1 files changed, 115 insertions, 0 deletions
diff --git a/src/scoped_path.rs b/src/scoped_path.rs
new file mode 100644
index 0000000..22d0ad9
--- /dev/null
+++ b/src/scoped_path.rs
@@ -0,0 +1,115 @@
+// Copyright 2020 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+use std::env::{current_exe, temp_dir};
+use std::fs::{create_dir_all, remove_dir_all};
+use std::ops::Deref;
+use std::path::{Path, PathBuf};
+use std::thread::panicking;
+
+use super::linux::{getpid, gettid};
+
+/// Returns a stable path based on the label, pid, and tid. If the label isn't provided the
+/// current_exe is used instead.
+pub fn get_temp_path(label: Option<&str>) -> PathBuf {
+    if let Some(label) = label {
+        temp_dir().join(format!("{}-{}-{}", label, getpid(), gettid()))
+    } else {
+        get_temp_path(Some(current_exe().unwrap().to_str().unwrap()))
+    }
+}
+
+/// Automatically deletes the path it contains when it goes out of scope unless it is a test and
+/// drop is called after a panic!.
+///
+/// This is particularly useful for creating temporary directories for use with tests.
+pub struct ScopedPath<P: AsRef<Path>>(P);
+
+impl<P: AsRef<Path>> ScopedPath<P> {
+    pub fn create(p: P) -> Result<Self, std::io::Error> {
+        create_dir_all(p.as_ref())?;
+        Ok(ScopedPath(p))
+    }
+}
+
+impl<P: AsRef<Path>> AsRef<Path> for ScopedPath<P> {
+    fn as_ref(&self) -> &Path {
+        self.0.as_ref()
+    }
+}
+
+impl<P: AsRef<Path>> Deref for ScopedPath<P> {
+    type Target = Path;
+
+    fn deref(&self) -> &Self::Target {
+        self.0.as_ref()
+    }
+}
+
+impl<P: AsRef<Path>> Drop for ScopedPath<P> {
+    fn drop(&mut self) {
+        // Leave the files on a failed test run for debugging.
+        if panicking() && cfg!(test) {
+            eprintln!("NOTE: Not removing {}", self.display());
+            return;
+        }
+        if let Err(e) = remove_dir_all(&**self) {
+            eprintln!("Failed to remove {}: {}", self.display(), e);
+        }
+    }
+}
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use super::*;
+
+    use std::panic::catch_unwind;
+
+    #[test]
+    fn gettemppath() {
+        assert_ne!("", get_temp_path(None).to_string_lossy());
+        assert_eq!(
+            get_temp_path(None),
+            get_temp_path(Some(current_exe().unwrap().to_str().unwrap()))
+        );
+        assert_ne!(
+            get_temp_path(Some("label")),
+            get_temp_path(Some(current_exe().unwrap().to_str().unwrap()))
+        );
+    }
+
+    #[test]
+    fn scopedpath_exists() {
+        let tmp_path = get_temp_path(None);
+        {
+            let scoped_path = ScopedPath::create(&tmp_path).unwrap();
+            assert!(scoped_path.exists());
+        }
+        assert!(!tmp_path.exists());
+    }
+
+    #[test]
+    fn scopedpath_notexists() {
+        let tmp_path = get_temp_path(None);
+        {
+            let _scoped_path = ScopedPath(&tmp_path);
+        }
+        assert!(!tmp_path.exists());
+    }
+
+    #[test]
+    fn scopedpath_panic() {
+        let tmp_path = get_temp_path(None);
+        assert!(catch_unwind(|| {
+            {
+                let scoped_path = ScopedPath::create(&tmp_path).unwrap();
+                assert!(scoped_path.exists());
+                panic!()
+            }
+        })
+        .is_err());
+        assert!(tmp_path.exists());
+        remove_dir_all(&tmp_path).unwrap();
+    }
+}