Add support for user provided closure to receive nonfatal errors

CHANGELOG.md

@@ -1,5 +1,11 @@
 # CHANGELOG
 
+## 7.0.0
+
+- Add support to `WhichConfig` for a user provided closure that will be called whenever a nonfatal error occurs.
+  This technically breaks a few APIs due to the need to add more generics and lifetimes. Most code will compile
+  without changes.
+
 ## 6.0.3
 
 - Enhance `tracing` feature with some `debug` level logs for higher level logic.

Cargo.toml

@@ -1,9 +1,9 @@
 [package]
 name = "which"
-version = "6.0.3"
+version = "7.0.0"
 edition = "2021"
 rust-version = "1.70"
-authors = ["Harry Fei <tiziyuanfang@gmail.com>"]
+authors = ["Harry Fei <tiziyuanfang@gmail.com>, Jacob Kiesel <jake@bitcrafters.co>"]
 repository = "https://github.com/harryfei/which-rs.git"
 documentation = "https://docs.rs/which/"
 license = "MIT"

src/checker.rs

@@ -1,4 +1,5 @@
 use crate::finder::Checker;
+use crate::{NonFatalError, NonFatalErrorHandler};
 use std::fs;
 use std::path::Path;
 
@@ -12,16 +13,32 @@ impl ExecutableChecker {
 
 impl Checker for ExecutableChecker {
     #[cfg(any(unix, target_os = "wasi", target_os = "redox"))]
-    fn is_valid(&self, path: &Path) -> bool {
+    fn is_valid<F: NonFatalErrorHandler>(
+        &self,
+        path: &Path,
+        nonfatal_error_handler: &mut F,
+    ) -> bool {
+        use std::io;
+
         use rustix::fs as rfs;
-        let ret = rfs::access(path, rfs::Access::EXEC_OK).is_ok();
+        let ret = rfs::access(path, rfs::Access::EXEC_OK)
+            .map_err(|e| {
+                nonfatal_error_handler.handle(NonFatalError::Io(io::Error::from_raw_os_error(
+                    e.raw_os_error(),
+                )))
+            })
+            .is_ok();
         #[cfg(feature = "tracing")]
         tracing::trace!("{} EXEC_OK = {ret}", path.display());
         ret
     }
 
     #[cfg(windows)]
-    fn is_valid(&self, _path: &Path) -> bool {
+    fn is_valid<F: NonFatalErrorHandler>(
+        &self,
+        _path: &Path,
+        _nonfatal_error_handler: &mut F,
+    ) -> bool {
         true
     }
 }
@@ -36,7 +53,11 @@ impl ExistedChecker {
 
 impl Checker for ExistedChecker {
     #[cfg(target_os = "windows")]
-    fn is_valid(&self, path: &Path) -> bool {
+    fn is_valid<F: NonFatalErrorHandler>(
+        &self,
+        path: &Path,
+        nonfatal_error_handler: &mut F,
+    ) -> bool {
         let ret = fs::symlink_metadata(path)
             .map(|metadata| {
                 let file_type = metadata.file_type();
@@ -49,8 +70,11 @@ impl Checker for ExistedChecker {
                 );
                 file_type.is_file() || file_type.is_symlink()
             })
+            .map_err(|e| {
+                nonfatal_error_handler.handle(NonFatalError::Io(e));
+            })
             .unwrap_or(false)
-            && (path.extension().is_some() || matches_arch(path));
+            && (path.extension().is_some() || matches_arch(path, nonfatal_error_handler));
         #[cfg(feature = "tracing")]
         tracing::trace!(
             "{} has_extension = {}, ExistedChecker::is_valid() = {ret}",
@@ -61,43 +85,63 @@ impl Checker for ExistedChecker {
     }
 
     #[cfg(not(target_os = "windows"))]
-    fn is_valid(&self, path: &Path) -> bool {
-        let ret = fs::metadata(path)
-            .map(|metadata| metadata.is_file())
-            .unwrap_or(false);
+    fn is_valid<F: NonFatalErrorHandler>(
+        &self,
+        path: &Path,
+        nonfatal_error_handler: &mut F,
+    ) -> bool {
+        let ret = fs::metadata(path).map(|metadata| metadata.is_file());
         #[cfg(feature = "tracing")]
-        tracing::trace!("{} is_file() = {ret}", path.display());
-        ret
+        tracing::trace!("{} is_file() = {ret:?}", path.display());
+        match ret {
+            Ok(ret) => ret,
+            Err(e) => {
+                nonfatal_error_handler.handle(NonFatalError::Io(e));
+                false
+            }
+        }
     }
 }
 
