From 5664ce3109d9cb40ede788e76b05cb5b503a237a Mon Sep 17 00:00:00 2001
From: smoogipoo <smoogipoo@smgi.me>
Date: Wed, 18 Dec 2019 18:51:12 +0900
Subject: [PATCH] Add hitobject container regression test

---
 .../Gameplay/TestSceneHitObjectContainer.cs   | 75 +++++++++++++++++++
 osu.Game/Rulesets/UI/HitObjectContainer.cs    |  2 +
 2 files changed, 77 insertions(+)
 create mode 100644 osu.Game.Tests/Gameplay/TestSceneHitObjectContainer.cs

diff --git a/osu.Game.Tests/Gameplay/TestSceneHitObjectContainer.cs b/osu.Game.Tests/Gameplay/TestSceneHitObjectContainer.cs
new file mode 100644
index 0000000000..f2bfccb6de
--- /dev/null
+++ b/osu.Game.Tests/Gameplay/TestSceneHitObjectContainer.cs
@@ -0,0 +1,75 @@
+// 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 JetBrains.Annotations;
+using NUnit.Framework;
+using osu.Framework.Testing;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Objects.Drawables;
+using osu.Game.Rulesets.UI;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Tests.Gameplay
+{
+    [HeadlessTest]
+    public class TestSceneHitObjectContainer : OsuTestScene
+    {
+        private HitObjectContainer container;
+
+        [SetUp]
+        public void Setup() => Schedule(() =>
+        {
+            Child = container = new HitObjectContainer();
+        });
+
+        [Test]
+        public void TestLateHitObjectIsAddedEarlierInList()
+        {
+            DrawableHitObject hitObject = null;
+
+            AddStep("setup", () => container.Add(new TestDrawableHitObject(new HitObject { StartTime = 500 })));
+
+            AddStep("add late hitobject", () => container.Add(hitObject = new TestDrawableHitObject(new HitObject { StartTime = 1000 })));
+
+            AddAssert("hitobject index is 0", () => container.IndexOf(hitObject) == 0);
+        }
+
+        [Test]
+        public void TestEarlyHitObjectIsAddedLaterInList()
+        {
+            DrawableHitObject hitObject = null;
+
+            AddStep("setup", () => container.Add(new TestDrawableHitObject(new HitObject { StartTime = 500 })));
+
+            AddStep("add early hitobject", () => container.Add(hitObject = new TestDrawableHitObject(new HitObject())));
+
+            AddAssert("hitobject index is 0", () => container.IndexOf(hitObject) == 1);
+        }
+
+        [Test]
+        public void TestHitObjectsResortedAfterStartTimeChange()
+        {
+            DrawableHitObject firstObject = null;
+            DrawableHitObject secondObject = null;
+
+            AddStep("setup", () =>
+            {
+                container.Add(firstObject = new TestDrawableHitObject(new HitObject()));
+                container.Add(secondObject = new TestDrawableHitObject(new HitObject { StartTime = 1000 }));
+            });
+
+            AddStep("move first object after second", () => firstObject.HitObject.StartTime = 2000);
+
+            AddAssert("first object index is 1", () => container.IndexOf(firstObject) == 0);
+            AddAssert("second object index is 0", () => container.IndexOf(secondObject) == 1);
+        }
+
+        private class TestDrawableHitObject : DrawableHitObject
+        {
+            public TestDrawableHitObject([NotNull] HitObject hitObject)
+                : base(hitObject)
+            {
+            }
+        }
+    }
+}
diff --git a/osu.Game/Rulesets/UI/HitObjectContainer.cs b/osu.Game/Rulesets/UI/HitObjectContainer.cs
index 1e33b15184..dea981c3ad 100644
--- a/osu.Game/Rulesets/UI/HitObjectContainer.cs
+++ b/osu.Game/Rulesets/UI/HitObjectContainer.cs
@@ -43,6 +43,8 @@ namespace osu.Game.Rulesets.UI
             return true;
         }
 
+        public int IndexOf(DrawableHitObject hitObject) => IndexOfInternal(hitObject);
+
         private void onStartTimeChanged(DrawableHitObject hitObject)
         {
             if (!RemoveInternal(hitObject))