[WIP] Multiplayer Mods Regression Test

osu.Game.Tests/Visual/Multiplayer/TestMultiplayerModLoading.cs

@@ -0,0 +1,52 @@
+// 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 NUnit.Framework;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.Osu.Mods;
+using osu.Game.Screens.Select;
+
+// Resolve these names to types because there is a Namespace called "Playlists" and "Multiplayer" which conflicts
+using MultiplayerScreenAlias = osu.Game.Screens.OnlinePlay.Multiplayer.Multiplayer;
+using PlaylistsScreenAlias = osu.Game.Screens.OnlinePlay.Playlists.Playlists;
+
+namespace osu.Game.Tests.Visual.Multiplayer
+{
+    public class TestMultiplayerModLoading : OsuGameTestScene
+    {
+
+        [SetUp]
+        public void SetUp() => Schedule(() =>
+        {
+            SelectedMods.Value = Array.Empty<Mod>();
+        });
+
+
+        /// <summary>
+        /// This is a regression test that tests whether a singleplayer mod can transfer over to a multiplayer screen.
+        /// It should not carry over from these screens, prevents regression on https://github.com/ppy/osu/pull/17352 
+        /// </summary>
+        [Test]
+        public void TestSingleplayerModsDontCarryToMultiplayerScreens()
+        {
+            PushAndConfirm(() => new PlaySongSelect());
+
+            // Select Mods while a "singleplayer" screen is active
+            var osuAutomationMod = new OsuModAutoplay();
+            var expectedMods = new[] { osuAutomationMod };
+
+            AddStep("Toggle on the automation Mod.", () => { SelectedMods.Value = expectedMods; });
+            AddAssert("", () => SelectedMods.Value == expectedMods);
+
+            PushAndConfirm(() => new TestMultiplayerComponents());
+            AddAssert("Mods are Empty After A Multiplayer Screen Loads", () => SelectedMods.Value.Count == 0);
+
+            AddStep("Retoggle on the automation Mod.", () => { SelectedMods.Value = expectedMods; });
+            AddAssert("", () => SelectedMods.Value == expectedMods);
+
+            // TODO: Implement TestPlaylistComponents? 
+            //PushAndConfirm(() => new TestPlaylistComponents());
+            //AddAssert("Mods are Empty After Playlist Screen Loads", () => !SelectedMods.Value.Any());
+        }
+    }
+}