diff --git a/src/cache/compat.rs b/src/cache/compat.rs
index e45980b..7c47ba3 100644
--- a/src/cache/compat.rs
+++ b/src/cache/compat.rs
@@ -97,7 +97,7 @@ mod parse {
             metadata.content_type.map(|v| v.0),
             Some(ImageContentType::Jpeg)
         );
-        assert_eq!(metadata.size, Some(117888));
+        assert_eq!(metadata.size, Some(117_888));
         assert_eq!(
             metadata.last_modified.map(|v| v.0),
             Some(DateTime::parse_from_rfc2822(
diff --git a/src/cache/disk.rs b/src/cache/disk.rs
index 75f7ab0..b6fe8c7 100644
--- a/src/cache/disk.rs
+++ b/src/cache/disk.rs
@@ -462,7 +462,7 @@ mod remove_file_handler {
     use tempfile::tempdir;
     use tokio::fs::{create_dir_all, remove_dir_all};
 
-    use super::*;
+    use super::{File, remove_file_handler};
 
     #[tokio::test]
     async fn should_not_panic_on_invalid_path() {
@@ -568,7 +568,7 @@ mod db {
     use sqlx::{Connection, Row, SqliteConnection};
     use std::error::Error;
 
-    use super::*;
+    use super::{Cache, ConnectOptions, DiskCache, FromStr, Ordering, PathBuf, StreamExt, handle_db_get, handle_db_put};
 
     #[tokio::test]
     #[cfg_attr(miri, ignore)]
@@ -639,7 +639,7 @@ mod db {
 
 #[cfg(test)]
 mod md5_hash {
-    use super::*;
+    use super::{Digest, GenericArray, Md5, Md5Hash, Path, PathBuf, TryFrom};
 
     #[test]
     fn to_cache_path() {
diff --git a/src/cache/fs.rs b/src/cache/fs.rs
index 509d9f2..e975a7f 100644
--- a/src/cache/fs.rs
+++ b/src/cache/fs.rs
@@ -469,7 +469,7 @@ mod read_file_compat {
 mod metadata_future {
     use std::{collections::VecDeque, io::ErrorKind};
 
-    use super::*;
+    use super::{AsyncBufRead, AsyncRead, AsyncReadExt, BufReader, Context, Error, MetadataFuture, NewCipher, Pin, Poll, ReadBuf};
     use crate::cache::ImageContentType;
     use chrono::DateTime;
 
@@ -550,7 +550,7 @@ mod metadata_future {
         })?;
 
         assert_eq!(metadata.content_type, Some(ImageContentType::Png));
-        assert_eq!(metadata.content_length, Some(708370));
+        assert_eq!(metadata.content_length, Some(708_370));
         assert_eq!(
             metadata.last_modified,
             Some(DateTime::parse_from_rfc3339("2021-04-13T04:37:41+00:00")?)
@@ -579,7 +579,7 @@ mod metadata_future {
         })?;
 
         assert_eq!(metadata.content_type, Some(ImageContentType::Png));
-        assert_eq!(metadata.content_length, Some(708370));
+        assert_eq!(metadata.content_length, Some(708_370));
         assert_eq!(
             metadata.last_modified,
             Some(DateTime::parse_from_rfc3339("2021-04-13T04:37:41+00:00")?)
@@ -611,7 +611,7 @@ mod metadata_future {
         })?;
 
         assert_eq!(metadata.content_type, Some(ImageContentType::Png));
-        assert_eq!(metadata.content_length, Some(708370));
+        assert_eq!(metadata.content_length, Some(708_370));
         assert_eq!(
             metadata.last_modified,
             Some(DateTime::parse_from_rfc3339("2021-04-13T04:37:41+00:00")?)
diff --git a/src/cache/mem.rs b/src/cache/mem.rs
index 4fbb54d..5258482 100644
--- a/src/cache/mem.rs
+++ b/src/cache/mem.rs
@@ -367,7 +367,7 @@ mod test_util {
             metadata: ImageMetadata,
             on_complete: Sender<CacheEntry>,
         ) -> Result<(), CacheError> {
-            self.put(key.clone(), data.clone(), metadata.clone())
+            self.put(key.clone(), data.clone(), metadata)
                 .await?;
             let on_disk_size = data.len() as u64;
             let _ = on_complete
@@ -438,7 +438,7 @@ mod cache_ops {
             last_modified: None,
         };
         let bytes = Bytes::from_static(b"abcd");
-        let value = CacheValue::new(bytes.clone(), metadata.clone(), 34);
+        let value = CacheValue::new(bytes.clone(), metadata, 34);
 
         // Populate the cache, need to drop the lock else it's considered locked
         // when we actually call the cache
@@ -478,7 +478,7 @@ mod cache_ops {
         {
             let cache = &mut cache.inner;
             cache
-                .put(key.clone(), bytes.clone(), metadata.clone())
+                .put(key.clone(), bytes.clone(), metadata)
                 .await?;
         }
 
@@ -511,7 +511,7 @@ mod cache_ops {
         {
             let cache = &mut cache.inner;
             cache
-                .put(key.clone(), bytes.clone(), metadata.clone())
+                .put(key.clone(), bytes.clone(), metadata)
                 .await?;
         }
 
@@ -557,7 +557,7 @@ mod cache_ops {
         let bytes_len = bytes.len() as u64;
 
         cache
-            .put(key.clone(), bytes.clone(), metadata.clone())
+            .put(key.clone(), bytes.clone(), metadata)
             .await?;
 
         // Because the callback is supposed to let the memory cache insert the
@@ -667,7 +667,7 @@ mod db_listener {
         };
         let bytes = Bytes::from_static(b"abcde");
 
