inputs = matches.is_present(STDIN_INPUTS_FLAG);
 
-    eprintln!("");
+    eprintln!();
     eprintln!("WARNING: KEY RECOVERY CAN LEAD TO DUPLICATING VALIDATORS KEYS, WHICH CAN LEAD TO SLASHING.");
-    eprintln!("");
+    eprintln!();
 
     let mnemonic = read_mnemonic_from_cli(mnemonic_path, stdin_inputs)?;
 

beacon_node/eth2_libp2p/src/behaviour/mod.rs

@@ -893,7 +893,7 @@ impl<TSpec: EthSpec> Behaviour<TSpec> {
         }
 
         // perform gossipsub score updates when necessary
-        while let Poll::Ready(_) = self.update_gossipsub_scores.poll_tick(cx) {
+        while self.update_gossipsub_scores.poll_tick(cx).is_ready() {
             self.peer_manager.update_gossipsub_scores(&self.gossipsub);
         }
 

beacon_node/eth2_libp2p/src/discovery/enr_ext.rs

@@ -29,7 +29,7 @@ pub trait EnrExt {
 /// Extend ENR CombinedPublicKey for libp2p types.
 pub trait CombinedKeyPublicExt {
     /// Converts the publickey into a peer id, without consuming the key.
-    fn into_peer_id(&self) -> PeerId;
+    fn as_peer_id(&self) -> PeerId;
 }
 
 /// Extend ENR CombinedKey for conversion to libp2p keys.
@@ -41,7 +41,7 @@ pub trait CombinedKeyExt {
 impl EnrExt for Enr {
     /// The libp2p `PeerId` for the record.
     fn peer_id(&self) -> PeerId {
-        self.public_key().into_peer_id()
+        self.public_key().as_peer_id()
     }
 
     /// Returns a list of multiaddrs if the ENR has an `ip` and either a `tcp` or `udp` key **or** an `ip6` and either a `tcp6` or `udp6`.
@@ -195,7 +195,7 @@ impl CombinedKeyPublicExt for CombinedPublicKey {
     /// Converts the publickey into a peer id, without consuming the key.
     ///
     /// This is only available with the `libp2p` feature flag.
-    fn into_peer_id(&self) -> PeerId {
+    fn as_peer_id(&self) -> PeerId {
         match self {
             Self::Secp256k1(pk) => {
                 let pk_bytes = pk.to_bytes();

beacon_node/eth2_libp2p/src/peer_manager/mod.rs

@@ -972,7 +972,7 @@ impl<TSpec: EthSpec> Stream for PeerManager<TSpec> {
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
         // perform the heartbeat when necessary
-        while let Poll::Ready(_) = self.heartbeat.poll_tick(cx) {
+        while self.heartbeat.poll_tick(cx).is_ready() {
             self.heartbeat();
         }
 

beacon_node/eth2_libp2p/src/rpc/rate_limiter.rs

@@ -240,7 +240,7 @@ impl Future for RPCRateLimiter {
     type Output = ();
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
-        while let Poll::Ready(_) = self.prune_interval.poll_tick(cx) {
+        while self.prune_interval.poll_tick(cx).is_ready() {
             self.prune();
         }
 

beacon_node/network/src/attestation_service/mod.rs

@@ -584,13 +584,13 @@ impl<T: BeaconChainTypes> AttestationService<T> {
     /// We don't keep track of a specific validator to random subnet, rather the ratio of active
     /// validators to random subnets. So when a validator goes offline, we can simply remove the
     /// allocated amount of random subnets.
-    fn handle_known_validator_expiry(&mut self) -> Result<(), ()> {
+    fn handle_known_validator_expiry(&mut self) {
         let spec = &self.beacon_chain.spec;
         let subnet_count = spec.attestation_subnet_count;
         let random_subnets_per_validator = spec.random_subnets_per_validator;
         if self.known_validators.len() as u64 * random_subnets_per_validator >= subnet_count {
             // have too many validators, ignore
-            return Ok(());
+            return;
         }
 
         let subscribed_subnets = self.random_subnets.keys().cloned().collect::<Vec<_>>();
@@ -616,7 +616,6 @@ impl<T: BeaconChainTypes> AttestationService<T> {
                 .push_back(AttServiceMessage::EnrRemove(*subnet_id));
             self.random_subnets.remove(subnet_id);
         }
-        Ok(())
     }
 }
 