 #[cfg(target_os = "windows")]
-fn matches_arch(path: &Path) -> bool {
-    let ret = winsafe::GetBinaryType(&path.display().to_string()).is_ok();
+fn matches_arch<F: NonFatalErrorHandler>(path: &Path, nonfatal_error_handler: &mut F) -> bool {
+    use std::io;
+
+    let ret = winsafe::GetBinaryType(&path.display().to_string())
+        .map_err(|e| {
+            nonfatal_error_handler.handle(NonFatalError::Io(io::Error::from_raw_os_error(
+                e.raw() as i32
+            )))
+        })
+        .is_ok();
     #[cfg(feature = "tracing")]
     tracing::trace!("{} matches_arch() = {ret}", path.display());
     ret
 }
 
 pub struct CompositeChecker {
-    checkers: Vec<Box<dyn Checker>>,
+    existed_checker: ExistedChecker,
+    executable_checker: ExecutableChecker,
 }
 
 impl CompositeChecker {
     pub fn new() -> CompositeChecker {
         CompositeChecker {
-            checkers: Vec::new(),
+            executable_checker: ExecutableChecker::new(),
+            existed_checker: ExistedChecker::new(),
         }
     }
-
-    pub fn add_checker(mut self, checker: Box<dyn Checker>) -> CompositeChecker {
-        self.checkers.push(checker);
-        self
-    }
 }
 
 impl Checker for CompositeChecker {
-    fn is_valid(&self, path: &Path) -> bool {
-        self.checkers.iter().all(|checker| checker.is_valid(path))
+    fn is_valid<F: NonFatalErrorHandler>(
+        &self,
+        path: &Path,
+        nonfatal_error_handler: &mut F,
+    ) -> bool {
+        self.existed_checker.is_valid(path, nonfatal_error_handler)
+            && self
+                .executable_checker
+                .is_valid(path, nonfatal_error_handler)
     }
 }

src/error.rs

@@ -1,4 +1,4 @@
-use std::fmt;
+use std::{fmt, io};
 
 pub type Result<T> = std::result::Result<T, Error>;
 
@@ -26,3 +26,19 @@ impl fmt::Display for Error {
         }
     }
 }
+
+#[derive(Debug)]
+#[non_exhaustive]
+pub enum NonFatalError {
+    Io(io::Error),
+}
+
+impl std::error::Error for NonFatalError {}
+
+impl fmt::Display for NonFatalError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Io(e) => write!(f, "{e}"),
+        }
+    }
+}

src/finder.rs

@@ -1,7 +1,7 @@
 use crate::checker::CompositeChecker;
-use crate::error::*;
 #[cfg(windows)]
 use crate::helper::has_executable_extension;
+use crate::{error::*, NonFatalErrorHandler};
 use either::Either;
 #[cfg(feature = "regex")]
 use regex::Regex;
@@ -25,7 +25,11 @@ fn home_dir() -> Option<std::path::PathBuf> {
 }
 
 pub trait Checker {
-    fn is_valid(&self, path: &Path) -> bool;
+    fn is_valid<F: NonFatalErrorHandler>(
+        &self,
+        path: &Path,
+        nonfatal_error_handler: &mut F,
+    ) -> bool;
 }
 
 trait PathExt {
@@ -62,17 +66,18 @@ impl Finder {
         Finder
     }
 
-    pub fn find<T, U, V>(
+    pub fn find<'a, T, U, V, F: NonFatalErrorHandler + 'a>(
         &self,
         binary_name: T,
         paths: Option<U>,
         cwd: Option<V>,
         binary_checker: CompositeChecker,
-    ) -> Result<impl Iterator<Item = PathBuf>>
+        mut nonfatal_error_handler: F,
+    ) -> Result<impl Iterator<Item = PathBuf> + 'a>
     where
         T: AsRef<OsStr>,
         U: AsRef<OsStr>,
-        V: AsRef<Path>,
+        V: AsRef<Path> + 'a,
     {
         let path = PathBuf::from(&binary_name);
 