-        cache.put(key_0, bytes.clone(), metadata.clone()).await?;
+        cache.put(key_0, bytes.clone(), metadata).await?;
         cache.put(key_1, bytes.clone(), metadata).await?;
 
         // let the listener run first
@@ -717,6 +717,6 @@ mod mem_threshold {
 
     #[test]
     fn large_amount_cannot_overflow() {
-        assert_eq!(mem_threshold(&Bytes(usize::MAX)), 17524406870024074020);
+        assert_eq!(mem_threshold(&Bytes(usize::MAX)), 17_524_406_870_024_074_020);
     }
 }
diff --git a/src/main.rs b/src/main.rs
index 5c645d0..7321035 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -280,6 +280,7 @@ impl Display for InvalidCombination {
 impl Error for InvalidCombination {}
 
 #[cfg(not(tarpaulin_include))]
+#[allow(clippy::cognitive_complexity)]
 fn print_preamble_and_warnings(args: &Config) -> Result<(), Box<dyn Error>> {
     let build_string = option_env!("VERGEN_GIT_SHA_SHORT")
         .map(|git_sha| format!(" ({})", git_sha))
diff --git a/src/ping.rs b/src/ping.rs
index f23430b..9a86fe3 100644
--- a/src/ping.rs
+++ b/src/ping.rs
@@ -199,14 +199,13 @@ pub async fn update_server_state(
                 }
 
                 if let Some(key) = resp.token_key {
-                    if let Some(key) = base64::decode(&key)
+                    base64::decode(&key)
                         .ok()
                         .and_then(|k| PrecomputedKey::from_slice(&k))
-                    {
-                        write_guard.precomputed_key = key;
-                    } else {
-                        error!("Failed to parse token key: got {}", key);
-                    }
+                        .map_or_else(
+                            || error!("Failed to parse token key: got {}", key),
+                            |key| write_guard.precomputed_key = key,
+                        );
                 }
 
                 if let Some(tls) = resp.tls {
diff --git a/src/routes.rs b/src/routes.rs
index e862efd..acaa494 100644
--- a/src/routes.rs
+++ b/src/routes.rs
@@ -299,7 +299,7 @@ pub fn construct_response(
 
 #[cfg(test)]
 mod token_validation {
-    use super::*;
+    use super::{BASE64_CONFIG, DecodeError, PrecomputedKey, TokenValidationError, Utc, validate_token};
     use sodiumoxide::crypto::box_::precompute;
     use sodiumoxide::crypto::box_::seal_precomputed;
     use sodiumoxide::crypto::box_::{gen_keypair, gen_nonce, PRECOMPUTEDKEYBYTES};
@@ -348,7 +348,7 @@ mod token_validation {
         // Seal with precomputed_2, open with precomputed_1
 
         let data = seal_precomputed(b"hello world", &nonce, &precomputed_2);
-        let data: Vec<u8> = nonce.as_ref().into_iter().copied().chain(data).collect();
+        let data: Vec<u8> = nonce.as_ref().iter().copied().chain(data).collect();
         let data = base64::encode_config(data, BASE64_CONFIG);
 
         let res = validate_token(&precomputed_1, data, "b");
@@ -364,7 +364,7 @@ mod token_validation {
         let nonce = gen_nonce();
 
         let data = seal_precomputed(b"hello world", &nonce, &precomputed);
-        let data: Vec<u8> = nonce.as_ref().into_iter().copied().chain(data).collect();
+        let data: Vec<u8> = nonce.as_ref().iter().copied().chain(data).collect();
         let data = base64::encode_config(data, BASE64_CONFIG);
 
         let res = validate_token(&precomputed, data, "b");
@@ -390,7 +390,7 @@ mod token_validation {
             &nonce,
             &precomputed,
         );
-        let data: Vec<u8> = nonce.as_ref().into_iter().copied().chain(data).collect();
+        let data: Vec<u8> = nonce.as_ref().iter().copied().chain(data).collect();
         let data = base64::encode_config(data, BASE64_CONFIG);
 
         let res = validate_token(&precomputed, data, "b");
@@ -416,7 +416,7 @@ mod token_validation {
             &nonce,
             &precomputed,
         );
-        let data: Vec<u8> = nonce.as_ref().into_iter().copied().chain(data).collect();
+        let data: Vec<u8> = nonce.as_ref().iter().copied().chain(data).collect();
         let data = base64::encode_config(data, BASE64_CONFIG);
 
         let res = validate_token(&precomputed, data, "");
@@ -442,7 +442,7 @@ mod token_validation {
             &nonce,
             &precomputed,
         );
-        let data: Vec<u8> = nonce.as_ref().into_iter().copied().chain(data).collect();
+        let data: Vec<u8> = nonce.as_ref().iter().copied().chain(data).collect();
         let data = base64::encode_config(data, BASE64_CONFIG);
 
         let res = validate_token(&precomputed, data, "b");
diff --git a/src/state.rs b/src/state.rs
index aa11e0e..325038e 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -89,7 +89,6 @@ impl ServerState {
                     if let Some(ref override_url) = config.override_upstream {
                         resp.image_server = override_url.clone();
                         warn!("Upstream URL overridden to: {}", resp.image_server);
-                    } else {
                     }
 
                     info!("This client's URL has been set to {}", resp.url);
diff --git a/src/units.rs b/src/units.rs
index cd0733a..9d9a59f 100644
--- a/src/units.rs
+++ b/src/units.rs
@@ -44,7 +44,7 @@ pub struct Mebibytes(usize);
 impl Mebibytes {
     #[cfg(test)]
     pub fn new(size: usize) -> Self {
-        Mebibytes(size)
+        Self(size)
     }
 }