handle breaking change in transitive dep scalameta 4.5.0

[bjaglin]

Follow-up of scalacenter/scalafix#1556. Not meant to be merged for now, but to centralize investigation.

[bjaglin]

=======
=> Diff
=======
--- obtained
+++ expected
@@ -24,9 +24,9 @@
∙
-  val fk1 = λ[FuncK[Option, List]](_.toList)
+  val fk1 = new FuncK[Option, List] { def apply[A$](a$: Option[A$]): List[A$] = a$.toList }
   val fk2 = new FuncK[Option, List] { def apply[A$](a$: Option[A$]): List[A$] = Nil }
-  val fk3 = λ[List ~> Option](_.headOption)
+  val fk3 = new (List ~> Option) { def apply[A$](a$: List[A$]): Option[A$] = a$.headOption }
   val fk4 = new (List ~> Option) { def apply[A$](xs: List[A$]): Option[A$] = xs.lastOption }
   val fk5 = new (({ type λ[α$] = Foo[α$, Int] })#λ ~> Option) { def apply[A$](a$: Foo[A$, Int]): Option[A$] = None }
-  val fk6 = λ[FuncK[List, λ[x => List[List[x]]]]](List(_))
-  val fk7 = λ[List ~> Option](_.headOption.map(identity))
+  val fk6 = new FuncK[List, ({ type λ[x] = List[List[x]] })#λ] { def apply[A$](a$: List[A$]): List[List[A$]] = List(a$) }
+  val fk7 = new (List ~> Option) { def apply[A$](a$: List[A$]): Option[A$] = a$.headOption.map(identity) }
   val fk8 = new (List ~> Option) { def apply[A$](list: List[A$]): Option[A$] = {
         
[info] RuleSuite:
[info] - fix/One.scala
[info] - fix/Alternative.scala
[info] - fix/KindProjectorRewrite.scala *** FAILED ***
[info]   see above (AbstractSemanticRuleSuite.scala:91)
[info] - fix/AddSerializable.scala
[info] - fix/TypedLambdaParamRewrite.scala
[info] - fix/AddImplicitNotFound.scala
[info] - fix/Compose.scala
[info] - fix/Invariant.scala
[info] - fix/Apply.scala
[info] - fix/AddSummoner.scala
[info] Run completed in 1 second, 66 milliseconds.
[info] Total number of tests run: 10
[info] Suites: completed 1, aborted 0
[info] Tests: succeeded 9, failed 1, canceled 0, ignored 0, pending 0
[info] *** 1 TEST FAILED ***

[bjaglin]

-@ import $ivy.`org.scalameta::scalameta:4.4.35`, scala.meta._ 
+@ import $ivy.`org.scalameta::scalameta:4.5.0`, scala.meta._ 
 @ """object Foo { val a = λ[FuncK[Option, List]](_.toList) }""".parse[Source].get 
 res1: Source = Source(
   stats = List(
     Defn.Object(
       mods = List(),
       name = Term.Name(value = "Foo"),
       templ = Template(
         early = List(),
         inits = List(),
         self = Self(name = , decltpe = None),
         stats = List(
           Defn.Val(
             mods = List(),
             pats = List(Pat.Var(name = Term.Name(value = "a"))),
             decltpe = None,
             rhs = Term.Apply(
              fun = Term.ApplyType(fun = Term.Name(value = "λ"), targs = List(Type.Apply(tpe = Type.Name(value = "FuncK"), args = List(Type.Name(value = "Option"), Type.Name(value = "List"))))),
-              args = List(Term.Select(qual = _, name = Term.Name(value = "toList")))
+              args = List(Term.AnonymousFunction(body = Term.Select(qual = _, name = Term.Name(value = "toList"))))
             )
           )
         ),
         derives = List()
       )
     )
   )
 )

The regression comes from scalameta/scalameta#2601

[bjaglin]

Marking this as ready for visibility. Following-up about the wider impact of this in scalacenter/scalafix#1556 (comment).

[bjaglin]

includes scalacenter/scalafix@4a2539c0#diff-ad2642dc77b3679e4ad2c7d3b2f59a2dcf48c1bf5b93a558a4fa44828315a34cR32

[bjaglin]

@sh0hei scalafix 0.10.0 is around the corner and running simulacrum-scalafix 0.5.0 as-is on scalafix 0.10.x will cause missed rewrites as identified by the tests above (and a warning for the user as described in the release notes). I can update this PR as soon as 0.10.0 is tagged, and I guess a 0.6.0 (only compatible with scalafix 0.10.x) would be useful?

[vendamere]

Closing since this was handled in #243 and have a draft release in #244
Thanks @bjaglin