refactor(file_system): deduplicate read methods and use Vec<u8>

benches/memory_fs.rs

@@ -218,11 +218,10 @@ impl FileSystem for BenchMemoryFS {
         Self::default()
     }
 
-    fn read_to_string(&self, path: &Path) -> io::Result<String> {
+    fn read(&self, path: &Path) -> io::Result<Vec<u8>> {
         // Try direct lookup first
         if let Some(bytes) = self.files.get(path) {
-            return String::from_utf8(bytes.clone())
-                .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e));
+            return Ok(bytes.clone());
         }
 
         // Try following symlinks
@@ -241,14 +240,18 @@ impl FileSystem for BenchMemoryFS {
             };
 
             if let Some(bytes) = self.files.get(&current) {
-                return String::from_utf8(bytes.clone())
-                    .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e));
+                return Ok(bytes.clone());
             }
         }
 
         Err(io::Error::new(io::ErrorKind::NotFound, format!("File not found: {}", path.display())))
     }
 
+    fn read_to_string(&self, path: &Path) -> io::Result<String> {
+        let bytes = self.read(path)?;
+        String::from_utf8(bytes).map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
+    }
+
     fn metadata(&self, path: &Path) -> io::Result<FileMetadata> {
         // Check if it's a file (direct)
         if self.files.contains_key(path) {

benches/resolver.rs

@@ -371,7 +371,7 @@ fn bench_package_json_deserialization(c: &mut Criterion) {
     for (name, json) in data {
         group.bench_function(name, |b| {
             b.iter_with_setup_wrapper(|runner| {
-                let json = json.clone();
+                let json = json.clone().into_bytes();
                 runner.run(|| {
                     PackageJson::parse(&fs, test_path.clone(), test_realpath.clone(), json)
                         .expect("Failed to parse JSON");

src/cache/cache_impl.rs

@@ -109,9 +109,7 @@ impl<Fs: FileSystem> Cache<Fs> {
             .package_json
             .get_or_try_init(|| {
                 let package_json_path = path.path.join("package.json");
-                let Ok(package_json_string) =
-                    self.fs.read_to_string_bypass_system_cache(&package_json_path)
-                else {
+                let Ok(package_json_bytes) = self.fs.read(&package_json_path) else {
                     return Ok(None);
                 };
 
@@ -120,7 +118,7 @@ impl<Fs: FileSystem> Cache<Fs> {
                 } else {
                     package_json_path.clone()
                 };
-                PackageJson::parse(&self.fs, package_json_path, real_path, package_json_string)
+                PackageJson::parse(&self.fs, package_json_path, real_path, package_json_bytes)
                     .map(|package_json| Some(Arc::new(package_json)))
                     .map_err(ResolveError::Json)
             })
@@ -167,7 +165,7 @@ impl<Fs: FileSystem> Cache<Fs> {
         };
         let mut tsconfig_string = self
             .fs
-            .read_to_string_bypass_system_cache(&tsconfig_path)
+            .read_to_string(&tsconfig_path)
             .map_err(|_| ResolveError::TsconfigNotFound(path.to_path_buf()))?;
         let mut tsconfig =
             TsConfig::parse(root, &tsconfig_path, &mut tsconfig_string).map_err(|error| {

src/file_system.rs

@@ -17,29 +17,19 @@ pub trait FileSystem: Send + Sync {
     #[cfg(not(feature = "yarn_pnp"))]
     fn new() -> Self;
 
-    /// See [std::fs::read_to_string]
+    /// See [std::fs::read]
     ///
     /// # Errors
     ///
-    /// * See [std::fs::read_to_string]
-    /// ## Warning
-    /// Use `&Path` instead of a generic `P: AsRef<Path>` here,
-    /// because object safety requirements, it is especially useful, when
-    /// you want to store multiple `dyn FileSystem` in a `Vec` or use a `ResolverGeneric<Fs>` in
-    /// napi env.
-    fn read_to_string(&self, path: &Path) -> io::Result<String>;
+    /// * See [std::fs::read]
+    fn read(&self, path: &Path) -> io::Result<Vec<u8>>;
 
-    /// Reads a file while bypassing the system cache.
-    ///
-    /// This is useful in scenarios where the file content is already cached in memory
-    /// and you want to avoid the overhead of using the system cache.
+    /// See [std::fs::read_to_string]
     ///
     /// # Errors
     ///
     /// * See [std::fs::read_to_string]
-    fn read_to_string_bypass_system_cache(&self, path: &Path) -> io::Result<String> {
-        self.read_to_string(path)
-    }
+    fn read_to_string(&self, path: &Path) -> io::Result<String>;
 
     /// See [std::fs::metadata]
     ///
@@ -236,51 +226,26 @@ impl FileSystem for FileSystemOs {
         Self
     }
 
-    fn read_to_string(&self, path: &Path) -> io::Result<String> {
+    fn read(&self, path: &Path) -> io::Result<Vec<u8>> {
         cfg_if! {
             if #[cfg(feature = "yarn_pnp")] {
                 if self.yarn_pnp {
                     return match VPath::from(path)? {
                         VPath::Zip(info) => {
-                            self.pnp_lru.read_to_string(info.physical_base_path(), info.zip_path)
+                            self.pnp_lru.read(info.physical_base_path(), info.zip_path)
                         }
-                        VPath::Virtual(info) => Self::read_to_string(&info.physical_base_path()),
-                        VPath::Native(path) => Self::read_to_string(&path),
+                        VPath::Virtual(info) => fs::read(info.physical_base_path()),
+                        VPath::Native(path) => fs::read(path),
                     }
                 }
             }
         }
-        Self::read_to_string(path)
+        fs::read(path)
     }
 
