compileErrors doesn't return all errors

[robstoll]

Consider the following:

assertNoDiff(
   compileErrors("1.isInstanceOf[String]"),
  "cannot test if value of type Int is a reference of class String"
)

[erikerlandson]

I am also seeing this, in coulomb. My compiler is 3.4.2-RC1-xxxxx-NIGHTLY

// this is returning empty error list
val x = compileErrors("3.withUnit[Second] * 5d.withUnit[Kilogram]")
println(s"x= $x")

However if I try to compile, this errors out (as it should)

val x = 3.withUnit[Second] * 5d.withUnit[Kilogram]

[error] -- [E172] Type Error: /home/eje/git/coulomb/core/src/test/scala/coulomb/quantity.scala:232:58 
[error] 232 |        val x = 3.withUnit[Second] * 5d.withUnit[Kilogram]
[error]     |                                                          ^
[error]     |No given instance of type algebra.ring.MultiplicativeSemigroup[Double | Int] was found for parameter alg of method * in object Quantity
[error] one error found

[erikerlandson]

In my case this issue may be duplicate of #711

[tgodzik]

Looking again at this, it seems in the first case it might be an issue within the compiler, though ideally isInstanceOf would just return false instead of failing. So it seems the munit behaviour is by mistake correct.

@erikerlandson was your issue fixed by using the method in #711 ?

[robstoll]

@tgodzik I am afraid I am not sure if I get what you mean. I guess you mean the underlying of compileErrors in the compiler is buggy right and that's way it is hard for munit to fix this. Correct?

[tgodzik]

@tgodzik I am afraid I am not sure if I get what you mean. I guess you mean the underlying of compileErrors in the compiler is buggy right and that's way it is hard for munit to fix this. Correct?

Actually, we were missing transient keyword, which is suggested to be used in this specific case. You can try using this method:

transparent inline def compileErrorsFixed(inline code: String): String = {
    val errors = scala.compiletime.testing.typeCheckErrors(code)
    errors
      .map { error =>
        val indent = " " * (error.column - 1)
        val trimMessage = error.message.linesIterator
          .map { line =>
            if line.matches(" +") then ""
            else line
          }
          .mkString("\n")
        val separator = if error.message.contains('\n') then "\n" else " "
        s"error:$separator$trimMessage\n${error.lineContent}\n$indent^"
      }
      .mkString("\n")
  }

explicitely to see if adding the keyword helps in your case

[erikerlandson]

@tgodzik coincidentally I made a design change to what I was doing and it caused this error to stop happening to me. It must have changed the specific compiler error so that compileErrors was catching it. So my code no longer reproduces this to test a fix :/

[tgodzik]

Ok, let us know if anything pops up again.

Coming back to the initial error in this issue it seems this is caused by a bug in the compiler or might actually be on purpose. Will ask.

[tgodzik]

So it looks like this is an actual expected behaviour as the error in 1.isInstanceOf[String] is produced in another phase. If needed please raise an issue in the compiler @robstoll