Semi-persistent, scoped test directories

This crate aims to make it easier to use temporary directories in tests, primarily by calling the testdir!() macro somewhere in a test function. The direcetories are structured per-scope and per-test and will be available for inspection after the test has finished. On subsequent test runs older generations of test directories will be cleaned up.

If you've ever used pytest's tmp_path or tmpdir fixtures this pattern should be similar.

By default test directories are created as:

/tmp/rstest-of-$USER/$cargo_pkg_name-$N/module/path/test_name

Here $N is an integer generation number increasing with each cargo test invocation. Generations older than the 8 most recent ones are removed on the next cargo test run. Naturally /tmp is actually provided by std::env::temp_dir and $USER is also cross platform using the whoami crate.

There is also a symlink pointing to the most recent generation:

/tmp/rstest-of-$USER/$cargo_pkg_name-current -> $cargo_pkg_name_$N`

Example

Even when executing this with cargo test --jobs=1 these tests will pass as each gets their own unique directory:

// E.g. in lib.rs

mod tests {
    use std::path::PathBuf;
    use testdir::testdir;

    #[test]
    fn test_write() {
        let dir: PathBuf = testdir!();
        let path = dir.join("hello.txt");
        std::fs::write(&path, "hi there").ok();
        assert!(path.exists());
    }
    
    #[test]
    fn test_read() {
        let dir: PathBuf = testdir!();
        let path = dir.join("hello.txt");
        assert!(!path.exists());
    }
}

Afterwards you can inspect the directories and they should look something like this:

$ tree /tmp/rstest-of-flub/
/tmp/rstest-of-flub/
+- cargo-pkg-name-0
|    +- cratename
|         +- tests
|              +- test_read
|              +- test_write
|                   +- hello.txt
+- testdir-current -> /tmp/rstest-of-flub/cargo-pkg-name-0

Feedback and contributing

The code lives in a mercurial repository at https://hg.sr.ht/~/flub/testdir from which you can clone the repository.

For any feedback, bug reports or patches please send an email to ~flub/testdir@lists.sr.ht (or use u.flub.testdir@lists.sr.ht if your mail client does not accept the former).

The mailing list archive can be browsed at https://lists.sr.ht/~flub/testdir.