Add RenameTupleApplySyntax Scalafix rewrite

scalafix/README.md

@@ -28,14 +28,14 @@ sbt scalafix github:typelevel/cats/v1.0.0
 
 - [x] cats.free.Inject is moved from cats-free to cats-core and renamed to cats.InjectK; cats.data.Prod is renamed to cats.data.Tuple2K; cats.data.Coproduct is renamed to cats.data.EitherK
 
+- [x] Apply syntax on tuple (e.g. (x, y, z).map3(...)) was moved from cats.syntax.tuple._ to cats.syntax.apply._ and renamed to mapN, contramapN and imapN respectively.
+
 # WIP
 
 - [ ] cats no longer publishes the all-inclusive bundle package "org.typelevel" % "cats", use cats-core, cats-free, or cats-law accordingly instead. If you need cats.free, use "org.typelevel" % "cats-free", if you need cats-laws use "org.typelevel" % "cats-laws", if neither, use "org.typelevel" % "cats-core".
 
 - [ ] FunctorFilter, MonadCombine, MonadFilter, MonadReader, MonadState, MonadTrans, MonadWriter and TraverseFilter are no longer in cats, the functionalities they provided are inhereted by the new cats-mtl project. Please check here for migration guide.
 
-- [ ] Apply syntax on tuple (e.g. (x, y, z).map3(...)) was moved from cats.syntax.tuple._ to cats.syntax.apply._ and renamed to mapN, contramapN and imapN respectively.
-
 - [ ] Several cats-core type class instances for cats.kernel were moved from their companion objects to separate traits and thus require imports from cats.instances.xxx._ (or the recommended import cats.implicits._) now. See #1659 for more details.
 
 - [ ] foldLeftM is removed from Free, use foldM on Foldable instead, see #1117 for detail.

scalafix/input/src/main/scala/fix/v1_0_0/RenameTupleApplySyntax.scala

@@ -0,0 +1,31 @@
+/* 
+rewrite = "scala:fix.v1_0_0.RenameTupleApplySyntax"
+ */
+package fix
+package to1_0_0
+
+object RenameTupleApplySyntaxTests {
+  import cats.{Eq, Semigroup}
+  import cats.instances.option._
+  import cats.instances.int._
+  import cats.syntax.tuple._
+
+  (Option(1), Option(2)).map2(_ + _)
+  (Option(1), Option(2), Option(3)).map3(_ + _ + _)
+  (Option(1), Option(2), Option(3), Option(4)).map4(_ + _ + _ + _)
+
+  case class Foo2(a: Int, b: Int)
+  case class Foo3(a: Int, b: Int, c: Int)
+  case class Foo4(a: Int, b: Int, c: Int, d: Int)
+
+  (Eq[Int], Eq[Int]).contramap2((f: Foo2) => (f.a, f.b))
+  (Eq[Int], Eq[Int], Eq[Int]).contramap3((f: Foo3) => (f.a, f.b, f.c))
+  (Eq[Int], Eq[Int], Eq[Int], Eq[Int]).contramap4((f: Foo4) => (f.a, f.b, f.c, f.d))
+
+  (Semigroup[Int], Semigroup[Int])
+    .imap2(Foo2.apply)(Function.unlift(Foo2.unapply))
+  (Semigroup[Int], Semigroup[Int], Semigroup[Int])
+    .imap3(Foo3.apply)(Function.unlift(Foo3.unapply))
+  (Semigroup[Int], Semigroup[Int], Semigroup[Int], Semigroup[Int])
+    .imap4(Foo4.apply)(Function.unlift(Foo4.unapply))
+}

scalafix/output/src/main/scala/fix/v1_0_0/RenameTupleApplySyntax.scala

@@ -0,0 +1,28 @@
+package fix
+package to1_0_0
+
+object RenameTupleApplySyntaxTests {
+  import cats.{Eq, Semigroup}
+  import cats.instances.option._
+  import cats.instances.int._
+  import cats.syntax.apply._
+
+  (Option(1), Option(2)).mapN(_ + _)
+  (Option(1), Option(2), Option(3)).mapN(_ + _ + _)
+  (Option(1), Option(2), Option(3), Option(4)).mapN(_ + _ + _ + _)
+
+  case class Foo2(a: Int, b: Int)
+  case class Foo3(a: Int, b: Int, c: Int)
+  case class Foo4(a: Int, b: Int, c: Int, d: Int)
+
+  (Eq[Int], Eq[Int]).contramapN((f: Foo2) => (f.a, f.b))
+  (Eq[Int], Eq[Int], Eq[Int]).contramapN((f: Foo3) => (f.a, f.b, f.c))
+  (Eq[Int], Eq[Int], Eq[Int], Eq[Int]).contramapN((f: Foo4) => (f.a, f.b, f.c, f.d))
+
+  (Semigroup[Int], Semigroup[Int])
+    .imapN(Foo2.apply)(Function.unlift(Foo2.unapply))
+  (Semigroup[Int], Semigroup[Int], Semigroup[Int])
+    .imapN(Foo3.apply)(Function.unlift(Foo3.unapply))
+  (Semigroup[Int], Semigroup[Int], Semigroup[Int], Semigroup[Int])
+    .imapN(Foo4.apply)(Function.unlift(Foo4.unapply))
+}

scalafix/rewrites/src/main/scala/fix/Cats_v1_0_0.scala

@@ -231,3 +231,26 @@ case class RenameInjectProdAndCoproduct(semanticCtx: SemanticCtx) extends Semant
   }
 
 }
+
+case class RenameTupleApplySyntax(semanticCtx: SemanticCtx) extends SemanticRewrite(semanticCtx) {
+
+  private[this] val renames: Map[String, String] =
+    (1 to 22)
+      .map { arity =>
+        Seq(
+          s"_root_.cats.syntax.Tuple${arity}CartesianOps.map$arity." -> "mapN",
+          s"_root_.cats.syntax.Tuple${arity}CartesianOps.contramap$arity." -> "contramapN",
+          s"_root_.cats.syntax.Tuple${arity}CartesianOps.imap$arity." -> "imapN"
+        )
+      }
+      .flatten
+      .toMap
+
+  def rewrite(ctx: RewriteCtx): Patch = {
+    ctx.tree.collect {
+      case t: Term.Name => rename(ctx, t, renames)
+      case t @ q"import cats.syntax.tuple._" =>
+        ctx.replaceTree(t, "import cats.syntax.apply._")
+    }.asPatch
+  }
+}