Add TempDir and NewLogFile test utilities

[belimawr]

What does this PR do?

This PR adds two helpers for tests:

• fs.TempDir creates a temporary folder that is kept when tests fails.
• NewLogFile creates a file that can be used as output for a logger or a a process. Methods to search strings in the file are also provided

Why is it important?

It helps us to keep temporary files and logs generated by tests when the test fails for easier debugging.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works

## Author's Checklist
## Related issues

[leehinman]

I'm not a fan of copying so much of the code that exists in t.TempDir(). Can we use t.TempDir and then just have the cleanup function copy or archive the contents in the case of a failure?

[belimawr]

Personally I like that the temp dir is already created on its final destination, so no matter how wrong the test goes, the files are kept.

Copying/archiving the temp dir after a test failure adds another point of failure and complexity that I'd like to avoid.

I'm not a fan of copying so much of the code that exists in t.TempDir()

I haven't copied much of it, well, the bit I copied was only the part sanitising the test name to create the folder.

[AndersonQ]

Personally I like that the temp dir is already created on its final destination, so no matter how wrong the test goes, the files are kept.

Copying/archiving the temp dir after a test failure adds another point of failure and complexity that I'd like to avoid.

I agree, it makes sense

[leehinman]

This isn't a blocker.

but I strongly suggest implementing "removeAll" like the stdlib testing library does. https://cs.opensource.google/go/go/+/refs/tags/go1.25.5:src/testing/testing.go;l=1392-1420

Windows lock files are not released immediately, so even if the code is correct and has released the lock, it can be milliseconds before you can delete the file.

And things like this are why I'm not in favor of reimplementing something that has been thoroughly tested, with lots of edge cases. Especially when it is under active maintenance.

[belimawr]

That's an interesting edge case. I can open a follow up PR to implement something like that. Or maybe even do the moving archiving logic. This can be implemented without breaking the API/behaviour.

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: f7d1755

History

• 💚 Build #899 succeeded 92b0da2
• 💔 Build #898 failed f7b2d26
• 💚 Build #897 succeeded 6657a87

cc @belimawr

[belimawr]

@leehinman @kruskall did you folks have a chance to see my replies to your comments?