1 files changed, 68 insertions, 0 deletions
diff --git a/third_party/rust/tempfile/tests/tempfile.rs b/third_party/rust/tempfile/tests/tempfile.rs
new file mode 100644
index 0000000000..c2f684438d
--- /dev/null
+++ b/third_party/rust/tempfile/tests/tempfile.rs
@@ -0,0 +1,68 @@
+#![deny(rust_2018_idioms)]
+
+use std::fs;
+use std::io::{Read, Seek, SeekFrom, Write};
+#[cfg(target_os = "linux")]
+use std::{
+    sync::mpsc::{sync_channel, TryRecvError},
+    thread,
+};
+
+#[test]
+fn test_basic() {
+    let mut tmpfile = tempfile::tempfile().unwrap();
+    write!(tmpfile, "abcde").unwrap();
+    tmpfile.seek(SeekFrom::Start(0)).unwrap();
+    let mut buf = String::new();
+    tmpfile.read_to_string(&mut buf).unwrap();
+    assert_eq!("abcde", buf);
+}
+
+#[test]
+fn test_cleanup() {
+    let tmpdir = tempfile::tempdir().unwrap();
+    {
+        let mut tmpfile = tempfile::tempfile_in(&tmpdir).unwrap();
+        write!(tmpfile, "abcde").unwrap();
+    }
+    let num_files = fs::read_dir(&tmpdir).unwrap().count();
+    assert!(num_files == 0);
+}
+
+// Only run this test on Linux. MacOS doesn't like us creating so many files, apparently.
+#[cfg(target_os = "linux")]
+#[test]
+fn test_pathological_cleaner() {
+    let tmpdir = tempfile::tempdir().unwrap();
+    let (tx, rx) = sync_channel(0);
+    let cleaner_thread = thread::spawn(move || {
+        let tmp_path = rx.recv().unwrap();
+        while rx.try_recv() == Err(TryRecvError::Empty) {
+            let files = fs::read_dir(&tmp_path).unwrap();
+            for f in files {
+                // skip errors
+                if f.is_err() {
+                    continue;
+                }
+                let f = f.unwrap();
+                let _ = fs::remove_file(f.path());
+            }
+        }
+    });
+
+    // block until cleaner_thread makes progress
+    tx.send(tmpdir.path().to_owned()).unwrap();
+    // need 40-400 iterations to encounter race with cleaner on original system
+    for _ in 0..10000 {
+        let mut tmpfile = tempfile::tempfile_in(&tmpdir).unwrap();
+        write!(tmpfile, "abcde").unwrap();
+        tmpfile.seek(SeekFrom::Start(0)).unwrap();
+        let mut buf = String::new();
+        tmpfile.read_to_string(&mut buf).unwrap();
+        assert_eq!("abcde", buf);
+    }
+
+    // close the channel to make cleaner_thread exit
+    drop(tx);
+    cleaner_thread.join().expect("The cleaner thread failed");
+}