From 8d160e34728eeb5eae87f6927f2d47bbc287cd9c Mon Sep 17 00:00:00 2001
From: Paul Campbell <pcampbell@kemitix.net>
Date: Sun, 3 Nov 2024 20:29:08 +0000
Subject: [PATCH] feat(fs): add .path(path).read_link()

---
 src/fs/mod.rs  |  2 +-
 src/fs/path.rs |  7 +++++++
 tests/fs.rs    | 36 ++++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/src/fs/mod.rs b/src/fs/mod.rs
index 1332eb4..1a8c9a8 100644
--- a/src/fs/mod.rs
+++ b/src/fs/mod.rs
@@ -46,7 +46,7 @@
 //! - [x] `std::fs::metadata` - `fs.path(path).metadata()` - Given a path, query the file system to get information about a file, directory, etc.
 //! - [x] `std::fs::read` - `fs.file(path).reader().bytes()` - Read the entire contents of a file into a bytes vector.
 //! - [x] `std::fs::read_dir` - `fs.dir(path).read()` - Returns an iterator over the entries within a directory.
-//! - [ ] `std::fs::read_link` - `link(path).read()` - Reads a symbolic link, returning the file that the link points to.
+//! - [x] `std::fs::read_link` - `fs.path(path).read_link()` - Reads a symbolic link, returning the file that the link points to.
 //! - [x] `std::fs::read_to_string` - `fs.file(path).reader().to_string()` - Read the entire contents of a file into a string.
 //! - [x] `std::fs::remove_dir` - `fs.dir(path).remove()` - Removes an empty directory.
 //! - [x] `std::fs::remove_dir_all` - `fs.dir(path).remove_all()` - Removes a directory at this path, after removing all its contents. Use carefully!
diff --git a/src/fs/path.rs b/src/fs/path.rs
index d5ab92e..50c99b5 100644
--- a/src/fs/path.rs
+++ b/src/fs/path.rs
@@ -344,6 +344,13 @@ impl<T: PathType> PathReal<T> {
         self.check_error()?;
         std::fs::set_permissions(self.as_pathbuf(), perms).map_err(Error::Io)
     }
+
+    pub fn read_link(&self) -> Result<PathReal<PathMarker>> {
+        self.check_error()?;
+        let read_path = std::fs::read_link(self.as_pathbuf()).map_err(Error::Io)?;
+        let path = read_path.strip_prefix(&self.base).unwrap().to_path_buf();
+        Ok(PathReal::new(&self.base, &path))
+    }
 }
 impl From<PathHandle<PathMarker>> for PathBuf {
     fn from(path: PathReal<PathMarker>) -> Self {
diff --git a/tests/fs.rs b/tests/fs.rs
index 11c7a57..925c7fe 100644
--- a/tests/fs.rs
+++ b/tests/fs.rs
@@ -32,6 +32,42 @@ mod path {
             Ok(())
         }
     }
+    mod read_link {
+        use super::*;
+
+        #[test]
+        fn should_read_link() -> TestResult {
+            let fs = fs::temp().expect("temp fs");
+
+            let file_path = fs.base().join("foo");
+            let file = fs.file(&file_path);
+            file.write("bar").expect("write");
+
+            let link_path = fs.base().join("bar");
+            let link = fs.path(&link_path);
+            file.soft_link(&link).expect("soft_link");
+
+            let read_link = link.read_link().expect("read_link");
+            assert_eq!(read_link.as_pathbuf(), file_path);
+
+            Ok(())
+        }
+
+        #[test]
+        fn should_fail_on_path_traversal() -> TestResult {
+            let fs = fs::temp().expect("temp fs");
+            let path = fs.base().join("..").join("foo");
+            let_assert!(
+                Err(fs::Error::PathTraversal {
+                    base: _base,
+                    path: _path
+                }) = fs.path(&path).read_link()
+            );
+
+            Ok(())
+        }
+    }
+
     mod metadata {
         use super::*;