[WIP] Port TraverseSuite to Scala 3

core/src/test/scala-3/cats/derived/TraverseSuite.scala

@@ -0,0 +1,65 @@
+package cats
+package derived
+
+import cats.laws.discipline.{SerializableTests, TraverseTests}
+
+class TraverseSuite extends KittensSuite {
+  import TestDefns.*
+  import TraverseSuite.*
+
+  def testTraverse(context: String)(implicit
+      iList: Traverse[IList],
+      tree: Traverse[Tree],
+      genericAdt: Traverse[GenericAdt],
+      optList: Traverse[OptList],
+      listSnoc: Traverse[ListSnoc],
+      andChar: Traverse[AndChar],
+      interleaved: Traverse[Interleaved]
+  ): Unit = {
+    checkAll(s"$context.Traverse[IList]", TraverseTests[IList].traverse[Int, Double, String, Long, Option, Option])
+    checkAll(s"$context.Traverse[Tree]", TraverseTests[Tree].traverse[Int, Double, String, Long, Option, Option])
+    checkAll(
+      s"$context.Traverse[GenericAdt]",
+      TraverseTests[GenericAdt].traverse[Int, Double, String, Long, Option, Option]
+    )
+    checkAll(s"$context.Traverse[OptList]", TraverseTests[OptList].traverse[Int, Double, String, Long, Option, Option])
+    checkAll(
+      s"$context.Traverse[ListSnoc]",
+      TraverseTests[ListSnoc].traverse[Int, Double, String, Long, Option, Option]
+    )
+    checkAll(s"$context.Traverse[AndChar]", TraverseTests[AndChar].traverse[Int, Double, String, Long, Option, Option])
+    checkAll(
+      s"$context.Traverse[Interleaved]",
+      TraverseTests[Interleaved].traverse[Int, Double, String, Long, Option, Option]
+    )
+    checkAll(s"$context.Traverse is Serializable", SerializableTests.serializable(Traverse[Tree]))
+  }
+
+  {
+    import auto.traverse.given
+    testTraverse("auto")
+  }
+
+  {
+    import semiInstances._
+    testTraverse("semiauto")
+  }
+}
+
+object TraverseSuite {
+  import TestDefns._
+
+  type OptList[A] = Option[List[A]]
+  type ListSnoc[A] = List[Snoc[A]]
+  type AndChar[A] = (A, Char)
+
+  object semiInstances {
+    implicit val iList: Traverse[IList] = semiauto.traverse
+    implicit val tree: Traverse[Tree] = semiauto.traverse
+    implicit val genericAdt: Traverse[GenericAdt] = semiauto.traverse
+    implicit val optList: Traverse[OptList] = semiauto.traverse
+    implicit val listSnoc: Traverse[ListSnoc] = semiauto.traverse
+    implicit val andChar: Traverse[AndChar] = semiauto.traverse
+    implicit val interleaved: Traverse[Interleaved] = semiauto.traverse
+  }
+}