Fix synesthesia divisor mode only considering slides

osu.Game.Rulesets.Sentakki.Tests/Mods/TestSceneModSynesthesia.cs

@@ -0,0 +1,32 @@
+using NUnit.Framework;
+using osu.Game.Rulesets.Sentakki.Mods;
+using osu.Game.Tests.Visual;
+
+namespace osu.Game.Rulesets.Sentakki.Tests.Mods;
+
+public partial class TestSceneModSynesthesia : ModTestScene
+{
+    protected override Ruleset CreatePlayerRuleset() => new SentakkiRuleset();
+
+    [Test]
+    public void TestDivisorMode() => CreateModTest(new ModTestData
+    {
+        Mod = new SentakkiModSynesthesia()
+        {
+            IntervalColouring = { Value = false }
+        },
+        Autoplay = true,
+        PassCondition = () => true
+    });
+
+    [Test]
+    public void TestIntervalMode() => CreateModTest(new ModTestData
+    {
+        Mod = new SentakkiModSynesthesia()
+        {
+            IntervalColouring = { Value = true }
+        },
+        Autoplay = true,
+        PassCondition = () => true
+    });
+}

osu.Game.Rulesets.Sentakki/Mods/SentakkiModSynesthesia.cs

@@ -38,6 +38,7 @@ private static void applyDivisorBasedNoteColouring(SentakkiBeatmap beatmap)
         OsuColour colours = new OsuColour();
 
         var hitobjects = beatmap.HitObjects.Where(h => h is Slide).SelectMany(s => s.NestedHitObjects).Cast<SentakkiHitObject>().ToList();
+        hitobjects.AddRange(beatmap.HitObjects);
 
         foreach (var hitObject in hitobjects)
         {