diff --git a/rslib/build.rs b/rslib/build.rs
index 41e768a09..9722afc41 100644
--- a/rslib/build.rs
+++ b/rslib/build.rs
@@ -104,7 +104,7 @@ pub enum BackendMethod {
 "#,
     );
     for (idx, method) in service.methods.iter().enumerate() {
-        write!(buf, "    {} = {},\n", method.proto_name, idx + 1).unwrap();
+        writeln!(buf, "    {} = {},", method.proto_name, idx + 1).unwrap();
     }
     buf.push_str("}\n\n");
 }
diff --git a/rslib/src/findreplace.rs b/rslib/src/findreplace.rs
index 32368cc19..43ee636d4 100644
--- a/rslib/src/findreplace.rs
+++ b/rslib/src/findreplace.rs
@@ -137,7 +137,7 @@ mod test {
                 "Text".into()
             ]
         );
-        let cnt = col.find_and_replace(nids.clone(), "BBB", "ccc", Some("Front".into()))?;
+        let cnt = col.find_and_replace(nids, "BBB", "ccc", Some("Front".into()))?;
         // still 2, as the caller is expected to provide only note ids that have
         // that field, and if we can't find the field we fall back on all fields
         assert_eq!(cnt, 2);
diff --git a/rslib/src/media/changetracker.rs b/rslib/src/media/changetracker.rs
index a68d9e4d7..9dac17115 100644
--- a/rslib/src/media/changetracker.rs
+++ b/rslib/src/media/changetracker.rs
@@ -297,7 +297,7 @@ mod test {
                 entry,
                 MediaEntry {
                     fname: "file.jpg".into(),
-                    sha1: Some(sha1_of_data("hello".as_bytes())),
+                    sha1: Some(sha1_of_data(b"hello")),
                     mtime: f1
                         .metadata()?
                         .modified()?
@@ -331,7 +331,7 @@ mod test {
                 ctx.get_entry("file.jpg")?.unwrap(),
                 MediaEntry {
                     fname: "file.jpg".into(),
-                    sha1: Some(sha1_of_data("hello1".as_bytes())),
+                    sha1: Some(sha1_of_data(b"hello1")),
                     mtime: f1
                         .metadata()?
                         .modified()?
diff --git a/rslib/src/media/check.rs b/rslib/src/media/check.rs
index 1c2a487e1..6866c4df5 100644
--- a/rslib/src/media/check.rs
+++ b/rslib/src/media/check.rs
@@ -519,7 +519,7 @@ fn extract_latex_refs(note: &Note, seen_files: &mut HashSet<String>, svg: bool)
 
 #[cfg(test)]
 pub(crate) mod test {
-    pub(crate) const MEDIACHECK_ANKI2: &'static [u8] =
+    pub(crate) const MEDIACHECK_ANKI2: &[u8] =
         include_bytes!("../../tests/support/mediacheck.anki2");
 
     use crate::collection::{open_collection, Collection};
diff --git a/rslib/src/media/database.rs b/rslib/src/media/database.rs
index 1ce500567..03cd8def9 100644
--- a/rslib/src/media/database.rs
+++ b/rslib/src/media/database.rs
@@ -279,7 +279,7 @@ mod test {
             assert_eq!(ctx.get_entry("test.mp3")?.unwrap(), entry);
 
             // update it
-            entry.sha1 = Some(sha1_of_data("hello".as_bytes()));
+            entry.sha1 = Some(sha1_of_data(b"hello"));
             entry.mtime = 123;
             entry.sync_required = true;
             ctx.set_entry(&entry)?;
diff --git a/rslib/src/media/files.rs b/rslib/src/media/files.rs
index 563071537..763cdb47c 100644
--- a/rslib/src/media/files.rs
+++ b/rslib/src/media/files.rs
@@ -442,7 +442,7 @@ mod test {
 
     #[test]
     fn add_hash_suffix() {
-        let hash = sha1_of_data("hello".as_bytes());
+        let hash = sha1_of_data(b"hello");
         assert_eq!(
             add_hash_suffix_to_file_stem("test.jpg", &hash).as_str(),
             "test-aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d.jpg"
@@ -455,22 +455,22 @@ mod test {
         let dpath = dir.path();
 
         // no existing file case
-        let h1 = sha1_of_data("hello".as_bytes());
+        let h1 = sha1_of_data(b"hello");
         assert_eq!(
-            add_data_to_folder_uniquely(dpath, "test.mp3", "hello".as_bytes(), h1).unwrap(),
+            add_data_to_folder_uniquely(dpath, "test.mp3", b"hello", h1).unwrap(),
             "test.mp3"
         );
 
