Remove some unwraps, including one which panicked in production

src/faucet.rs

@@ -5,7 +5,11 @@
 // along with the Discord Faucet library. If not, see <https://mit-license.org/>.
 
 use anyhow::{Error, Result};
-use async_std::{channel::Receiver, sync::RwLock, task::JoinHandle};
+use async_std::{
+    channel::Receiver,
+    sync::{RwLock, RwLockUpgradableReadGuard},
+    task::{sleep, JoinHandle},
+};
 use clap::Parser;
 use ethers::{
     prelude::SignerMiddleware,
@@ -467,17 +471,12 @@ impl Faucet {
     async fn handle_non_faucet_transfer(&self, receipt: &TransactionReceipt) -> Result<()> {
         tracing::debug!("Handling external incoming transfer to {:?}", receipt.to);
         if let Some(receiver) = receipt.to {
-            if self
-                .state
-                .read()
-                .await
-                .clients_being_funded
-                .contains_key(&receiver)
-            {
+            let state = self.state.upgradable_read().await;
+            if state.clients_being_funded.contains_key(&receiver) {
                 let balance = self.balance(receiver).await?;
                 if balance >= self.config.min_funding_balance() {
                     tracing::info!("Funded client {:?} with external transfer", receiver);
-                    let mut state = self.state.write().await;
+                    let mut state = RwLockUpgradableReadGuard::upgrade(state).await;
                     if let Some(transfer_index) =
                         state.transfer_queue.iter().position(|r| r.to() == receiver)
                     {
@@ -511,7 +510,10 @@ impl Faucet {
 
         // Only continue if there's an inflight transfer or the recipient is a client being funded.
         let is_relevant = inflight.is_some()
-            || (tx.to.is_some() && state.clients_being_funded.contains_key(&tx.to.unwrap()));
+            || tx
+                .to
+                .as_ref()
+                .is_some_and(|to| state.clients_being_funded.contains_key(to));
 
         drop(state);
 
@@ -530,13 +532,12 @@ impl Faucet {
 
         tracing::debug!("Got receipt {:?}", receipt);
 
-        if inflight.is_none() {
-            return self.handle_non_faucet_transfer(&receipt).await;
-        }
-
-        let Transfer {
+        let Some(Transfer {
             sender, request, ..
-        } = inflight.unwrap();
+        }) = inflight
+        else {
+            return self.handle_non_faucet_transfer(&receipt).await;
+        };
 
         tracing::info!("Received receipt for {request:?}");
         // Do all external calls before state modifications
@@ -599,18 +600,29 @@ impl Faucet {
     async fn monitor_transactions(&self) -> Result<()> {
         loop {
             let mut stream = match &self.ws_provider {
-                Some(provider) => provider
-                    .subscribe_blocks()
-                    .await
-                    .unwrap()
-                    .filter_map(|block| async move {
-                        if block.hash.is_none() {
-                            tracing::warn!("Received block without hash, ignoring: {block:?}");
-                        }
-                        block.hash
-                    })
-                    .boxed(),
-                None => self.provider.watch_blocks().await.unwrap().boxed(),
+                Some(provider) => match provider.subscribe_blocks().await {
+                    Ok(stream) => stream
+                        .filter_map(|block| async move {
+                            if block.hash.is_none() {
+                                tracing::warn!("Received block without hash, ignoring: {block:?}");
+                            }
+                            block.hash
+                        })
+                        .boxed(),
+                    Err(err) => {
+                        tracing::error!("Error reconnecting to block stream: {err}");
+                        sleep(Duration::from_secs(1)).await;
+                        continue;
+                    }
+                },
+                None => match self.provider.watch_blocks().await {
+                    Ok(stream) => stream.boxed(),
+                    Err(err) => {
+                        tracing::error!("Error reconnecting to block stream: {err}");
+                        sleep(Duration::from_secs(1)).await;
+                        continue;
+                    }
+                },
             };
 
             self.state.write().await.monitoring_started = true;
@@ -641,7 +653,7 @@ impl Faucet {
             // If we get here, the subscription was closed. This happens for example
             // if the RPC server is restarted.
             tracing::warn!("Block subscription closed, will restart ...");
-            async_std::task::sleep(Duration::from_secs(5)).await;
+            sleep(Duration::from_secs(5)).await;
         }
     }