Add minimal implementation of gameplay testing from editor

osu.Game/Screens/Edit/Editor.cs

@@ -294,6 +294,7 @@ namespace osu.Game.Screens.Edit
                                                 RelativeSizeAxes = Axes.Both,
                                                 Padding = new MarginPadding { Left = 10 },
                                                 Size = new Vector2(1),
+                                                Action = testGameplay
                                             }
                                         },
                                     }
@@ -521,7 +522,21 @@ namespace osu.Game.Screens.Edit
             ApplyToBackground(b => b.FadeColour(Color4.White, 500));
             resetTrack();
 
-            // To update the game-wide beatmap with any changes, perform a re-fetch on exit.
+            refetchBeatmap();
+
+            return base.OnExiting(next);
+        }
+
+        public override void OnSuspending(IScreen next)
+        {
+            refetchBeatmap();
+
+            base.OnSuspending(next);
+        }
+
+        private void refetchBeatmap()
+        {
+            // To update the game-wide beatmap with any changes, perform a re-fetch on exit/suspend.
             // This is required as the editor makes its local changes via EditorBeatmap
             // (which are not propagated outwards to a potentially cached WorkingBeatmap).
             var refetchedBeatmap = beatmapManager.GetWorkingBeatmap(Beatmap.Value.BeatmapInfo);
@@ -531,8 +546,6 @@ namespace osu.Game.Screens.Edit
                 Logger.Log("Editor providing re-fetched beatmap post edit session");
                 Beatmap.Value = refetchedBeatmap;
             }
-
-            return base.OnExiting(next);
         }
 
         private void confirmExitWithSave()
@@ -763,6 +776,24 @@ namespace osu.Game.Screens.Edit
             loader?.CancelPendingDifficultySwitch();
         }
 
+        private void testGameplay()
+        {
+            if (HasUnsavedChanges)
+            {
+                dialogOverlay.Push(new SaveBeforeGameplayTestDialog(() =>
+                {
+                    Save();
+                    pushEditorPlayer();
+                }));
+            }
+            else
+            {
+                pushEditorPlayer();
+            }
+
+            void pushEditorPlayer() => this.Push(new PlayerLoader(() => new EditorPlayer()));
+        }
+
         public double SnapTime(double time, double? referenceTime) => editorBeatmap.SnapTime(time, referenceTime);
 
         public double GetBeatLengthAtTime(double referenceTime) => editorBeatmap.GetBeatLengthAtTime(referenceTime);

osu.Game/Screens/Edit/EditorPlayer.cs

@@ -0,0 +1,22 @@
+// 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 osu.Game.Screens.Play;
+
+namespace osu.Game.Screens.Edit
+{
+    public class EditorPlayer : Player
+    {
+        public EditorPlayer()
+            : base(new PlayerConfiguration { ShowResults = false })
+        {
+        }
+
+        protected override void PrepareReplay()
+        {
+            // don't record replays.
+        }
+
+        protected override bool CheckModsAllowFailure() => false; // never fail.
+    }
+}

osu.Game/Screens/Edit/SaveBeforeGameplayTestDialog.cs

@@ -0,0 +1,32 @@
+// 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 osu.Framework.Graphics.Sprites;
+using osu.Game.Overlays.Dialog;
+
+namespace osu.Game.Screens.Edit
+{
+    public class SaveBeforeGameplayTestDialog : PopupDialog
+    {
+        public SaveBeforeGameplayTestDialog(Action saveAndPreview)
+        {
+            HeaderText = "The beatmap will be saved in order to test it.";
+
+            Icon = FontAwesome.Regular.Save;
+
+            Buttons = new PopupDialogButton[]
+            {
+                new PopupDialogOkButton
+                {
+                    Text = "Sounds good, let's go!",
+                    Action = saveAndPreview
+                },
+                new PopupDialogCancelButton
+                {
+                    Text = "Oops, continue editing",
+                },
+            };
+        }
+    }
+}