diff --git a/vegafusion-datafusion-udfs/src/udfs/datetime/str_to_utc_timestamp.rs b/vegafusion-datafusion-udfs/src/udfs/datetime/str_to_utc_timestamp.rs
index be2790d28..cc6f3333c 100644
--- a/vegafusion-datafusion-udfs/src/udfs/datetime/str_to_utc_timestamp.rs
+++ b/vegafusion-datafusion-udfs/src/udfs/datetime/str_to_utc_timestamp.rs
@@ -117,14 +117,14 @@ pub fn parse_datetime_fallback(
     date_str: &str,
     default_input_tz: &Option<chrono_tz::Tz>,
 ) -> Option<DateTime<Utc>> {
-    let mut date_tokens = vec![String::from(""), String::from(""), String::from("")];
-    let mut time_tokens = vec![
+    let mut date_tokens = [String::from(""), String::from(""), String::from("")];
+    let mut time_tokens = [
         String::from(""),
         String::from(""),
         String::from(""),
         String::from(""),
     ];
-    let mut timezone_tokens = vec![String::from(""), String::from("")];
+    let mut timezone_tokens = [String::from(""), String::from("")];
     let mut timezone_sign = ' ';
     let mut date_ind = 0;
     let mut time_ind = 0;
diff --git a/vegafusion-jni/src/lib.rs b/vegafusion-jni/src/lib.rs
index 26e286ccf..5c48b28e5 100644
--- a/vegafusion-jni/src/lib.rs
+++ b/vegafusion-jni/src/lib.rs
@@ -312,11 +312,11 @@ pub unsafe extern "system" fn Java_io_vegafusion_VegaFusionRuntime_innerPreTrans
             }
             Ok(Err(vf_err)) => {
                 let _ = env.throw_new("io/vegafusion/VegaFusionException", vf_err.to_string());
-                return JObject::null().into_raw();
+                JObject::null().into_raw()
             }
             Err(_unwind_err) => {
                 let _ = env.throw_new("io/vegafusion/VegaFusionException", "Uncaught Error");
-                return JObject::null().into_raw();
+                JObject::null().into_raw()
             }
         }
     } else {
@@ -324,6 +324,6 @@ pub unsafe extern "system" fn Java_io_vegafusion_VegaFusionRuntime_innerPreTrans
             "io/vegafusion/VegaFusionException",
             "Failed to parse args to innerPreTransformSpec",
         );
-        return JObject::null().into_raw();
+        JObject::null().into_raw()
     }
 }
diff --git a/vegafusion-python-embed/src/dataframe.rs b/vegafusion-python-embed/src/dataframe.rs
index 92ce298d6..b5d11f6d4 100644
--- a/vegafusion-python-embed/src/dataframe.rs
+++ b/vegafusion-python-embed/src/dataframe.rs
@@ -527,7 +527,7 @@ fn expr_to_py(py: Python, expr: &Expr) -> Result<PyObject> {
     let proto_module = PyModule::import(py, "vegafusion.proto.datafusion_pb2")?;
     let logical_expr_class = proto_module.getattr("LogicalExprNode")?;
 
-    let proto_sort_expr = serialize_expr(&expr, &extension_codec)?;
+    let proto_sort_expr = serialize_expr(expr, &extension_codec)?;
 
     let sort_expr_bytes: Vec<u8> = proto_sort_expr.encode_to_vec();
 
diff --git a/vegafusion-runtime/tests/test_chart_state.rs b/vegafusion-runtime/tests/test_chart_state.rs
index 9059694f7..82ef107c1 100644
--- a/vegafusion-runtime/tests/test_chart_state.rs
+++ b/vegafusion-runtime/tests/test_chart_state.rs
@@ -1,3 +1,8 @@
+fn crate_dir() -> String {
+    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .display()
+        .to_string()
+}
 #[cfg(test)]
 mod tests {
     use crate::crate_dir;
@@ -138,9 +143,3 @@ mod tests {
         assert_eq!(response_updates, expected_updates)
     }
 }
-
-fn crate_dir() -> String {
-    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .display()
-        .to_string()
-}
diff --git a/vegafusion-runtime/tests/test_destringify_selection_datasets.rs b/vegafusion-runtime/tests/test_destringify_selection_datasets.rs
index 6fbcee054..5872cb657 100644
--- a/vegafusion-runtime/tests/test_destringify_selection_datasets.rs
+++ b/vegafusion-runtime/tests/test_destringify_selection_datasets.rs
@@ -1,3 +1,8 @@
+fn crate_dir() -> String {
+    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .display()
+        .to_string()
+}
 #[cfg(test)]
 mod tests {
     use crate::crate_dir;
@@ -60,9 +65,3 @@ mod tests {
         }
     }
 }
-
-fn crate_dir() -> String {
-    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .display()
-        .to_string()
-}
diff --git a/vegafusion-runtime/tests/test_pre_transform_extract.rs b/vegafusion-runtime/tests/test_pre_transform_extract.rs
index dcb811bc6..547dd0cdb 100644
--- a/vegafusion-runtime/tests/test_pre_transform_extract.rs
+++ b/vegafusion-runtime/tests/test_pre_transform_extract.rs
@@ -1,3 +1,8 @@
+fn crate_dir() -> String {
+    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .display()
+        .to_string()
+}
 #[cfg(test)]
 mod tests {
     use crate::crate_dir;
@@ -68,9 +73,3 @@ mod tests {
         );
     }
 }
-
-fn crate_dir() -> String {
-    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .display()
-        .to_string()
-}
diff --git a/vegafusion-runtime/tests/test_pre_transform_keep_variables.rs b/vegafusion-runtime/tests/test_pre_transform_keep_variables.rs
index 35e9be0d8..32e5330c9 100644
--- a/vegafusion-runtime/tests/test_pre_transform_keep_variables.rs
+++ b/vegafusion-runtime/tests/test_pre_transform_keep_variables.rs
@@ -1,3 +1,8 @@
+fn crate_dir() -> String {
+    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .display()
+        .to_string()
+}
 #[cfg(test)]
 mod tests {
     use crate::crate_dir;
@@ -68,7 +73,7 @@ mod tests {
         assert!(warnings.is_empty());
         assert_eq!(tx_spec.signals.len(), 1);
 
