Fire the MOB_CONVERSION event after shearing the mushroom cow (#3612)

* Fire the MOB_CONVERSION event after shearing the mushroom cow

* checkstyle

* Add license header

fabric-entity-events-v1/src/main/java/net/fabricmc/fabric/mixin/entity/event/MooshroomEntityMixin.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2016, 2017, 2018, 2019 FabricMC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.fabricmc.fabric.mixin.entity.event;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.ModifyArg;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.mob.MobEntity;
+import net.minecraft.entity.passive.MooshroomEntity;
+
+import net.fabricmc.fabric.api.entity.event.v1.ServerLivingEntityEvents;
+
+@Mixin(MooshroomEntity.class)
+class MooshroomEntityMixin {
+	@ModifyArg(
+			method = "sheared",
+			at = @At(ordinal = 0, value = "INVOKE", target = "Lnet/minecraft/world/World;spawnEntity(Lnet/minecraft/entity/Entity;)Z")
+	)
+	private Entity afterMooshroomConversion(Entity converted) {
+		ServerLivingEntityEvents.MOB_CONVERSION.invoker().onConversion((MooshroomEntity) (Object) this, (MobEntity) converted, false);
+		return converted;
+	}
+}

fabric-entity-events-v1/src/main/resources/fabric-entity-events-v1.mixins.json

@@ -6,6 +6,7 @@
     "EntityMixin",
     "LivingEntityMixin",
     "MobEntityMixin",
+    "MooshroomEntityMixin",
     "PigEntityMixin",
     "PlayerEntityMixin",
     "PlayerManagerMixin",