Change repeatN to support 0 as argument

This combinator now works equivalently to repeat.take(n)
typelevel · Oct 11, 2024 · b8a5bb4 · b8a5bb4
1 parent 9f51643
commit b8a5bb4
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diff --git a/core/shared/src/main/scala/fs2/Stream.scala b/core/shared/src/main/scala/fs2/Stream.scala
@@ -2574,8 +2574,9 @@ final class Stream[+F[_], +O] private[fs2] (private[fs2] val underlying: Pull[F,
     * }}}
     */
   def repeatN(n: Long): Stream[F, O] = {
-    require(n > 0, "n must be > 0") // same behaviour as sliding
-    if (n > 1) this ++ repeatN(n - 1)
+    require(n >= 0, "n must be >= 0")
+    if (n > 0) this ++ repeatN(n - 1)
+    else if (n == 0) Stream.empty
     else this
   }
 

diff --git a/core/shared/src/test/scala/fs2/StreamSuite.scala b/core/shared/src/test/scala/fs2/StreamSuite.scala
@@ -590,7 +590,7 @@ class StreamSuite extends Fs2Suite {
 
   property("repeatN") {
     forAll(
-      Gen.chooseNum(1, 200),
+      Gen.chooseNum(0, 200),
       Gen.chooseNum(1, 200).flatMap(i => Gen.listOfN(i, arbitrary[Int]))
     ) { (n: Int, testValues: List[Int]) =>
       assertEquals(