Add classpath_depth to allow controlling transitive dependency depth

[brian-mcnamara]

The work here it to add a classpath_depth option to the bazel project view. This configuration allows the classpath of the project to be reduced, where 1 is only the dependencies required for the targets imported to compile. Setting it less then 0 disables the filtering and the existing functionality to be used.

This allows functionality similar to the IJ bazel plugin, which excludes transitives and provides a partial classpath. I would also like this concept be brought into IJ, but starting here

[plaird]

Cool feature. Doesn't Eclipse complain though if it can't find necessary classes when it launches tests?

[github-actions]

Test Results

 38 files  ±0   38 suites  ±0   21s ⏱️ -1s
 55 tests ±0   54 ✅ ±0   1 💤 ±0  0 ❌ ±0 
110 runs  ±0  100 ✅ ±0  10 💤 ±0  0 ❌ ±0 

Results for commit 0e36caa. ± Comparison against base commit 6de8135.

♻️ This comment has been updated with latest results.

[brian-mcnamara]

Cool feature. Doesn't Eclipse complain though if it can't find necessary classes when it launches tests?

Yes, good call out. I need to think though this one, I know IJ invokes bazel to remove the classpath in the IDE from causing issues, may have to do something similar, or figure out a way to store the actual runtime classpath outside Eclipse's project model.

[guw]

@brian-mcnamara I think it would be good to capture the motivation for this change. Perhaps we should open an issue and add a few screenshots or some date showing before and/or after timings/memory consumption?

[brian-mcnamara]

I renamed import_depth to runtime_import_depth due to JetBrains BSP plugin using import_depth flag as a helper to specify the depth of source projects to pull into the project view during sync.

[guw]

hmm ... should we use classpath_depth?

[brian-mcnamara]

hmm ... should we use classpath_depth?

Not opposed to that, the only thing that may be confusing is setting the value to 0, which in the current implementation means exclude all runtime dependencies, but with classpath_depth, 0 to me would indicate even compile time classpath are excluded. I could just subtract 1 from the input to get around this and make it more intuitive.