Provide a way to generate shorter tempdir paths

[wiktor-k]

Hi,

I wanted to use tempdir to generate a Unix socket path for tests and just found out that they have stricter length limits than regular file names (108 on linux).

An excerpt from my logs:

Starting server on 127.0.0.1:41661; agent on "/home/wiktor/tmp/cargo/testdir-20/ssh_roundtrip/start_ssh_server_connect_and_check_result_of_signing/agent.sock"
...
thread 'start_ssh_server_connect_and_check_result_of_signing' panicked at signstar-request-signature/tests/ssh-roundtrip.rs:181:40:
error: std::io::error::Error - path must be shorter than SUN_LEN

("/home/wiktor/tmp/cargo/testdir-20/ssh_roundtrip/start_ssh_server_connect_and_check_result_of_signing/agent.sock" has 111 characters).

A workaround is to use shorter test names but sadly the path to the temp file varies between my local computer and the CI and this kind of workaround is basically a bomb that may go off any time.

It'd be good to be able to generate shorter, but still unique, paths with testdir.

Thanks!

[flub]

Another workaround could be to make the prefix shorter: if you look at the init_testdir! macro you can see it initialises a pub global testdir::TESTDIR using the NumberedDirbuilder. If you initialise this global before calling any macro you can customise the directory.

You could take this even a step further and build your own macro.

The main question I have for this feature is: how would you make it shorter while still being able to find the directory afterwards. I guess the directory usually gets printed so in theory you could go for directories without any nesting and just a, b, ..., aa etc. Is that what you have in mind?

[wiktor-k]

The main question I have for this feature is: how would you make it shorter while still being able to find the directory afterwards. I guess the directory usually gets printed so in theory you could go for directories without any nesting and just a, b, ..., aa etc. Is that what you have in mind?

Yep, something like this would work. Of course I understand the automatic generation of nice-names is a central feature of testdir so I feel kind of bad asking for short names but there's a use-case behind my feature request 😅

Thanks for the workarounds, I'll try them out!