diff --git a/crates/diagnostics/src/local_tracing.rs b/crates/diagnostics/src/local_tracing.rs
index 3da11835b..f2848ffaa 100644
--- a/crates/diagnostics/src/local_tracing.rs
+++ b/crates/diagnostics/src/local_tracing.rs
@@ -6,43 +6,34 @@ use tracing_subscriber::{fmt::format::FmtSpan, EnvFilter, Layer};
 static IS_TRACING_ENABLED: AtomicBool = AtomicBool::new(false);
 
 pub fn enable_tracing_by_env() {
-    let trace_var = std::env::var("TRACE").ok();
-    let is_enable_tracing = trace_var.is_some();
+    let Ok(trace_var) = std::env::var("TRACE") else {
+        return
+    };
 
-    if is_enable_tracing && !IS_TRACING_ENABLED.swap(true, std::sync::atomic::Ordering::SeqCst) {
+    if !IS_TRACING_ENABLED.swap(true, std::sync::atomic::Ordering::SeqCst) {
         use tracing_subscriber::{fmt, prelude::*};
-        let layers = generate_common_layers(trace_var);
+        let layer = common_layer(&trace_var);
 
         tracing_subscriber::registry()
-            .with(layers)
+            .with(layer)
             .with(fmt::layer().pretty().with_file(true).with_span_events(FmtSpan::CLOSE))
             .init();
         tracing::trace!("enable_tracing_by_env");
     }
 }
 
-fn generate_common_layers(
-    trace_var: Option<String>,
-) -> Vec<Box<dyn Layer<tracing_subscriber::Registry> + Send + Sync>> {
-    let default_level = trace_var.as_ref().and_then(|var| Level::from_str(var).ok());
-
-    let mut layers = vec![];
-    if let Some(default_level) = default_level {
-        layers.push(
-            tracing_subscriber::filter::Targets::new()
-                .with_targets(vec![("pacquet_tarball", default_level)])
-                .boxed(),
-        );
+fn common_layer(trace_var: &str) -> Box<dyn Layer<tracing_subscriber::Registry> + Send + Sync> {
+    if let Ok(default_level) = Level::from_str(trace_var) {
+        tracing_subscriber::filter::Targets::new()
+            .with_target("pacquet_tarball", default_level)
+            .boxed()
     } else {
-        // SAFETY: we know that trace_var is `Ok(String)` now,
-        // for the second unwrap, if we can't parse the directive, then the tracing result would be
+        // SAFETY: for the `expect`, if we can't parse the directive, then the tracing result would be
         // unexpected, then panic is reasonable
-        let env_layer = EnvFilter::builder()
+        EnvFilter::builder()
             .with_regex(true)
-            .parse(trace_var.expect("Should not be empty"))
-            .expect("Parse tracing directive syntax failed,for details about the directive syntax you could refer https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#directives");
-
-        layers.push(env_layer.boxed());
+            .parse(trace_var)
+            .expect("Parse tracing directive syntax failed,for details about the directive syntax you could refer https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#directives")
+            .boxed()
     }
-    layers
 }
diff --git a/crates/package_json/src/lib.rs b/crates/package_json/src/lib.rs
index 3f3004f8f..f83f8c591 100644
--- a/crates/package_json/src/lib.rs
+++ b/crates/package_json/src/lib.rs
@@ -1,7 +1,6 @@
 use std::{
     collections::HashMap,
     convert::Into,
-    ffi::OsStr,
     fs,
     io::{Read, Write},
     path::PathBuf,
@@ -77,11 +76,11 @@ impl PackageJson {
 
     fn write_to_file(path: &PathBuf) -> Result<Value, PackageJsonError> {
         let mut file = fs::File::create(path)?;
-        let mut name = "";
-        if let Some(folder) = path.parent() {
-            // Set the default package name as the folder of the current directory
-            name = folder.file_name().unwrap_or(OsStr::new("")).to_str().unwrap();
-        }
+        let name = path
+            .parent()
+            .and_then(|folder| folder.file_name())
+            .and_then(|file_name| file_name.to_str())
+            .unwrap_or("");
         let package_json = json!({
             "name": name,
             "version": "1.0.0",