PreTyperComponent

This jspretyper phase prepares a fix for issue SI-9487 in the case of anonymous classes that extend js.Any.

During typer, due to a bug (SI-9487), Scalac transfroms some public method definitions of a quite specific syntactic form of anonymous classes into private methods. This affects both methods and field accessors. This phase identifies any anonymous class and adds a @WasPublicBeforeTyper annotation on its public methods and fields. After the typer in jsinterop the anonymous classes are fixed if they extend js.Any using the annotations as reference.

As an example:

class $anon extends ... {
  val foo = ???
  var bar = ???
  def baz = ???
  private val foo2 = ???
  private var bar2 = ???
  private def baz2 = ???
}

Would become:

class $anon extends ... {
  @WasPublicBeforeTyper val foo = ???
  @WasPublicBeforeTyper var bar = ???
  @WasPublicBeforeTyper def baz = ???
  private val foo2 = ???
  private var bar2 = ???
  private def baz2 = ???
}

And after typer (if has SI-9487) will be:

class $anon extends ... {
  @WasPublicBeforeTyper private[this] var foo = ???
  private <stable> <accessor> def foo = ??? // Needs fix

  @WasPublicBeforeTyper private[this] var bar = ???
  private <accessor> def bar = ??? // Needs fix
  private <accessor> def bar_=(...) = ??? // Needs fix

  @WasPublicBeforeTyper private def baz = ??? // Needs fix
  ...
}