deduplicate ToNormalPathComponent logic

Author: Byron

gix-fs/src/stack.rs

@@ -5,14 +5,14 @@ use std::path::{Component, Path, PathBuf};
 
 ///
 pub mod to_normal_path_components {
-    use std::ffi::OsString;
+    use std::path::PathBuf;
 
     /// The error used in [`ToNormalPathComponents::to_normal_path_components()`](super::ToNormalPathComponents::to_normal_path_components()).
     #[derive(Debug, thiserror::Error)]
     #[allow(missing_docs)]
     pub enum Error {
-        #[error("Input path \"{path}\" contains relative or absolute components", path = std::path::Path::new(.0.as_os_str()).display())]
-        NotANormalComponent(OsString),
+        #[error("Input path \"{path}\" contains relative or absolute components", path = .0.display())]
+        NotANormalComponent(PathBuf),
         #[error("Could not convert to UTF8 or from UTF8 due to ill-formed input")]
         IllegalUtf8,
     }
@@ -26,54 +26,54 @@ pub trait ToNormalPathComponents {
 
 impl ToNormalPathComponents for &Path {
     fn to_normal_path_components(&self) -> impl Iterator<Item = Result<&OsStr, to_normal_path_components::Error>> {
-        self.components().map(|component| match component {
-            Component::Normal(os_str) => Ok(os_str),
-            _ => Err(to_normal_path_components::Error::NotANormalComponent(
-                self.as_os_str().to_owned(),
-            )),
-        })
+        self.components().map(|c| component_to_os_str(c, self))
     }
 }
 
 impl ToNormalPathComponents for PathBuf {
     fn to_normal_path_components(&self) -> impl Iterator<Item = Result<&OsStr, to_normal_path_components::Error>> {
-        self.components().map(|component| match component {
-            Component::Normal(os_str) => Ok(os_str),
-            _ => Err(to_normal_path_components::Error::NotANormalComponent(
-                self.as_os_str().to_owned(),
-            )),
-        })
+        self.components().map(|c| component_to_os_str(c, self))
+    }
+}
+
+fn component_to_os_str<'a>(
+    component: Component<'a>,
+    path_with_component: &Path,
+) -> Result<&'a OsStr, to_normal_path_components::Error> {
+    match component {
+        Component::Normal(os_str) => Ok(os_str),
+        _ => Err(to_normal_path_components::Error::NotANormalComponent(
+            path_with_component.to_owned(),
+        )),
     }
 }
 
 impl ToNormalPathComponents for &BStr {
     fn to_normal_path_components(&self) -> impl Iterator<Item = Result<&OsStr, to_normal_path_components::Error>> {
-        self.split(|b| *b == b'/').filter(|c| !c.is_empty()).map(|component| {
-            gix_path::try_from_byte_slice(component.as_bstr())
-                .map_err(|_| to_normal_path_components::Error::IllegalUtf8)
-                .map(Path::as_os_str)
-        })
+        self.split(|b| *b == b'/').filter_map(bytes_component_to_os_str)
     }
 }
 
 impl ToNormalPathComponents for &str {
     fn to_normal_path_components(&self) -> impl Iterator<Item = Result<&OsStr, to_normal_path_components::Error>> {
-        self.split('/').filter(|c| !c.is_empty()).map(|component| {
-            gix_path::try_from_byte_slice(component.as_bytes())
-                .map_err(|_| to_normal_path_components::Error::IllegalUtf8)
-                .map(Path::as_os_str)
-        })
+        self.split('/').filter_map(|c| bytes_component_to_os_str(c.as_bytes()))
     }
 }
 
 impl ToNormalPathComponents for &BString {
     fn to_normal_path_components(&self) -> impl Iterator<Item = Result<&OsStr, to_normal_path_components::Error>> {
-        self.split(|b| *b == b'/').filter(|c| !c.is_empty()).map(|component| {
-            gix_path::try_from_byte_slice(component.as_bstr())
-                .map_err(|_| to_normal_path_components::Error::IllegalUtf8)
-                .map(Path::as_os_str)
-        })
+        self.split(|b| *b == b'/').filter_map(bytes_component_to_os_str)
+    }
+}
+
+fn bytes_component_to_os_str(component: &[u8]) -> Option<Result<&OsStr, to_normal_path_components::Error>> {
+    if component.is_empty() {
+        return None;
     }
+    gix_path::try_from_byte_slice(component.as_bstr())
+        .map_err(|_| to_normal_path_components::Error::IllegalUtf8)
+        .map(Path::as_os_str)
+        .into()
 }
 
 /// Access