Neg tests could infer `//error` and `// error` as the same thing

[ashwinbhaskar]

When writing tests in neg package we have the option of giving // error at the end of a line to indicate a compilation error on that line. The space between // and error is strictly required and I have spent a lot of time figuring out why my tests in the neg folder did not work. Apparently I missed the space.

Can we simplify this by treating both //error and // error as the same?

[nicolasstucki]

It would be better to have a single and homogeneous format.

What we could do is to identify //error in the test framework an emit a warning. This way if the test fail because the error tag was wrong, there will be a warning just before the test failure.

[ashwinbhaskar]

It would be better to have a single and homogeneous format.

What we could do is to identify //error in the test framework an emit a warning. This way if the test fail because the error tag was wrong, there will be a warning just before the test failure.

@nicolasstucki Makes sense. Where should I start from if I am going to do this enhancement?

[nicolasstucki]

Probably here

https://github.com/lampepfl/dotty/blob/master/compiler/test/dotty/tools/vulpix/ParallelTesting.scala#L657

[ashwinbhaskar]

Can you assign this to me?

[ashwinbhaskar]

@nicolasstucki Is there any logger that I can use to print a warning? Or can I just go ahead with a println?

[nicolasstucki]

Try echo like in

https://github.com/lampepfl/dotty/blob/master/compiler/test/dotty/tools/vulpix/ParallelTesting.scala#L609

[ashwinbhaskar]

Try echo like in

https://github.com/lampepfl/dotty/blob/master/compiler/test/dotty/tools/vulpix/ParallelTesting.scala#L609

Thank you. Does the PR look okay? #7062