In Apply.semigroup test replace ListWrapper with Option (#2827)

* In  Apply.semigroup test replace  ListWrapper with Option

* fmt

* address feedback

Author: kailuowang

core/src/main/scala/cats/Apply.scala

@@ -216,6 +216,13 @@ trait Apply[F[_]] extends Functor[F] with InvariantSemigroupal[F] with ApplyArit
 }
 
 object Apply {
+
+  /**
+   * This semigroup uses a product operation to combine `F`s.
+   * If the `Apply[F].product` results in larger `F` (i.e. when `F` is a `List`),
+   * accumulative usage of this instance, such as `combineAll`, will result in
+   * `F`s with exponentially increasing sizes.
+   */
   def semigroup[F[_], A](implicit f: Apply[F], sg: Semigroup[A]): Semigroup[F[A]] =
     new ApplySemigroup[F, A](f, sg)
 }

tests/src/test/scala/cats/tests/ApplicativeSuite.scala

@@ -46,10 +46,10 @@ class ApplicativeSuite extends CatsSuite {
   }
 
   {
-    implicit val listwrapperApply = ListWrapper.applyInstance
-    implicit val listwrapperSemigroup = Apply.semigroup[ListWrapper, Int]
-    checkAll("Apply[ListWrapper].semigroup", SemigroupTests[ListWrapper[Int]].semigroup)
+    val optionSemigroupFromApply = Apply.semigroup[Option, Int]
+    checkAll("Apply[Option].semigroup", SemigroupTests[Option[Int]](optionSemigroupFromApply).semigroup)
   }
+
   {
     implicit val listwrapperApplicative = ListWrapper.applicative
     implicit val listwrapperCoflatMap = Applicative.coflatMap[ListWrapper]