added a test

typelevel · Oct 10, 2021 · 24515bf · 24515bf
1 parent cde7f6b
commit 24515bf
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/core/shared/src/test/scala/fs2/StreamSuite.scala b/core/shared/src/test/scala/fs2/StreamSuite.scala
@@ -990,6 +990,14 @@ class StreamSuite extends Fs2Suite {
 
   group("parEvalMap") {
 
+    test("should preserve element ordering") {
+      forAllF { (stream: Stream[Pure, Int]) =>
+        val smaller = stream.map(i => math.abs(i % 10))
+        val delayed = smaller.covary[IO].parEvalMap(Int.MaxValue)(i => IO.sleep(i.millis).as(i))
+        delayed.compile.toList.assertEquals(smaller.toList)
+      }
+    }
+
     test("should launch no more than maxConcurrent") {
       forAllF { (stream: Stream[Pure, Unit], int: Int) =>
         val concurrency = math.abs(int % 20) + 1