Use a set when calculating resolve names

[thejcannon]

I saw errors with duplicates, so using a set (which is OK since this gets sorted) to stop that.

[kaos]

Is it not unexpected to get duplicates here?

Would be bad to hide a configuration error.. rather than giving an error (or at least a warning)

Do you have an example for what scenario you have where duplicates are a valid thing to have?

[kaos]

Ah, overlooked this was for the error message only. Nvm me then :)

[kaos]

I still wonder why you'd get duplicates though, and can you export them properly still for those that have dupes?

[thejcannon]

So I did --resolve=foo and saw (among others) pytest and flake8 twice. I was able to export flake8 just fine though...

[kaos]

Feels like there might be something registered twice then... perhaps 🤷🏽 👀

[kaos]

as such, that feels like a bug we want to squash rather than bury. I'll dig a little.

[kaos]

OK- now I see why it gets duplicated, and it's all right by design.

As we list all user resolves along with all tool resolves, and in case you have a custom lockfile for a tool, that gets duplicate entries in this list. So all good. 👍🏽

[kaos]

It was reassuring to see there was no duplicate entries registered, which helped guide me to look in the proper spot (which ironically was in the PR diff context already)

❯ pants GenerateToolLockfileSentinel --help-advanced

`pants.core.goals.generate_lockfiles.GenerateToolLockfileSentinel` api type
---------------------------------------------------------------------------

Tools use this as an entry point to say how to generate their tool lockfile.

Each language ecosystem should set up a union member of `GenerateLockfile`, like
`GeneratePythonLockfile`, as explained in that class's docstring.

Each language ecosystem should also subclass `GenerateToolLockfileSentinel`, e.g.
`GeneratePythonToolLockfileSentinel`. The subclass does not need to do anything - it is only used to know which language ecosystems tools correspond to.

Then, each tool should subclass their language ecosystem's subclass of `GenerateToolLockfileSentinel` and set up a rule that goes from the
subclass -> the language's lockfile request, e.g. BlackLockfileSentinel ->
GeneratePythonLockfile. Register `UnionRule(GenerateToolLockfileSentinel, MySubclass)`.

activated by       : pants.core
union members      : AutoflakeLockfileSentinel
                     BlackLockfileSentinel
                     CoverageSubsystemLockfileSentinel
                     DebugPyLockfileSentinel
                     DocformatterLockfileSentinel
                     DockerfileParserLockfileSentinel
                     Flake8LockfileSentinel
                     GoogleJavaFormatToolLockfileSentinel
                     IPythonLockfileSentinel
                     IsortLockfileSentinel
                     JarJarGeneratorLockfileSentinel
                     JarToolGenerateLockfileSentinel
                     JavaParserToolLockfileSentinel
                     JunitToolLockfileSentinel
                     MyPyExtraTypeStubsLockfileSentinel
                     MyPyLockfileSentinel
                     PyOxidizerLockfileSentinel
                     PytestLockfileSentinel
                     ScalaParserToolLockfileSentinel
                     ScalafmtToolLockfileSentinel
                     ScalatestToolLockfileSentinel
                     SetuptoolsLockfileSentinel
                     SetuptoolsSCMLockfileSentinel
                     StripJarToolLockfileSentinel
                     TwineSubsystemLockfileSentinel
                     YapfLockfileSentinel
dependencies       :
dependents         : pants.backend.docker
                     pants.backend.experimental.java
                     pants.backend.experimental.java.lint.google_java_format
                     pants.backend.experimental.python
                     pants.backend.experimental.python.packaging.pyoxidizer
                     pants.backend.experimental.scala
                     pants.backend.experimental.scala.lint.scalafmt
                     pants.backend.python
                     pants.backend.python.lint.autoflake
                     pants.backend.python.lint.black
                     pants.backend.python.lint.docformatter
                     pants.backend.python.lint.flake8
                     pants.backend.python.lint.isort
                     pants.backend.python.typecheck.mypy
                     pants.core
returned by 0 rules:
consumed by 0 rules:
used in 1 rule     : pants.core.goals.generate_lockfiles.generate_lockfiles_goal

[thejcannon]

Thanks for doing the homework <3