Add basic test for difficulty switching

osu.Game.Tests/Visual/Editing/TestSceneDifficultySwitching.cs

@@ -0,0 +1,91 @@
+// 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;
+using System.Linq;
+using NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Testing;
+using osu.Game.Beatmaps;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Screens.Edit;
+using osu.Game.Screens.Edit.Components.Menus;
+using osu.Game.Tests.Beatmaps.IO;
+using osuTK.Input;
+
+namespace osu.Game.Tests.Visual.Editing
+{
+    public class TestSceneDifficultySwitching : ScreenTestScene
+    {
+        private BeatmapSetInfo importedBeatmapSet;
+
+        [Resolved]
+        private OsuGameBase game { get; set; }
+
+        private Editor editor;
+
+        [Resolved]
+        private BeatmapManager beatmaps { get; set; }
+
+        [SetUpSteps]
+        public void SetUp()
+        {
+            AddStep("import test beatmap", () => importedBeatmapSet = ImportBeatmapTest.LoadOszIntoOsu(game, virtualTrack: true).Result);
+
+            AddStep("set current beatmap", () => Beatmap.Value = beatmaps.GetWorkingBeatmap(importedBeatmapSet.Beatmaps.First()));
+            AddStep("push loader", () => Stack.Push(new EditorLoader()));
+
+            AddUntilStep("wait for editor to load", () => Stack.CurrentScreen is Editor);
+            AddStep("store editor", () => editor = (Editor)Stack.CurrentScreen);
+        }
+
+        [Test]
+        public void TestBasicSwitch()
+        {
+            BeatmapInfo targetDifficulty = null;
+
+            AddStep("set target difficulty", () => targetDifficulty = importedBeatmapSet.Beatmaps.Last(beatmap => !beatmap.Equals(Beatmap.Value.BeatmapInfo)));
+            switchToDifficulty(() => targetDifficulty);
+            confirmEditingBeatmap(() => targetDifficulty);
+
+            AddStep("exit editor", () => Stack.Exit());
+            // ensure editor loader didn't resume.
+            AddAssert("stack empty", () => Stack.CurrentScreen == null);
+        }
+
+        private void switchToDifficulty(Func<BeatmapInfo> difficulty)
+        {
+            AddUntilStep("wait for menubar to load", () => editor.ChildrenOfType<EditorMenuBar>().Any());
+            AddStep("open file menu", () =>
+            {
+                var menuBar = editor.ChildrenOfType<EditorMenuBar>().Single();
+                var fileMenu = menuBar.ChildrenOfType<DrawableOsuMenuItem>().First();
+                InputManager.MoveMouseTo(fileMenu);
+                InputManager.Click(MouseButton.Left);
+            });
+
+            AddStep("open difficulty menu", () =>
+            {
+                var difficultySelector =
+                    editor.ChildrenOfType<DrawableOsuMenuItem>().Single(item => item.Item.Text.Value.ToString().Contains("Change difficulty"));
+                InputManager.MoveMouseTo(difficultySelector);
+            });
+            AddWaitStep("wait for open", 3);
+
+            AddStep("switch to target difficulty", () =>
+            {
+                var difficultyMenuItem =
+                    editor.ChildrenOfType<DrawableOsuMenuItem>()
+                          .Last(item => item.Item is DifficultyMenuItem difficultyItem && difficultyItem.Beatmap.Equals(difficulty.Invoke()));
+                InputManager.MoveMouseTo(difficultyMenuItem);
+                InputManager.Click(MouseButton.Left);
+            });
+        }
+
+        private void confirmEditingBeatmap(Func<BeatmapInfo> targetDifficulty)
+        {
+            AddUntilStep("current beatmap is correct", () => Beatmap.Value.BeatmapInfo.Equals(targetDifficulty.Invoke()));
+            AddUntilStep("current screen is editor", () => Stack.CurrentScreen is Editor);
+        }
+    }
+}

osu.Game/Screens/Edit/Components/Menus/DifficultyMenuItem.cs

@@ -10,9 +10,12 @@ namespace osu.Game.Screens.Edit.Components.Menus
 {
     public class DifficultyMenuItem : StatefulMenuItem<bool>
     {
+        public BeatmapInfo Beatmap { get; }
+
         public DifficultyMenuItem(BeatmapInfo beatmapInfo, bool selected, Action<BeatmapInfo> difficultyChangeFunc)
             : base(beatmapInfo.Version ?? "(unnamed)", null)
         {
+            Beatmap = beatmapInfo;
             State.Value = selected;
 
             if (!selected)