Load external denylist entries via ServiceLoader

[erawhctim]

Summary

Allow consumers to supply their own DenyListedEntrys via a ServiceLoader interface. Fixes #241.

Open to suggestions on any of the names, or if there's a preferred use of ServiceLoader (it's new to me!)

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[erawhctim]

when running spotlessApply locally, I hit an error that I'm not sure what to do with. Subsequent spotless runs seemed to want to delete various files in my staging area 🤔 Have you run into this before?

> Task :spotlessKotlinExternalApply FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':spotlessKotlinExternalApply'.
> java.nio.file.FileAlreadyExistsException: /Users/mitchware/Desktop/Workspace/erawhctim-slack-lints/build/spotless/spotlessKotlinExternal/slack-lint-checks/src/test/java/slack/lint/denylistedapis/TestEntriesLoader.kt -> /Users/mitchware/Desktop/Workspace/erawhctim-slack-lints/slack-lint-checks/src/test/java/slack/lint/denylistedapis/TestEntriesLoader.kt

Same issue happened with the DenyListedEntryLoader interface.

[ZacSweers]

For the spotless issue, just re-run it again without configuration cache. It's a weird issue with spotless that I don't really understand :/

[ZacSweers]

You should be able to do something like ServiceLoader.load(...).iterator().toSet()

[erawhctim]

nice, the more concise the better. I'm not seeing an applicable toSet() call to use here, but I might be missing something.

[ZacSweers]

maybe .iterator().asSequence().toSet()

[ZacSweers]

Would you mind adding an experimental annotation for this? None of this is a stable API anyway, but want to make it doubly-clear here :). Can call it ExperimentalSlackLintApi

[ZacSweers]

Let's also name this DenyListedEntryProvider and make it have a function instead (i.e. getEntries()) that takes a JavaContext. Then let's lazily load these in the element handler and provide the available context to it, so we can minimize loading (especially if there are entries provided that don't apply in certain contexts).

[erawhctim]

oh yeah sure, good call.