Support setting environmental variables for the test runner

[JohnSpeno]

In the microsoft-python discord, I asked:

Is there a way to have the DYLD_LIBRARY_PATH environmental variable set for the built-in test discovery/runner? I set it up for debugging + debugging tests via launch.json but that isn't integrated with the testing UI which is what I hope to use. This is on macOS 11.4 (big sur) with vscode Version: 1.58.2 and all extensions up to date. Thanks. Note: launching using code . in a shell with the env set properly apparently doesn't propagate DYLD_LIBRARY_PATH as a macOS safety feature these days.

And Brett Cannon said:

There currently isn't, but if you could open a feature request at https://github.com/microsoft/vscode-python that would be appreciated!

so I am doing that.

I find getting environmental variables set for various parts of VS Code to be difficult currently. I can work around that by running code . in my pre-configured shell environment to launch vscode on my project and it mostly works. The DYLD_LIBRARY_PATH might be a special case due to hardened runtimes on macOS but I'm not exactly sure.

Thanks.

[1st]

My question was asked here: #16773

Without ENV VARS it's impossible to use test runner, and no way to run tests using UI. Waiting for the feature.

@JohnSpeno Will wait for the implementation. Shouldn't be a hard to do. Thank you for the opening Feature Request!

[JohnSpeno]

I have not created a bug report, and I thought this issue was the feature request.

[brettcannon]

This discussion is the feature request.

[1st]

Ok, good. How can we push this feature to be implemented faster? @brettcannon

It seems an easy thing:

• add new argument to the settings for the test discovery runner
• when test discovery is running, use the defined list of ENV variables

If you can point me to a file where the test runner is running, I can hardcore the needed me variables and will validate that it works. Then the proper implementation may be added to the following release.

Hope that this feature will be done soon to be able to use tests.

Or, alternatively, maybe I can run the test discovery manually and will define needed env variables for it. But how VS Code will recognize it? If it stores some file with list of discovered tests, then manual run n help

[brettcannon]

Upvoting this discussion is how to potentially get it faster.

It seems an easy thing

I know you don't mean anything by this comment, but do know that phrasing things as "it seems easy" can bit a bit off-putting to project maintainers as it feels like you're dismissing the hidden difficulty and costs of the project (i.e. "it's easy so why don't you just do it"?). For instance, "add new argument to the settings for the test discovery runner" includes testing, how that affects pytest and unittest, etc. "when test discovery is running, use the defined list of ENV variables", doesn't cover where those environment variables are defined, text execution, whether those need to somehow be different, etc. Plumbing people's environment details throughout the extension is surprisingly messy and a big problem to solve. Plus we have lots of other things on our plate as you're not the only person asking for something. 😉

If you can point me to a file where the test runner is running

https://github.com/microsoft/vscode-python/tree/main/src/client/testing is where all the testing code resides, but we are planning to rewrite the test discovery and execution code shortly (this very likely won't cover this, though, as this is part of a wider issue of how to get environment variables everywhere we run Python code for the user, not just testing).

maybe I can run the test discovery manually and will define needed env variables for it. But how VS Code will recognize it? If it stores some file with list of discovered tests, then manual run n help

Nothing stored on disk; it's all dynamically found and directly fed into the (soon to be released) test provider that VS Code has.

[brettcannon]

Moved to #17171