@@ -92,39 +97,40 @@ impl Finder {
                     path.display()
                 );
                 // Search binary in cwd if the path have a path separator.
-                Either::Left(Self::cwd_search_candidates(path, cwd).into_iter())
+                Either::Left(Self::cwd_search_candidates(path, cwd))
             }
             _ => {
                 #[cfg(feature = "tracing")]
                 tracing::trace!("{} has no path seperators, so only paths in PATH environment variable will be searched.", path.display());
                 // Search binary in PATHs(defined in environment variable).
-                let paths =
-                    env::split_paths(&paths.ok_or(Error::CannotGetCurrentDirAndPathListEmpty)?)
-                        .collect::<Vec<_>>();
+                let paths = paths.ok_or(Error::CannotGetCurrentDirAndPathListEmpty)?;
+                let paths = env::split_paths(&paths).collect::<Vec<_>>();
                 if paths.is_empty() {
                     return Err(Error::CannotGetCurrentDirAndPathListEmpty);
                 }
 
-                Either::Right(Self::path_search_candidates(path, paths).into_iter())
+                Either::Right(Self::path_search_candidates(path, paths))
             }
         };
-        let ret = binary_path_candidates
-            .filter(move |p| binary_checker.is_valid(p))
-            .map(correct_casing);
+        let ret = binary_path_candidates.into_iter().filter_map(move |p| {
+            binary_checker
+                .is_valid(&p, &mut nonfatal_error_handler)
+                .then(|| correct_casing(p, &mut nonfatal_error_handler))
+        });
         #[cfg(feature = "tracing")]
-        let ret = ret.map(|p| {
+        let ret = ret.inspect(|p| {
             tracing::debug!("found path {}", p.display());
-            p
         });
         Ok(ret)
     }
 
     #[cfg(feature = "regex")]
-    pub fn find_re<T>(
+    pub fn find_re<T, F: NonFatalErrorHandler>(
         &self,
         binary_regex: impl Borrow<Regex>,
         paths: Option<T>,
         binary_checker: CompositeChecker,
+        mut nonfatal_error_handler: F,
     ) -> Result<impl Iterator<Item = PathBuf>>
     where
         T: AsRef<OsStr>,
@@ -148,7 +154,7 @@ impl Finder {
                     false
                 }
             })
-            .filter(move |p| binary_checker.is_valid(p));
+            .filter(move |p| binary_checker.is_valid(p, &mut nonfatal_error_handler));
 
         Ok(matching_re)
     }
@@ -277,14 +283,24 @@ fn tilde_expansion(p: &PathBuf) -> Cow<'_, PathBuf> {
 }
 
 #[cfg(target_os = "windows")]
-fn correct_casing(mut p: PathBuf) -> PathBuf {
+fn correct_casing<F: NonFatalErrorHandler>(
+    mut p: PathBuf,
+    nonfatal_error_handler: &mut F,
+) -> PathBuf {
     if let (Some(parent), Some(file_name)) = (p.parent(), p.file_name()) {
         if let Ok(iter) = fs::read_dir(parent) {
-            for e in iter.filter_map(std::result::Result::ok) {
-                if e.file_name().eq_ignore_ascii_case(file_name) {
-                    p.pop();
-                    p.push(e.file_name());
-                    break;
+            for e in iter {
+                match e {
+                    Ok(e) => {
+                        if e.file_name().eq_ignore_ascii_case(file_name) {
+                            p.pop();
+                            p.push(e.file_name());
+                            break;
+                        }
+                    }
+                    Err(e) => {
+                        nonfatal_error_handler.handle(NonFatalError::Io(e));
+                    }
                 }
             }
         }
@@ -293,6 +309,6 @@ fn correct_casing(mut p: PathBuf) -> PathBuf {
 }
 
 #[cfg(not(target_os = "windows"))]
-fn correct_casing(p: PathBuf) -> PathBuf {
+fn correct_casing<F: NonFatalErrorHandler>(p: PathBuf, _nonfatal_error_handler: &mut F) -> PathBuf {
     p
 }