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

@@ -203,7 +203,11 @@ async fn subscribe_current_slot_wait_for_unsubscribe() {
     let events = get_events(&mut attestation_service, None, 1).await;
     assert_matches!(
         events[..3],
-        [AttServiceMessage::DiscoverPeers(_), AttServiceMessage::Subscribe(_any1), AttServiceMessage::EnrAdd(_any3)]
+        [
+            AttServiceMessage::DiscoverPeers(_),
+            AttServiceMessage::Subscribe(_any1),
+            AttServiceMessage::EnrAdd(_any3)
+        ]
     );
 
     // If the long lived and short lived subnets are the same, there should be no more events
@@ -281,7 +285,11 @@ async fn test_same_subnet_unsubscription() {
     let events = get_events(&mut attestation_service, None, 1).await;
     assert_matches!(
         events[..3],
-        [AttServiceMessage::DiscoverPeers(_), AttServiceMessage::Subscribe(_any1), AttServiceMessage::EnrAdd(_any3)]
+        [
+            AttServiceMessage::DiscoverPeers(_),
+            AttServiceMessage::Subscribe(_any1),
+            AttServiceMessage::EnrAdd(_any3)
+        ]
     );
 
     let expected = AttServiceMessage::Subscribe(subnet_id1);

beacon_node/network/src/nat.rs

@@ -52,11 +52,7 @@ pub fn construct_upnp_mappings<T: EthSpec>(
                 // Just use the first IP of the first interface that is not a loopback and not an
                 // ipv6 address.
                 if !interface.is_loopback() {
-                    if let IpAddr::V4(_) = interface.ip() {
-                        Some(interface.ip())
-                    } else {
-                        None
-                    }
+                    interface.ip().is_ipv4().then(|| interface.ip())
                 } else {
                     None
                 }

beacon_node/network/src/service.rs

@@ -219,7 +219,7 @@ impl<T: BeaconChainTypes> NetworkService<T> {
             log: network_log,
         };
 
-        spawn_service(executor, network_service)?;
+        spawn_service(executor, network_service);
 
         Ok((network_globals, network_send))
     }
@@ -228,7 +228,7 @@ impl<T: BeaconChainTypes> NetworkService<T> {
 fn spawn_service<T: BeaconChainTypes>(
     executor: task_executor::TaskExecutor,
     mut service: NetworkService<T>,
-) -> error::Result<()> {
+) {
     let mut exit_rx = executor.exit();
     let mut shutdown_sender = executor.shutdown_sender();
 
@@ -570,8 +570,6 @@ fn spawn_service<T: BeaconChainTypes>(
             metrics::update_bandwidth_metrics(service.libp2p.bandwidth.clone());
         }
     }, "network");
-
-    Ok(())
 }
 
 /// Returns a `Sleep` that triggers shortly after the next change in the beacon chain fork version.

consensus/state_processing/src/per_block_processing/signature_sets.rs

@@ -156,14 +156,14 @@ where
             get_pubkey(proposer_index)
                 .ok_or_else(|| Error::ValidatorUnknown(proposer_index as u64))?,
             spec,
-        )?,
+        ),
         block_header_signature_set(
             state,
             &proposer_slashing.signed_header_2,
             get_pubkey(proposer_index)
                 .ok_or_else(|| Error::ValidatorUnknown(proposer_index as u64))?,
             spec,
-        )?,
+        ),
     ))
 }
 
@@ -173,7 +173,7 @@ fn block_header_signature_set<'a, T: EthSpec>(
     signed_header: &'a SignedBeaconBlockHeader,
     pubkey: Cow<'a, PublicKey>,
     spec: &'a ChainSpec,
-) -> Result<SignatureSet<'a>> {
+) -> SignatureSet<'a> {
     let domain = spec.get_domain(
         signed_header.message.slot.epoch(T::slots_per_epoch()),
         Domain::BeaconProposer,
@@ -183,11 +183,7 @@ fn block_header_signature_set<'a, T: EthSpec>(
 
     let message = signed_header.message.signing_root(domain);
 
-    Ok(SignatureSet::single_pubkey(
-        &signed_header.signature,
-        pubkey,
-        message,
-    ))
+    SignatureSet::single_pubkey(&signed_header.signature, pubkey, message)
 }
 
