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Title
# development
a

ancient-vegetable-10556

12/20/2022, 5:22 PM
Having spent an hour (unsuccessfully) trying to unpick a unit test for a change that (apparently) drastically changes the rule graph in JVM land… I’ve noticed that there’s a bunch of modules that don’t declare their dependency rules in the
rules()
functions. So I was wondering if there’s enough information in the rule graph to statically generate correct and complete
rules
functions for a given module. Is there? What would it take to make that work?
(naïvely, having the param and return types from each
@rule
function would probably be enough, given each type should have the origin module embedded)
h

hundreds-father-404

12/20/2022, 5:38 PM
I’ve noticed that there’s a bunch of modules that don’t declare their dependency rules in the rules() functions.
Yeah, I think we should use this pattern more
So I was wondering if there’s enough information in the rule graph to statically generate correct and complete rules functions for a given module.
A major issue I can think of is unions. We don't know which you want activated, and it does matter—think toggling whether a backend is activatd
a

ancient-vegetable-10556

12/20/2022, 5:40 PM
Yeah, unions would be tricky
I’m wondering if having everything else be correct, and just knowing the rest of the rules are correct would be good enough
h

hundreds-father-404

12/20/2022, 5:41 PM
I think it would? I can't see any concerns. Could be complicated with handling plugins, I suppose
c

curved-television-6568

12/20/2022, 5:42 PM
(naïvely, having the param and return types from each
@rule
function would probably be enough, given each type should have the origin module embedded)
Like this?
Copy code
╰─❯ ./pants javac_check --help-advanced
`pants.backend.java.goals.check.javac_check` rule
-------------------------------------------------

Check javac compilation

Undocumented.

activated by  : pants.backend.experimental.java
returns       : CheckResults
takes 2 inputs: JavacCheckRequest, ClasspathEntryRequestFactory
awaits 3 gets : Get(CoarsenedTargets, Addresses, ..)
                Get(CoursierResolveKey, CoarsenedTargets, ..)
                Get(FallibleClasspathEntry, ClasspathEntryRequest, ..)
a

ancient-vegetable-10556

12/20/2022, 5:42 PM
Oooooh
c

curved-television-6568

12/20/2022, 5:43 PM
from there you can dig further:
Copy code
╰─❯ ./pants CoursierResolveKey --help-advanced

`pants.jvm.resolve.key.CoursierResolveKey` api type
---------------------------------------------------

CoursierResolveKey(name: 'str', path: 'str', digest: 'Digest')

activated by      : pants.backend.experimental.java, pants.jvm.resolve.key
dependencies      : builtins
                    pants.backend.experimental.go
                    pants.core
                    pants.engine.target
dependents        : pants.backend.experimental.java
                    pants.backend.experimental.scala
returned by 1 rule: pants.jvm.resolve.coursier_fetch.select_coursier_resolve_for_targets
consumed by 1 rule: pants.jvm.resolve.coursier_fetch.get_coursier_lockfile_for_resolve
used in 8 rules   : pants.backend.java.bsp.rules.bsp_java_compile_request
                    pants.backend.java.goals.check.javac_check
                    pants.backend.scala.bsp.rules.bsp_scala_compile_request
                    pants.backend.scala.bsp.rules.collect_thirdparty_modules
                    pants.backend.scala.goals.check.scalac_check
                    pants.jvm.classpath.classpath
                    pants.jvm.resolve.coursier_fetch.fetch_with_coursier
                    pants.jvm.resolve.coursier_fetch.materialize_classpath_for_tool
all this is in the json output of
./pants help-all
a

ancient-vegetable-10556

12/20/2022, 5:45 PM
OK, that’s spectacular.
😁 2
Thank you Andreas, if I get bored in the new year, I think I’ll be hacking on that
👍 1
It should make writing tests so much easier
❤️ 2
c

curved-television-6568

12/20/2022, 5:47 PM
yea, that was one of my motivating factors for adding the above info to the help system too.. 🙂
a

ancient-vegetable-10556

12/20/2022, 5:55 PM
🙂