Add test for expire delay

Delaying the expiry of the drawable hitobject can potentially be dangerous and gameplay-altering when user inputs are accidentally handled. This is why I found a test necessary.

osu.Game.Rulesets.Taiko.Tests/Skinning/TestSceneDrawableSwellExpireDelay.cs

@@ -0,0 +1,41 @@
+// 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 NUnit.Framework;
+using osu.Game.Rulesets.Replays;
+using osu.Game.Rulesets.Scoring;
+using osu.Game.Rulesets.Taiko.Objects;
+using osu.Game.Rulesets.Taiko.Replays;
+using osu.Game.Rulesets.Taiko.Tests.Judgements;
+
+namespace osu.Game.Rulesets.Taiko.Tests.Skinning
+{
+    public partial class TestSceneDrawableSwellExpireDelay : JudgementTest
+    {
+        [Test]
+        public void TestExpireDelay()
+        {
+            const double swell_start = 1000;
+            const double swell_duration = 1000;
+
+            Swell swell = new Swell
+            {
+                StartTime = swell_start,
+                Duration = swell_duration,
+            };
+
+            Hit hit = new Hit { StartTime = swell_start + swell_duration + 50 };
+
+            List<ReplayFrame> frames = new List<ReplayFrame>
+            {
+                new TaikoReplayFrame(0),
+                new TaikoReplayFrame(2100, TaikoAction.LeftCentre),
+            };
+
+            PerformTest(frames, CreateBeatmap(swell, hit));
+
+            AssertResult<Hit>(0, HitResult.Ok);
+        }
+    }
+}