 /// Returns the signature set for the given `indexed_attestation`.

consensus/swap_or_not_shuffle/src/compute_shuffled_index.rs

@@ -35,18 +35,22 @@ pub fn compute_shuffled_index(
     let mut index = index;
     for round in 0..shuffle_round_count {
         let pivot = bytes_to_int64(&hash_with_round(seed, round)[..]) as usize % list_size;
-        index = do_round(seed, index, pivot, round, list_size)?;
+        index = do_round(seed, index, pivot, round, list_size);
     }
     Some(index)
 }
 
-fn do_round(seed: &[u8], index: usize, pivot: usize, round: u8, list_size: usize) -> Option<usize> {
+fn do_round(seed: &[u8], index: usize, pivot: usize, round: u8, list_size: usize) -> usize {
     let flip = (pivot + (list_size - index)) % list_size;
     let position = max(index, flip);
     let source = hash_with_round_and_position(seed, round, position);
     let byte = source[(position % 256) / 8];
     let bit = (byte >> (position % 8)) % 2;
-    Some(if bit == 1 { flip } else { index })
+    if bit == 1 {
+        flip
+    } else {
+        index
+    }
 }
 
 fn hash_with_round_and_position(seed: &[u8], round: u8, position: usize) -> Hash256 {

consensus/types/src/attester_slashing.rs

@@ -10,7 +10,9 @@ use tree_hash_derive::TreeHash;
 ///
 /// Spec v0.12.1
 #[cfg_attr(feature = "arbitrary-fuzz", derive(arbitrary::Arbitrary))]
-#[derive(Derivative, Debug, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(
+    Derivative, Debug, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom,
+)]
 #[derivative(PartialEq, Eq, Hash(bound = "T: EthSpec"))]
 #[serde(bound = "T: EthSpec")]
 pub struct AttesterSlashing<T: EthSpec> {

consensus/types/src/indexed_attestation.rs

@@ -13,7 +13,9 @@ use tree_hash_derive::TreeHash;
 ///
 /// Spec v0.12.1
 #[cfg_attr(feature = "arbitrary-fuzz", derive(arbitrary::Arbitrary))]
-#[derive(Derivative, Debug, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(
+    Derivative, Debug, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom,
+)]
 #[derivative(PartialEq, Eq)] // to satisfy Clippy's lint about `Hash`
 #[serde(bound = "T: EthSpec")]
 pub struct IndexedAttestation<T: EthSpec> {

consensus/types/src/signed_beacon_block_header.rs

@@ -14,7 +14,9 @@ use tree_hash_derive::TreeHash;
 ///
 /// Spec v0.12.1
 #[cfg_attr(feature = "arbitrary-fuzz", derive(arbitrary::Arbitrary))]
-#[derive(Derivative, Debug, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(
+    Derivative, Debug, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom,
+)]
 #[derivative(PartialEq, Eq)]
 pub struct SignedBeaconBlockHeader {
     pub message: BeaconBlockHeader,

validator_client/src/initialized_validators.rs

@@ -238,29 +238,29 @@ fn unlock_keystore_via_stdin_password(
     keystore: &Keystore,
     keystore_path: &PathBuf,
 ) -> Result<(ZeroizeString, Keypair), Error> {
-    eprintln!("");
+    eprintln!();
     eprintln!(
         "The {} file does not contain either of the following fields for {:?}:",
         CONFIG_FILENAME, keystore_path
     );
-    eprintln!("");
+    eprintln!();
     eprintln!(" - voting_keystore_password");
     eprintln!(" - voting_keystore_password_path");
-    eprintln!("");
+    eprintln!();
     eprintln!(
         "You may exit and update {} or enter a password. \
                             If you choose to enter a password now then this prompt \
                             will be raised next time the validator is started.",
         CONFIG_FILENAME
     );
-    eprintln!("");
+    eprintln!();
     eprintln!("Enter password (or press Ctrl+c to exit):");
 
     loop {
         let password =
             read_password_from_user(USE_STDIN).map_err(Error::UnableToReadPasswordFromUser)?;
 
-        eprintln!("");
+        eprintln!();
 
         match keystore.decrypt_keypair(password.as_ref()) {
             Ok(keystore) => break Ok((password, keystore)),