Add test for errors involving module classes

[odersky]

Ideally, we should make this into a proper test with check files.

[nicolasstucki]

Why didn't you add the tests/neg/module-class-name.check check file?

[odersky]

Why didn't you add the tests/neg/module-class-name.check check file?

I never can figure out how to generate that check file in the first place. Can you add it?

It would be easy if it was just copy output to check. Please, everyone, let's bring that back. I hate obscure sbt commands that only work in some contexts but not in others.

[nicolasstucki]

Done.

To add those, add the check file and run the test with --update-checkfiles

$ touch tests/neg/module-class-name.check
$ sbt 
> testCompilation tests/neg/module-class-name.scala --update-checkfiles

testCompilation --help could be used to remember the command.

@anatoliykmetyuk could you have a look at how we could make the checkfile creation process simpler?

[anatoliykmetyuk]

@nicolasstucki ok, I'll have a look at it.

[biboudis]

And document it somewhere as well! 🙈

[nicolasstucki]

testCompilation --help might be a good place to add extra documentation.

[anatoliykmetyuk]

The issue with testCompilation is that sometimes you need testOnly.