Type Mismatch Error for the same type

[LightSystem]

Hi @arainko,
First of all thank you for this awesome library! It is a godsend that is helping us migrate to Scala 3 in a more painless manner 😌

I've just started using it for some of our case class transformations and have encountered a curious issue. Seems to have to do with companion objects or objects in general.
Let's imagine I have these case classes:

case class A(anotherCaseClass: AnotherCaseClass)
object A:
  case class AnotherCaseClass(name: String)
  case class B(anotherCaseClass: AnotherCaseClass)

AnotherCaseClass can be simple or complex, it doesn't matter. If I then do:

val a = A(AnotherCaseClass("test"))
a.to[B]

I get the following compilation error:

[error] -- [E007] Type Mismatch Error: /some/file:95:11 
[error] 95 |    a.to[B]
[error]    |           ^
[error]    |           Found:    A.AnotherCaseClass | dest
[error]    |           Required: A.AnotherCaseClass
[error]    |----------------------------------------------------------------------------
[error]    |Inline stack trace
[error]    |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
[error]    |This location contains code that was inlined from LiftTransformationModule.scala:15
[error]    |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
[error]    |This location contains code that was inlined from LiftTransformationModule.scala:15
[error]    |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
[error]    |This location contains code that was inlined from LiftTransformationModule.scala:15

I'm using scala 3.2.1 and ducktape version 0.1.1.

Thanks again. If I get some time I'll try to research this problem deeper by looking into ducktape's codebase though metaprogramming is something I'm not very familiar with yet.

[arainko]

Hey @LightSystem! Thanks for reporting the issue and sorry for the inconvenience that it causes!

I can reproduce it locally and will be taking a closer look at it in the following days. The issue seems to stem from the placement of the case class in the companion object, just as you said.

In the meantime a workaround (you probably figured it out already but I'm putting it out there in case someone also stumbles upon this) is to move out the definition of AnotherCaseClass out of the companion object of A, so the code would look like this:

case class A(anotherCaseClass: AnotherCaseClass)
case class AnotherCaseClass(name: String)

object A:
  case class B(anotherCaseClass: AnotherCaseClass)

[arainko]

Some further findings:

It turns out that if you refer to SomeOtherClass as A.SomeOtherClass in B, like this:

case class A(anotherCaseClass: A.AnotherCaseClass)

object A {
  case class AnotherCaseClass(name: String)
  case class B(anotherCaseClass: A.AnotherCaseClass)
}

it's all fine and dandy, but once you get rid of the A. prefix in B it goes back to being broken. Feels like I'm taking crazy pills.

So that'd make it the go-to workaround for this issue for now - I'm investigating further 😸

[arainko]

Managed to pinpoint the cause and resolve the issue, more details in #27. ducktape 0.1.2 with the fix applied is on its way to Maven Central. Once again thanks for using the library and reporting the issue @LightSystem!