scala_import support

[eed3si9n]

I noticed that jump-to-definition works only for internal dependencies on Metals.
I wonder if that's due to our usage of https://github.com/bazeltools/bazel-deps + scala_import(...).
Metals doctor contains a lot of

  Unknown target

[tgodzik]

I think someone else also reported it, I will need to double check what is going on

[tgodzik]

Might be related scalameta/metals#7507 (comment)

[adam-singer]

@tgodzik here is a minimal example where navigation fails (I also tried adding maven jars to hoepfully force it)

https://github.com/adam-singer/scalatest-example-bazel

Reports captured here
BSP Trace here

buildTarget/dependencyModules does return modules that includes jars and sources

Also a side note, would be nice if debugging could be implemented for bazelbsp, stumbled upon that. Is there any documentation on how to setup a debug agent with bazelbsp / scala / java ?

[tgodzik]

This should be fixed in scalameta/metals#7782

As for debugging, does it work for you with main classes? It should be soon implemented for test classes.

[adam-singer]

Will that solution work for dependencies that are synthetic ? Not sure where those end up when hitting this uri

I'm not sure I tried main classes, is there a trick to create a loader main class and then invoke the test classes? Not ideal tho if thats the case a generated main entrypoint could be done on the bazel side to start debugger on test classes?

[tgodzik]

Will that solution work for dependencies that are synthetic ? Not sure where those end up when hitting this uri

Not sure, we will need to check.

I'm not sure I tried main classes, is there a trick to create a loader main class and then invoke the test classes? Not ideal tho if thats the case a generated main entrypoint could be done on the bazel side to start debugger on test classes?

That's another option we are thinking of doing. Start with the debug flags, connect from metals.

[pielas]

@adam-singer
Could you clarify what you mean by 'debug agent'? Are you looking for a way to set up debugging in your IDE with bazel-bsp projects? Do you specifically need to be able to set up debugging through bazel-bsp, and is setting it up through Metals not enough?

I'm asking because, even if bazel-bsp says it doesn't support debugging, Metals can still run debug sessions for main and test class executions. I downloaded your example Bazel repo and was able to run a debugging session on the tests using not yet released version of metals:

I also added a Main.scala file and could debug it in VS Code using the "debug" button. You can find it here: https://github.com/pielas/scalatest-example-bazel/blob/main/main/Main.scala

In general, it should work out of the box in VS Code. If you want to debug tests from Metals, this feature should be available soon. Let me know if your use-case is different or you need something else.

[adam-singer]

@pielas Thats good to know, I thought that this would be provided by bazel-bsp as an assumption. What configuration steps did you need for setting up debug? Was it manual or is there enough in the stack of plugins that vscode properly identifies the jvm and class paths needed?

[pielas]

You just need Metals installed and everything should be detected automatically. You can use this repo as a minimal example to check if it works with your setup: https://github.com/pielas/scalatest-example-bazel. After importing it, the "run | debug" option should show up above your main class like in the screenshot below. If it does, you can also start a debug session using "Run -> Start Debugging".

In this commit you can see exactly what I needed to add to your repo to make it work: pielas/scalatest-example-bazel@e17253b. I just added the BUILD file to handle the new scala file, and also added a .bazelversion since my setup was using an old Bazel version by default.

[adam-singer]

@pielas got it working, I probably got messed up on some part of importing the project and/or needing to restart vscode. I do see run/debug for Main, tho don't see them for ExampleTest, maybe that has todo with the version I'm on Metals: 1.6.2 / Metals (Scala VSCode) 1.55.0 / bazel-bsp 4.0.1

[tgodzik]

The test support is not yet merged, I will do a release once it is finished.