Add tests.

tests/src/test/scala/cats/tests/ReducibleSuite.scala

@@ -10,6 +10,8 @@ import cats.syntax.option._
 import cats.syntax.reducible._
 import org.scalacheck.Arbitrary
 
+import scala.collection.mutable
+
 class ReducibleSuiteAdditional extends CatsSuite {
 
   test("Reducible[NonEmptyList].reduceLeftM stack safety") {
@@ -22,6 +24,12 @@ class ReducibleSuiteAdditional extends CatsSuite {
     actual should ===(Some(expected))
   }
 
+  test("Reducible[NonEmptyList].reduceRightTo stack safety") {
+    val n = 100000L
+    val actual = (1L to n).toList.toNel.get.reduceRightTo(identity) { case (a, r) => r.map(_ + a) }.value
+    actual should ===((1L to n).sum)
+  }
+
   // exists method written in terms of reduceRightTo
   def contains[F[_]: Reducible, A: Eq](as: F[A], goal: A): Eval[Boolean] =
     as.reduceRightTo(_ === goal) { (a, lb) =>
@@ -76,6 +84,15 @@ class ReducibleSuiteAdditional extends CatsSuite {
     assert(contains(large, 10000).value)
   }
 
+  test("Reducible[NonEmptyList].reduceMapA can breakout") {
+    val notAllEven = NonEmptyList.of(2, 4, 6, 9, 10, 12, 14)
+    val out = mutable.ListBuffer[Int]()
+
+    notAllEven.reduceMapA { a => out += a; if (a % 2 == 0) Some(a) else None }
+
+    out.toList should ===(List(2, 4, 6, 9))
+  }
+
   // A simple non-empty stream with lazy `foldRight` and `reduceRightTo` implementations.
   case class NES[A](h: A, t: Stream[A]) {
     def toStream: Stream[A] = h #:: t