         // same contents case
         assert_eq!(
-            add_data_to_folder_uniquely(dpath, "test.mp3", "hello".as_bytes(), h1).unwrap(),
+            add_data_to_folder_uniquely(dpath, "test.mp3", b"hello", h1).unwrap(),
             "test.mp3"
         );
 
         // different contents
-        let h2 = sha1_of_data("hello1".as_bytes());
+        let h2 = sha1_of_data(b"hello1");
         assert_eq!(
-            add_data_to_folder_uniquely(dpath, "test.mp3", "hello1".as_bytes(), h2).unwrap(),
+            add_data_to_folder_uniquely(dpath, "test.mp3", b"hello1", h2).unwrap(),
             "test-88fdd585121a4ccb3d1540527aee53a77c77abb8.mp3"
         );
 
diff --git a/rslib/src/sched/cutoff.rs b/rslib/src/sched/cutoff.rs
index 8483eabb1..5938984d5 100644
--- a/rslib/src/sched/cutoff.rs
+++ b/rslib/src/sched/cutoff.rs
@@ -378,16 +378,16 @@ mod test {
     fn legacy_creation_stamp() {
         let offset = fixed_offset_from_minutes(AEST_MINS_WEST);
 
-        let now = TimestampSecs(offset.ymd(2020, 05, 10).and_hms(9, 30, 30).timestamp());
+        let now = TimestampSecs(offset.ymd(2020, 5, 10).and_hms(9, 30, 30).timestamp());
         assert_eq!(
             v1_creation_date_inner(now, AEST_MINS_WEST),
-            offset.ymd(2020, 05, 10).and_hms(4, 0, 0).timestamp()
+            offset.ymd(2020, 5, 10).and_hms(4, 0, 0).timestamp()
         );
 
-        let now = TimestampSecs(offset.ymd(2020, 05, 10).and_hms(1, 30, 30).timestamp());
+        let now = TimestampSecs(offset.ymd(2020, 5, 10).and_hms(1, 30, 30).timestamp());
         assert_eq!(
             v1_creation_date_inner(now, AEST_MINS_WEST),
-            offset.ymd(2020, 05, 9).and_hms(4, 0, 0).timestamp()
+            offset.ymd(2020, 5, 9).and_hms(4, 0, 0).timestamp()
         );
 
         let crt = v1_creation_date_inner(now, AEST_MINS_WEST);
diff --git a/rslib/src/sync/mod.rs b/rslib/src/sync/mod.rs
index cfe31a802..b2933e22d 100644
--- a/rslib/src/sync/mod.rs
+++ b/rslib/src/sync/mod.rs
@@ -1194,14 +1194,7 @@ mod test {
     fn open_col(ctx: &TestContext, fname: &str) -> Result<Collection> {
         let path = ctx.dir.path().join(fname);
         let i18n = I18n::new(&[""], "", log::terminal());
-        open_collection(
-            path,
-            "".into(),
-            "".into(),
-            false,
-            i18n.clone(),
-            log::terminal(),
-        )
+        open_collection(path, "".into(), "".into(), false, i18n, log::terminal())
     }
 
     async fn upload_download(ctx: &mut TestContext) -> Result<()> {
diff --git a/rslib/src/template.rs b/rslib/src/template.rs
index f1b7c233f..34663d650 100644
--- a/rslib/src/template.rs
+++ b/rslib/src/template.rs
@@ -1141,7 +1141,7 @@ mod test {
         if let FN::Text { ref text } = qnodes[1] {
             assert!(text.contains("card is blank"));
         } else {
-            assert!(false);
+            unreachable!();
         }
     }
 }
diff --git a/rspy/src/lib.rs b/rspy/src/lib.rs
index 50261cbd7..bda030380 100644
--- a/rspy/src/lib.rs
+++ b/rspy/src/lib.rs
@@ -139,7 +139,7 @@ impl Backend {
             let out_obj = PyBytes::new(py, &out_bytes);
             out_obj.into()
         })
-        .map_err(|err_bytes| BackendError::py_err(err_bytes))
+        .map_err(BackendError::py_err)
     }
 
     /// This takes and returns JSON, due to Python's slow protobuf
@@ -149,7 +149,7 @@ impl Backend {
         let out_res = py.allow_threads(move || {
             self.backend
                 .run_db_command_bytes(in_bytes)
-                .map_err(|err_bytes| BackendError::py_err(err_bytes))
+                .map_err(BackendError::py_err)
         });
         let out_bytes = out_res?;
         let out_obj = PyBytes::new(py, &out_bytes);