Add test case for fading hold note

osu.Game.Rulesets.Mania.Tests/Skinning/TestSceneHoldNote.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
 using osu.Framework.Bindables;
@@ -26,6 +27,18 @@ namespace osu.Game.Rulesets.Mania.Tests.Skinning
             });
         }
 
+        [Test]
+        public void TestFadeOnMiss()
+        {
+            AddStep("miss tick", () =>
+            {
+                foreach (var holdNote in holdNotes)
+                    holdNote.ChildrenOfType<DrawableHoldNoteHead>().First().MissForcefully();
+            });
+        }
+
+        private IEnumerable<DrawableHoldNote> holdNotes => CreatedDrawables.SelectMany(d => d.ChildrenOfType<DrawableHoldNote>());
+
         protected override DrawableManiaHitObject CreateHitObject()
         {
             var note = new HoldNote { Duration = 1000 };