-        let signal0 = tx_spec.signals.get(0).unwrap();
+        let signal0 = tx_spec.signals.first().unwrap();
         assert_eq!(
             signal0.name,
             "layer_0_layer_0_bin_maxbins_10_IMDB_Rating_bins"
@@ -95,9 +100,3 @@ mod tests {
         }
     }
 }
-
-fn crate_dir() -> String {
-    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .display()
-        .to_string()
-}
diff --git a/vegafusion-runtime/tests/test_pre_transform_values.rs b/vegafusion-runtime/tests/test_pre_transform_values.rs
index 7de4f92c7..f9ffa6284 100644
--- a/vegafusion-runtime/tests/test_pre_transform_values.rs
+++ b/vegafusion-runtime/tests/test_pre_transform_values.rs
@@ -1,3 +1,18 @@
+fn crate_dir() -> String {
+    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .display()
+        .to_string()
+}
+
+fn setup_s3_environment_vars() {
+    unsafe {
+        std::env::set_var("AWS_DEFAULT_REGION", "us-east-1");
+        std::env::set_var("AWS_ACCESS_KEY_ID", "access_key123");
+        std::env::set_var("AWS_SECRET_ACCESS_KEY", "secret_key123");
+        std::env::set_var("AWS_ENDPOINT", "http://127.0.0.1:9000");
+        std::env::set_var("AWS_ALLOW_HTTP", "true");
+    }
+}
 #[cfg(test)]
 mod tests {
     use crate::{crate_dir, setup_s3_environment_vars};
@@ -421,17 +436,3 @@ mod tests {
         }
     }
 }
-
-fn crate_dir() -> String {
-    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .display()
-        .to_string()
-}
-
-fn setup_s3_environment_vars() {
-    std::env::set_var("AWS_DEFAULT_REGION", "us-east-1");
-    std::env::set_var("AWS_ACCESS_KEY_ID", "access_key123");
-    std::env::set_var("AWS_SECRET_ACCESS_KEY", "secret_key123");
-    std::env::set_var("AWS_ENDPOINT", "http://127.0.0.1:9000");
-    std::env::set_var("AWS_ALLOW_HTTP", "true");
-}
diff --git a/vegafusion-runtime/tests/test_projection_pushdown.rs b/vegafusion-runtime/tests/test_projection_pushdown.rs
index 96584e597..886cfa464 100644
--- a/vegafusion-runtime/tests/test_projection_pushdown.rs
+++ b/vegafusion-runtime/tests/test_projection_pushdown.rs
@@ -1,3 +1,8 @@
+fn crate_dir() -> String {
+    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .display()
+        .to_string()
+}
 #[cfg(test)]
 mod test_custom_specs {
     use crate::crate_dir;
@@ -53,9 +58,3 @@ mod test_custom_specs {
         }
     }
 }
-
-fn crate_dir() -> String {
-    std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .display()
-        .to_string()
-}
diff --git a/vegafusion-runtime/tests/util/check.rs b/vegafusion-runtime/tests/util/check.rs
index ad7a27800..84dab9388 100644
--- a/vegafusion-runtime/tests/util/check.rs
+++ b/vegafusion-runtime/tests/util/check.rs
@@ -131,7 +131,7 @@ pub fn eval_vegafusion_transforms(
         .unwrap();
     let result_signals = result_signals
         .into_iter()
-        .map(|v| v.as_scalar().map(|v| v.clone()))
+        .map(|v| v.as_scalar().cloned())
         .collect::<Result<Vec<ScalarValue>>>()
         .unwrap();
     (result_data, result_signals)