Optimize speed

[ErikSchierboom]

The Scala test runner is functional right now, but it is quite slow. In fact, it is so slow that the test runner times out before being able to return the results. We should speedup the test runner to not have it timeout.

Some possibly useful references:

• https://www.scala-lang.org/old/sites/default/files/linuxsoft_archives/docu/files/tools/fsc.html
• https://scalacenter.github.io/bloop/setup#sbt

[iHiD]

(cc @exercism/scala)

[MeerKatDev]

If you run sbt package it will package everything in a jar, which will be put under target/scala-2.12, that should avoid the steps of compiling and sbt warming up if used as executable

[iHiD]

@MeerKatDev Would you be able to PR that? Erik is off for the next 10 days and it would be nice to get Scala in the beta with a working test runner! :)

[ErikSchierboom]

@MeerKatDev It should be a question of using sbt package instead of sbt compile (I assume) in the Dockerfile (see https://github.com/exercism/scala-test-runner/blob/main/Dockerfile#L8), and then probably changing how the application is run in the bin/run.sh file (see https://github.com/exercism/scala-test-runner/blob/main/bin/run.sh#L57).

If you have Docker installed, you can verify that everything still works by running ./bin/run-tests-in-docker.sh. If there are no error messages, all is good (CI will verify this too).

[ErikSchierboom]

Even with #14 merged, the testing still times out :(

[MeerKatDev]

@ErikSchierboom I left a comment in the PR about it

[ErikSchierboom]

Commented

[MeerKatDev]

I don't understand, run-tests takes few seconds in the first cases. What's running so slow?

[ErikSchierboom]

That's what we're trying to find out :)

[MeerKatDev]

I mean, which command do you run? What exact operation? Until I cannot see on my local what's taking so long I cannot help :)

[ErikSchierboom]

There is of course a difference between running tests locally and on a remote machine that probably has less resources. Also, run-tests is running things locally, not in the Docker container so that is a huge difference. Do you have Docker installed?

[MeerKatDev]

I have, and docker is taking quite some time, but that's due to the building process, only that takes 50+ seconds