Run test cases for nargo test in parallel

[TomAFrench]

Problem

We're getting some complaints in the discord that nargo test is running slow.

Happy Case

We can get some easy speed-up by running multiple tests in parallel to take advantage of additional cores.

Alternatives Considered

No response

Additional Context

No response

Would you like to submit a PR for this Issue?

No

Support Needs

No response

[skaunov]

I would take on this! Could you outline at least something to start with? (Indicate primary moving parts, and do you have on your mind something more than rayon, std::thread, and maybe crossbeam?)

[jfecher]

@skaunov I'd look into the integration tests in crates/nargo_cli/tests/test_data. There are wrappers generated to run these automatically, see crates/nargo_cli/tests/execute.rs. As for a threading lib, I'd suggest using either std::thread or rayon as a test dependency.

[skaunov]

I spent some time getting to know Nix, Cargo build, and tests template system (which seems quite exotic, though it could be lack of my experience as well). X)

Will be looking for nargo test usage in dirs which used to be <test_data> to follow the cases and add parallelization to nargo test itself.

Btw, I currently restricted to remote dev environment (with vscode-server usually) and it doesn't look like something seamless to run with Nix. So I went with Gitpod, which solves this [quite ok]; so now I either finish the thing in 50 computing hours, either will need some alternatives (any hints to this technicality are welcome!).

[quite ok]: starting the environment takes double-digit number of minutes, but at least it's reliable

[skaunov]

After reading through <build.rs> with all aforementioned in mind I got confused pretty quickly. @TomAFrench stated the issue that nargo test invocation needs to be parallelized, but starting from this end I don't see any nargo test invocations at all --- only testing nargo compilation and execution features. =(

Maybe I'll try just to unwind <nargo_cli> to find some relevant places to begin with. Though it would be really helpful if somebody could point out to me what am I missing or any alternative entry point for the issue.

Also a side question. Is it possible to locate this resulting file with the tests that <build.rs> produce? Locating binaries of these tests was easy, but what's the lifecycle of that code it stitches from the templates?

@jfecher

[TomAFrench]

Hey, I don't think that looking into the integration test suite is useful for this task.

This issue is to modify the nargo test command so that test cases are run in parallel. We don't need to interact with the integration test suite for nargo itself for this.

Also a side question. Is it possible to locate this resulting file with the tests that <build.rs> produce? Locating binaries of these tests was easy, but what's the lifecycle of that code it stitches from the templates?

This file isn't relevant for this issue but will be placed into target/debug/build/nargo_cli-*/out

[TomAFrench]

Closed by #4484