Enable -Xlint and -Werror

[som-snytt]

Linting on 2.13 such as required empty args,
inferred Any in sameElements of Array[_],
Timeout is double-valued, avoid Any.equals,
some elements unused, deprecations.
Allow JavaConverters.

Can't use nowarn and unused annotations
under 2.11/2.12.

[olafurpg]

LGTM 👍 Thank you for this contribution! I pushed an empty commit to trigger the CI.

[olafurpg]

Is there a way to silence the new warnings when compiling the codebase? I don't like fatal warnings because they are painful to work with when coding locally (example: commenting out a println statement introduces a fatal unused warning).

[som-snytt]

Thanks for taking a look.

OK, less-fatal warnings. Ideally there would be a turn-key or push-button way to enable that only for continuous integration later in the workflow.

I see I added some -Wconf, maybe I forgot to clean-compile. This is only my second time using -Wconf outside testing -Wconf.

Edit: I don't see warnings with + test on clean repo. Maybe there is some other interaction; I'm not an sbt power user, so I have nothing in my environment which might futz with compiler options.

The doc failure is Failed to parse -Wconf configuration.

Locally, scalafmt rejects my trailing comma and exits:

➜  munit git:(tweak/options) ./bin/scalafmt --check
--- /home/amarki/projects/munit/build.sbt
+++ /home/amarki/projects/munit/build.sbt-formatted
@@ -165,3 +165,3 @@
           //"-Werror",    // not 2.12
-          "-Xfatal-warnings",
+          "-Xfatal-warnings"
         )

Edit: I see there is sbt:munit> scalafixCheckAll which is 2.12 and shows the extra output. 🎉

[som-snytt]

Tweaked the scalafix task to use current 2.12. That didn't help warnings, so 2.12. scalac options avoid warning.

Probably scalacenter/sbt-scalafix#262 showing mangling of -Wconf.

Now I've lost the doc command that failed, so I haven't reproduced that.

[som-snytt]

Further exploration of perils of crossbuilding with lints.