Consider using `cargo-nextest`

[ogenev]

cargo-nexttest looks very promising -https://nexte.st/.

The only downside is that it cannot run doc tests, but we are not using them anyway.

[CPerezz]

Hey!

I've been giving this a try today.
So far the change is easy. There's just one catch.

cargo-nextest will by default run on all available threads.
This is fine for most of the codebase except for ethportal-peertest::self_peertest a d ethportal-peertest::rpc_server groups of tests.

In these, we actually need to launch a trin client. And the problem is that once one test takes the ownership of the file-descriptor which holds the IO address for the listener of trin, the rest of tests panic due to the error of the address to listen to being already taken:

trin/testing/ethportal-peertest/src/lib.rs:45:56:
called `Result::unwrap()` on an `Err` value: "Failed to start discv5 server: Io(Os { code: 48, kind: AddrInUse, message: \"Address already in use\" })"
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

I tried to go the setup/teardown route. Ideally you just need to setup
https://github.com/CPerezz/trin/blob/9d8ba360359d9dab9e4226fd16161463ec730b67/testing/ethportal-peertest/tests/self_peertest.rs#L373`
and the rest is about sharing the instance cross-tests. But static variables or crates like ctor or lazy_static don't actually support async/await.

Retunring the Future (which is valid behaviour within static for example) to then call await within the test would be ok. The problem is that the Future won't actually work as the syncronisation doesn't happen.

What I can definitely say is that the speedup in test execution is notable. Is that the only thing you were interested?

cc: @ogenev

[ogenev]

@CPerezz thanks for the info, should we run ethportal-peertest with the default test runner and the rest of the crates with cargo-nextest?

[CPerezz]

@ogenev So I made a solution with a Mutex to do common setup for all tests (that share Subnetwork config ofc).
So far, something is not right as the Mutex seems to not be doing anything.

I understood why. cargo-nextest is getting each test binary and launching it in parallel with tokio. That means, that each test has no context whatsoever with the others.
Hence, any Mutex or static I create will simply be worthless.

Give me a couple days to actually see if I can unify the setup/teardown. And just rely on cargo-nextest. Otherwise yes, the simplest solution will be to use both test runners.
cargo-nextest has experimental support for scripts. So will explore it prior to calling it a day.