Migrate tests in detekt-rules-errorprone to junit

[marschwar]

Part of #4450

[codecov]

Codecov Report

Merging #4523 (a90418b) into main (0b36ff0) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##               main    #4523   +/-   ##
=========================================
  Coverage     84.42%   84.42%           
  Complexity     3323     3323           
=========================================
  Files           479      479           
  Lines         11139    11139           
  Branches       2039     2039           
=========================================
  Hits           9404     9404           
  Misses          700      700           
  Partials       1035     1035           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0b36ff0...a90418b. Read the comment docs.

[BraisGabin]

I'm having this same issue in #4459 (https://github.com/detekt/detekt/runs/4934052976?check_suite_focus=true#step:4:556)

It seems that our compile-test-snippets is a bit flaky. If I change the number of engines here:

detekt/detekt-test-utils/src/main/kotlin/io/github/detekt/test/utils/KotlinScriptEnginePool.kt

Line 13 in 4a89a25

private const val NUMBER_OF_ENGINES = 8

From 8 to 1 a lot of issues appear on main.

And, in my case if I change the number from 8 to 9 all works perfectly fine...

That PR is older than our PRs related with JUnit so JUnit is not the reason.

[marschwar]

Really strange...
At least it seems to be reproducable locally. Could it be possible that there are too many tests that try to access KotlinScriptEngine.compile(content) at the same time without any synchronization?

[BraisGabin]

Any idea why we have 8 of those? It doesn't seem that we are doing any parallel job here so with one it should be enough.

[marschwar]

No idea. It may also be something different entirely. It could well be, that I have some errors in the scripts to compile. I will investigate.

[marschwar]

In this case it seems like there is something wrong with the snippets in IgnoredReturnValueSpec.kt

[cortinico]

There is a merge conflict on this PR now. @marschwar are you able to take a look.
We also have #4541 that depends on this 👍