cleanup clippy warnings (#495)

Co-authored-by: Jane Lusby <jane@zfnd.org>

tower-batch/src/service.rs

@@ -67,7 +67,7 @@ where
 
     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
         // If the inner service has errored, then we error here.
-        if let Err(_) = ready!(self.tx.poll_ready(cx)) {
+        if ready!(self.tx.poll_ready(cx)).is_err() {
             Poll::Ready(Err(self.get_worker_error()))
         } else {
             Poll::Ready(Ok(()))

tower-batch/tests/ed25519.rs

@@ -1,5 +1,6 @@
 use std::{
     future::Future,
+    mem,
     pin::Pin,
     sync::Once,
     task::{Context, Poll},
@@ -24,6 +25,7 @@ pub struct Ed25519Verifier {
     tx: Sender<Result<(), Error>>,
 }
 
+#[allow(clippy::new_without_default)]
 impl Ed25519Verifier {
     pub fn new() -> Self {
         let batch = batch::Verifier::default();
@@ -65,7 +67,7 @@ impl<'msg> Service<BatchControl<Ed25519Item>> for Ed25519Verifier {
             }
             BatchControl::Flush => {
                 tracing::trace!("got flush command");
-                let batch = std::mem::replace(&mut self.batch, batch::Verifier::default());
+                let batch = mem::take(&mut self.batch);
                 let _ = self.tx.send(batch.verify(thread_rng()));
                 Box::pin(async { Ok(()) })
             }
@@ -76,7 +78,7 @@ impl<'msg> Service<BatchControl<Ed25519Item>> for Ed25519Verifier {
 impl Drop for Ed25519Verifier {
     fn drop(&mut self) {
         // We need to flush the current batch in case there are still any pending futures.
-        let batch = std::mem::replace(&mut self.batch, batch::Verifier::default());
+        let batch = mem::take(&mut self.batch);
         let _ = self.tx.send(batch.verify(thread_rng()));
     }
 }