bsp: Implementing buildTarget/cleanCache

[hmemcpy]

Fixes #6569

This command is invoked by IntelliJ whenever a Rebuild operation is called. Unfortunately, because it's not implemented, this causes bsp-imported projects in IntelliJ to hang when asking to rebuild.

It works fine in bloop-imported projects because bloop implements this API.

[lightbend-cla-validator]

Hi @hmemcpy,

Thank you for your contribution! We really value the time you've taken to put this together.

Before we proceed with reviewing this pull request, please sign the Lightbend Contributors License Agreement:

https://www.lightbend.com/contribute/cla

[hmemcpy]

@adpi2 hello, sorry for the ping. Unfortunately, this isn't actually working, and I really have no idea why :(
The test passes, but when I actually try to test this in a local test project, when I call cleanCache from IntelliJ (or even send the json payload via sbt -bsp) I immediately get a shutdown.

I really don't know what I'm missing... any tips appreciated!

[hmemcpy]

Update! I got it working... somehow. I made sure to clean everything up, do a publishLocal, followed by a "reboot dev" in my test project... and voilla!
Will finalize the PR soon.

[adpi2]

@hmemcpy Thanks for pinging me! It is great that you are working on it.

I tested it locally and it seems to work. Make sure you clean the .sbt cache after running publishLocal with:

rm -Rf ~/.sbt/boot/scala-2.12.14/org.scala-sbt/sbt/1.5.5-SNAPSHOT

Otherwise the launcher loads the old cached jars rather than the new ones.

Another way to test the buildTarget/cleanCache request is to add a test in BuildServerTest.

You can run it with:

sbt:sbt> serverTestProj/testOnly testpkg.BuildServerTest

[hmemcpy]

@adpi2 I guess initially I had old jars in the cache. I'll test this a bit more and will mark the PR as done. Thanks again for the help!

[hmemcpy]

And it's good to go!

[adpi2]

Thanks @hmemcpy!

Most of the comments are suggestions. But I think it is important to check in the test that buildTarget/cleanCache empties the class directory.

[hmemcpy]

Thanks for the comments! My copy-pasting was obvious here :)
I'll make the changes and will figure out how to check for empty directories!

[adpi2]

LGTM

[hmemcpy]

Oops, temporarily marking this as draft. It looks like the results.size == targets.size isn't a good check. I just noticed that out of the 3 targets, I get only 2 results back. The sent targets are:

  "targets": [
    {
      "uri": "file:/Users/hmemcpy/git/sbt-playground/#root-build"
    },
    {
      "uri": "file:/Users/hmemcpy/git/sbt-playground/#root/Compile"
    },
    {
      "uri": "file:/Users/hmemcpy/git/sbt-playground/#root/Test"
    }

And I get back just two. Unfortunately I don't know what they are, since it's a Unit result. Is, perhaps, root-build not a "real" target?

Update: I changed Keys.clean to Keys.bspBuildTarget and indeed, the two results I get back are Compile and Test, the -build is not present.

I understand this somewhat a synthetic target, perhaps I can filter it out when doing the comparison?

[hmemcpy]

Alright... I managed to implement a solution for both "Rebuild Project" (which includes the root build), as well as a regular "Rebuild module" (which includes the exact targets to rebuild).

Would love any suggestions to improve this!

[adpi2]

I don't see any obvious way to clean the build.sbt target. So this solution seems ok to me.

[hmemcpy]

TYVM! :)