Fix bugs and add test

osu.Game.Rulesets.Catch.Tests/TestSceneDrawableCatchRuleset.cs

@@ -0,0 +1,59 @@
+// 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 System.Linq;
+using NUnit.Framework;
+using osu.Framework.Logging;
+using osu.Framework.Testing;
+using osu.Game.Rulesets.Catch.Beatmaps;
+using osu.Game.Rulesets.Catch.Mods;
+using osu.Game.Rulesets.Catch.UI;
+using osu.Game.Rulesets.Mods;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Rulesets.Catch.Tests
+{
+    [TestFixture]
+    public class TestSceneDrawableCatchRulesetWithRelax : OsuTestScene
+    {
+        [SetUpSteps]
+        public void SetUpSteps()
+        {
+            AddStep("create drawable ruleset with relax mod", () =>
+            {
+                Child = new DrawableCatchRuleset(new CatchRuleset(), new CatchBeatmap(), new List<Mod>() {
+                    new CatchModRelax()
+                });
+            });
+            AddUntilStep("wait for load", () => Child.IsLoaded);
+        }
+
+        [Test]
+        public void TestBasic()
+        {
+            AddAssert("check if touch catcher is showing", () => this.ChildrenOfType<CatchTouchInputMapper>().Any() == false);
+        }
+    }
+
+    [TestFixture]
+    public class TestSceneDrawableCatchRulesetWithoutRelax : OsuTestScene
+    {
+        [SetUpSteps]
+        public void SetUpSteps()
+        {
+            AddStep("create drawable ruleset without relax mod", () =>
+            {
+                Child = new DrawableCatchRuleset(new CatchRuleset(), new CatchBeatmap(), new List<Mod>());
+            });
+            AddUntilStep("wait for load", () => Child.IsLoaded);
+            Logger.Log("Ready");
+        }
+
+        [Test]
+        public void TestBasic()
+        {
+            AddAssert("check if touch catcher is showing", () => this.ChildrenOfType<CatchTouchInputMapper>().Any());
+        }
+    }
+}

osu.Game.Rulesets.Catch/UI/DrawableCatchRuleset.cs

@@ -33,7 +33,7 @@ namespace osu.Game.Rulesets.Catch.UI
             : base(ruleset, beatmap, mods)
         {
             // Check if mods have RelaxMod instance
-            if (mods.OfType<ModRelax>().Any())
+            if (mods != null && mods.OfType<ModRelax>().Any())
                 showMobileMapper = false;
 
             Direction.Value = ScrollingDirection.Down;