Crate testdir

Semi-persistent, scoped test directories

This module provides a convenient way to have an empty directory for tests which can be inspected after the test run in a predicatable location. On subsequent test runs the directory trees of previous runs will be cleaned up to keep the total number of directories limited.

Quickstart

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_nonexisting() {
        let dir: PathBuf = testdir!();
        let path = dir.join("not-here.txt");
        assert!(!path.exists());
    }
}

If it does not yet exist this will create a directory called rstest-of-$USER in you system's temporary directory. Inside there you will find subdirectories named after your crate name and with a number suffix which increases each time your run the tests. There is also a -current suffix which symlinks to the most recent numbered directory.

Inside the numbered directory you will find a directory structure resembling your crate's modules structure. For example if the above tests are in lib.rs of a crate called mycrate, than on my UNIX system it looks like this:

$ tree /tmp/rstest-of-flub/
/tmp/rstest-of-flub/
+- mycrate-0/
|    +- mycrate/
|         +- tests/
|              +- test_nonexisting/
|              +- test_write/
|                   +- hello.txt
+- testdir-current -> /tmp/rstest-of-flub/mycrate-0

Doc tests and Integration tests

In order to re-use the same numbered test directories across testdir macro invocations we need to have somewhere to keep global state. This is currently stored in a process-wide global. However Cargo builds multiple test binaries in many situations, typically a project will have the main crate test binary, one for each integration test and one for each doctest. The current implementation means each will get its own numbered directory and the -current link will only point to the last one. This could be problematic if you have more test binaries than the number of numbered directories kept by the testdir macro. If you hit this limit a simple work-around is to limit the test binaries you invoke if you need to inspect one of the tests.

This should hopefully be fixed in the next version.

Macros

testdir

Structs

NumberedDir
TestDir

Constants

KEEP_DEFAULT

The number of test directories retained by the testdir macro.

Functions

with_global_testdir