-    #[allow(clippy::items_after_statements)]
-    fn read_to_string_bypass_system_cache(&self, path: &Path) -> io::Result<String> {
-        #[cfg(feature = "yarn_pnp")]
-        if self.yarn_pnp {
-            return match VPath::from(path)? {
-                VPath::Zip(info) => {
-                    self.pnp_lru.read_to_string(info.physical_base_path(), info.zip_path)
-                }
-                VPath::Virtual(info) => Self::read_to_string(&info.physical_base_path()),
-                VPath::Native(path) => Self::read_to_string(&path),
-            };
-        }
-
-        cfg_if! {
-            if #[cfg(target_os = "macos")] {
-                use std::io::Read;
-                let mut fd = fs::OpenOptions::new().read(true).open(path)?;
-                // Apply F_NOCACHE to bypass filesystem cache
-                rustix::fs::fcntl_nocache(&fd, true)?;
-                let meta = fd.metadata()?;
-                #[allow(clippy::cast_possible_truncation)]
-                let mut buffer = Vec::with_capacity(meta.len() as usize);
-                fd.read_to_end(&mut buffer)?;
-                Self::validate_string(buffer)
-            } else {
-                Self::read_to_string(path)
-            }
-        }
+    fn read_to_string(&self, path: &Path) -> io::Result<String> {
+        let bytes = self.read(path)?;
+        Self::validate_string(bytes)
     }
 
     fn metadata(&self, path: &Path) -> io::Result<FileMetadata> {

src/package_json/serde.rs

@@ -217,27 +217,23 @@ impl PackageJson {
         Ok(None)
     }
 
-    /// Parse a package.json file from JSON string
+    /// Parse a package.json file from JSON bytes
     ///
     /// # Errors
     pub fn parse<Fs: FileSystem>(
         _fs: &Fs,
         path: PathBuf,
         realpath: PathBuf,
-        json: String,
+        json: Vec<u8>,
     ) -> Result<Self, JSONError> {
-        // Strip BOM
-        let json_string = if json.starts_with('\u{FEFF}') {
-            json.trim_start_matches('\u{FEFF}')
-        } else {
-            json.as_str()
-        };
+        // Strip BOM - UTF-8 BOM is 3 bytes: 0xEF, 0xBB, 0xBF
+        let json_bytes = if json.starts_with(b"\xEF\xBB\xBF") { &json[3..] } else { &json[..] };
 
         // Check if empty after BOM stripping
-        super::check_if_empty(json_string.as_bytes(), path.clone())?;
+        super::check_if_empty(json_bytes, path.clone())?;
 
-        // Parse JSON
-        let value = serde_json::from_str::<Value>(json_string).map_err(|error| JSONError {
+        // Parse JSON directly from bytes
+        let value = serde_json::from_slice::<Value>(json_bytes).map_err(|error| JSONError {
             path: path.clone(),
             message: error.to_string(),
             line: error.line(),

src/package_json/simd.rs

@@ -250,18 +250,18 @@ impl PackageJson {
         Ok(None)
     }
 
-    /// Parse a package.json file from JSON string
+    /// Parse a package.json file from JSON bytes
     ///
     /// # Panics
     /// # Errors
     pub fn parse<Fs: FileSystem>(
         fs: &Fs,
         path: PathBuf,
         realpath: PathBuf,
-        json: String,
+        json: Vec<u8>,
     ) -> Result<Self, JSONError> {
         // Strip BOM in place by replacing with spaces (no reallocation)
-        let mut json_bytes = json.into_bytes();
+        let mut json_bytes = json;
         if json_bytes.starts_with(b"\xEF\xBB\xBF") {
             json_bytes[0] = b' ';
             json_bytes[1] = b' ';
@@ -281,15 +281,15 @@ impl PackageJson {
             // We re-read because simd_json may have mutated the buffer during its failed parse attempt
             // simd_json doesn't provide line/column info, so we use serde_json for better error messages
             let fallback_result = fs
-                .read_to_string(&realpath)
+                .read(&realpath)
                 .map_err(|io_error| JSONError {
                     path: path.clone(),
                     message: format!("Failed to re-read file for error reporting: {io_error}"),
                     line: 0,
                     column: 0,
                 })
-                .and_then(|content| {
-                    serde_json::from_str::<serde_json::Value>(&content).map_err(|serde_error| {
+                .and_then(|bytes| {
+                    serde_json::from_slice::<serde_json::Value>(&bytes).map_err(|serde_error| {
                         JSONError {
                             path: path.clone(),
                             message: serde_error.to_string(),

src/tests/memory_fs.rs

@@ -52,17 +52,22 @@ impl FileSystem for MemoryFS {
         Self::default()
     }
 
-    fn read_to_string(&self, path: &Path) -> io::Result<String> {
+    fn read(&self, path: &Path) -> io::Result<Vec<u8>> {
         use vfs::FileSystem;
         let mut file = self
             .fs
             .open_file(path.to_string_lossy().as_ref())
             .map_err(|err| io::Error::new(io::ErrorKind::NotFound, err))?;
-        let mut buffer = String::new();
-        file.read_to_string(&mut buffer).unwrap();
+        let mut buffer = Vec::new();
+        file.read_to_end(&mut buffer).unwrap();
         Ok(buffer)
     }
 
+    fn read_to_string(&self, path: &Path) -> io::Result<String> {
+        let bytes = self.read(path)?;
+        crate::FileSystemOs::validate_string(bytes)
+    }
+
     fn metadata(&self, path: &Path) -> io::Result<FileMetadata> {
         use vfs::FileSystem;
         let metadata = self