Change to check for a particular spell rather than any spell

src/main/java/com/minelittlepony/unicopia/ability/PegasusRainboomAbility.java

@@ -5,7 +5,6 @@ import org.jetbrains.annotations.Nullable;
 import com.minelittlepony.unicopia.Race;
 import com.minelittlepony.unicopia.ability.data.Hit;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
-import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 import com.minelittlepony.unicopia.entity.player.Pony;
 import com.minelittlepony.unicopia.particle.MagicParticleEffect;
 import com.minelittlepony.unicopia.particle.OrientedBillboardParticleEffect;
@@ -41,7 +40,7 @@ public class PegasusRainboomAbility implements Ability<Hit> {
             return null;
         }
 
-        if (player.getPhysics().isFlying() && !player.getSpellSlot().isPresent()) {
+        if (player.getPhysics().isFlying() && !SpellType.RAINBOOM.isOn(player)) {
             return Hit.INSTANCE;
         }
 
@@ -65,7 +64,7 @@ public class PegasusRainboomAbility implements Ability<Hit> {
             return;
         }
 
-        if (player.getPhysics().isFlying() && !player.getSpellSlot().isPresent()) {
+        if (player.getPhysics().isFlying() && !SpellType.RAINBOOM.isOn(player)) {
             player.getMagicalReserves().getMana().multiply(0.1F);
             player.addParticle(new OrientedBillboardParticleEffect(UParticles.RAINBOOM_RING, player.getPhysics().getMotionAngle()), player.getOriginVector(), Vec3d.ZERO);
             SpellType.RAINBOOM.withTraits().apply(player);

src/main/java/com/minelittlepony/unicopia/ability/magic/SpellContainer.java

@@ -43,6 +43,13 @@ public interface SpellContainer {
      */
     boolean contains(UUID id);
 
+    /**
+     * Checks if any matching spells are active.
+     */
+    default boolean contains(@Nullable SpellPredicate<?> type) {
+        return get(type, true).isPresent();
+    }
+
     /**
      * Gets the active effect for this caster updating it if needed.
      */
@@ -52,9 +59,12 @@ public interface SpellContainer {
 
     /**
      * Returns true if this caster has an active effect attached to it.
+     *
+     * @deprecated To be removed
      */
+    @Deprecated
     default boolean isPresent() {
-        return get(true).isPresent();
+        return contains((SpellPredicate<?>)null);
     }
 
     /**
@@ -95,6 +105,11 @@ public interface SpellContainer {
             return delegate().contains(id);
         }
 
+        @Override
+        default boolean contains(@Nullable SpellPredicate<?> type) {
+            return delegate().contains(type);
+        }
+
         @Override
         default <T extends Spell> Optional<T> get(@Nullable SpellPredicate<T> type, boolean update) {
             return delegate().get(type, update);

src/main/java/com/minelittlepony/unicopia/ability/magic/SpellPredicate.java

@@ -14,6 +14,6 @@ public interface SpellPredicate<T extends Spell> extends Predicate<Spell> {
     SpellPredicate<AbstractDisguiseSpell> IS_DISGUISE = s -> s instanceof AbstractDisguiseSpell;
 
     default boolean isOn(Caster<?> caster) {
-        return caster.getSpellSlot().get(this, false).isPresent();
+        return caster.getSpellSlot().contains(this);
     }
 }

src/main/java/com/minelittlepony/unicopia/entity/player/Pony.java

@@ -16,6 +16,7 @@ import com.minelittlepony.unicopia.WorldTribeManager;
 import com.minelittlepony.unicopia.ability.AbilityDispatcher;
 import com.minelittlepony.unicopia.ability.EarthPonyStompAbility;
 import com.minelittlepony.unicopia.ability.magic.Affine;
+import com.minelittlepony.unicopia.ability.magic.SpellPredicate;
 import com.minelittlepony.unicopia.ability.magic.spell.Spell;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.TraitDiscovery;
@@ -161,7 +162,7 @@ public class Pony extends Living<PlayerEntity> implements Transmittable, Copieab
 
     @Override
     public boolean isInvisible() {
-        return invisible && getSpellSlot().isPresent();
+        return invisible && SpellPredicate.IS_DISGUISE.isOn(this);
     }
 
     public boolean isSpeciesPersisted() {

src/main/java/com/minelittlepony/unicopia/network/datasync/EffectSync.java

@@ -46,14 +46,14 @@ public class EffectSync implements SpellContainer {
     }
 
     @Override
-    @SuppressWarnings("unchecked")
-    public <T extends Spell> Optional<T> get(@Nullable SpellPredicate<T> type, boolean update) {
-        return (Optional<T>)(type == null ? read(update, true).findFirst() : read(update, true).filter(type).findFirst());
+    public boolean contains(@Nullable SpellPredicate<?> type) {
+        return read(type, true, false).findFirst().isPresent();
     }
 
     @Override
-    public boolean isPresent() {
-        return read(true, false).findFirst().isPresent();
+    @SuppressWarnings("unchecked")
+    public <T extends Spell> Optional<T> get(@Nullable SpellPredicate<T> type, boolean update) {
+        return (Optional<T>)(read(type, update, true).findFirst());
     }
 
     @Override
@@ -99,12 +99,15 @@ public class EffectSync implements SpellContainer {
         }
     }
 
-    private Stream<Spell> read(boolean synchronize, boolean sendUpdate) {
+    private Stream<Spell> read(@Nullable SpellPredicate<?> type, boolean synchronize, boolean sendUpdate) {
         if (synchronize && spells.fromNbt(owner.getEntity().getDataTracker().get(param)) && sendUpdate) {
             owner.getEntity().getDataTracker().set(param, spells.toNbt());
         }
 
-        return spells.getReferences();
+        if (type == null) {
+            return spells.getReferences();
+        }
+        return spells.getReferences().filter(type);
     }
 
     public boolean reduce(Alteration alteration) {