Error message for unimplemented members does not pretty print methods correctly

[jvican]

[error] -- Error: /data/rw/code/scala/loop/rework/src/main/scala/bloop/State.sca
la:110:8
[error] 110 |  class MyRunner(msg: String) extends sbt.testing.Runner {
[error]     |        ^
[error]     |class MyRunner needs to be abstract, since:[error]     |it has 4 unimplemented members.
[error]     |/** As seen from class MyRunner, the missing signatures are as foll
ows.
[error]     | *  For convenience, these are usable as stub implementations.
[error]     | */
[error]     |  def args: (): Array[String] = ???
[error]     |  def done: (): String = ???[error]     |  def remoteArgs: (): Array[String] = ???
[error]     |  def tasks: (x$0: Array[sbt.testing.TaskDef]): Array[sbt.testing.T
ask] = ???

As you see, def args: (): Array[String] = ??? has an extra : before the parameter list.

[drdozer]

I think I hit this today.

[error] 12 |  implied ErrMonad for Monad[Err] {
[error]    |          ^
[error]    |object creation impossible, since:
[error]    |it has 3 unimplemented members.
[error]    |/** As seen from module class ErrMonad$, the missing signatures are as follows.
[error]    | *  For convenience, these are usable as stub implementations.
[error]    | */
[error]    |  // Members declared in cats.Applicative
[error]    |  def pure: [A](x: A): ct.Err.Err[A] = ???

This definitely does not copy-paste.

[som-snytt]

Me, too. The extra arrow for method type and the marginal VBAR both make the convenience less convenient for quick copy/paste. (And quick trials in REPL is what this is useful for. It would be nice to drop me into multiline edit with the stubs added, with no copy/paste.)

scala> class C extends Seq[String]
1 |class C extends Seq[String]
  |      ^
  |      class C needs to be abstract, since:
  |      it has 3 unimplemented members.
  |      /** As seen from class C, the missing signatures are as follows.
  |       *  For convenience, these are usable as stub implementations.
  |       */
  |        // Members declared in scala.collection.IterableOnce
  |        def iterator: => Iterator[String] = ???
  |        
  |        // Members declared in scala.collection.SeqOps
  |        def apply(i: Int): String = ???
  |        def length: => Int = ???

versus

scala> class C extends Seq[String]
             ^
       error: class C needs to be abstract.
       Missing implementations for 3 members. Stub implementations follow:
         // Members declared in scala.collection.IterableOnce
         def iterator: Iterator[String] = ???

         // Members declared in scala.collection.SeqOps
         def apply(i: Int): String = ???
         def length: Int = ???