Add drops to shear events (#5678)

2024-11-15 04:20:04 +01:00 · 2023-12-28 14:41:07 -08:00 · 2023-12-28 14:41:07 -08:00 · 2c3ccb80f0
Commit 2c3ccb80f0
--- a/patches/api/0454-Add-drops-to-shear-events.patch
+++ b/patches/api/0454-Add-drops-to-shear-events.patch
@ -0,0 +1,103 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jake Potrebic <jake.m.potrebic@gmail.com>
+Date: Tue, 18 May 2021 12:31:54 -0700
+Subject: [PATCH] Add drops to shear events
+
+
+diff --git a/src/main/java/org/bukkit/event/block/BlockShearEntityEvent.java b/src/main/java/org/bukkit/event/block/BlockShearEntityEvent.java
+index 71c0af9373069cfaa074e1fbad592eab81025b1c..610768bd329b8612627d361fd9a773a7b91ff108 100644
+--- a/src/main/java/org/bukkit/event/block/BlockShearEntityEvent.java
+++ b/src/main/java/org/bukkit/event/block/BlockShearEntityEvent.java
+@@ -17,11 +17,14 @@ public class BlockShearEntityEvent extends BlockEvent implements Cancellable {
+     private final Entity sheared;
+     private final ItemStack tool;
+     private boolean cancelled;
+    private java.util.List<ItemStack> drops; // Paper
+ 
+-    public BlockShearEntityEvent(@NotNull Block dispenser, @NotNull Entity sheared, @NotNull ItemStack tool) {
+    @org.jetbrains.annotations.ApiStatus.Internal // Paper
+    public BlockShearEntityEvent(@NotNull Block dispenser, @NotNull Entity sheared, @NotNull ItemStack tool, final @NotNull java.util.List<ItemStack> drops) { // Paper - custom shear drops
+         super(dispenser);
+         this.sheared = sheared;
+         this.tool = tool;
+        this.drops = drops; // Paper
+     }
+ 
+     /**
+@@ -64,4 +67,24 @@ public class BlockShearEntityEvent extends BlockEvent implements Cancellable {
+     public static HandlerList getHandlerList() {
+         return handlers;
+     }
+    // Paper start - custom shear drops
+    /**
+     * Get an immutable list of drops for this shearing.
+     *
+     * @return the shearing drops
+     * @see #setDrops(java.util.List)
+     */
+    public java.util.@NotNull @org.jetbrains.annotations.Unmodifiable List<ItemStack> getDrops() {
+        return java.util.Collections.unmodifiableList(this.drops);
+    }
+
+    /**
+     * Sets the drops for the shearing.
+     *
+     * @param drops the shear drops
+     */
+    public void setDrops(final java.util.@NotNull List<org.bukkit.inventory.ItemStack> drops) {
+        this.drops = java.util.List.copyOf(drops);
+    }
+    // Paper end - custom shear drops
+ }
+diff --git a/src/main/java/org/bukkit/event/player/PlayerShearEntityEvent.java b/src/main/java/org/bukkit/event/player/PlayerShearEntityEvent.java
+index 04b3dce008edefb045162d0f69f87462ea1f3534..63f6799c2543ba67ce9fe6484002062d7a754fd0 100644
+--- a/src/main/java/org/bukkit/event/player/PlayerShearEntityEvent.java
+++ b/src/main/java/org/bukkit/event/player/PlayerShearEntityEvent.java
+@@ -18,17 +18,20 @@ public class PlayerShearEntityEvent extends PlayerEvent implements Cancellable {
+     private final Entity what;
+     private final ItemStack item;
+     private final EquipmentSlot hand;
+    private java.util.List<ItemStack> drops; // Paper - custom shear drops
+ 
+-    public PlayerShearEntityEvent(@NotNull Player who, @NotNull Entity what, @NotNull ItemStack item, @NotNull EquipmentSlot hand) {
+    @org.jetbrains.annotations.ApiStatus.Internal // Paper
+    public PlayerShearEntityEvent(@NotNull Player who, @NotNull Entity what, @NotNull ItemStack item, @NotNull EquipmentSlot hand, final java.util.@NotNull List<ItemStack> drops) { // Paper - custom shear drops
+         super(who);
+         this.what = what;
+         this.item = item;
+         this.hand = hand;
+        this.drops = drops; // Paper - custom shear drops
+     }
+ 
+     @Deprecated
+     public PlayerShearEntityEvent(@NotNull final Player who, @NotNull final Entity what) {
+-        this(who, what, new ItemStack(Material.SHEARS), EquipmentSlot.HAND);
+        this(who, what, new ItemStack(Material.SHEARS), EquipmentSlot.HAND, java.util.Collections.emptyList()); // Paper - custom shear drops
+     }
+ 
+     @Override
+@@ -82,4 +85,24 @@ public class PlayerShearEntityEvent extends PlayerEvent implements Cancellable {
+         return handlers;
+     }
+ 
+    // Paper start - custom shear drops
+    /**
+     * Get an immutable list of drops for this shearing.
+     *
+     * @return the shearing drops
+     * @see #setDrops(java.util.List)
+     */
+    public java.util.@NotNull @org.jetbrains.annotations.Unmodifiable List<ItemStack> getDrops() {
+        return this.drops;
+    }
+
+    /**
+     * Sets the drops for the shearing.
+     *
+     * @param drops the shear drops
+     */
+    public void setDrops(final java.util.@NotNull List<org.bukkit.inventory.ItemStack> drops) {
+        this.drops = java.util.List.copyOf(drops);
+    }
+    // Paper end - custom shear drops
+ }
--- a/patches/server/1055-Add-drops-to-shear-events.patch
+++ b/patches/server/1055-Add-drops-to-shear-events.patch
@ -0,0 +1,325 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jake Potrebic <jake.m.potrebic@gmail.com>
+Date: Tue, 18 May 2021 12:32:02 -0700
+Subject: [PATCH] Add drops to shear events
+
+
+diff --git a/src/main/java/net/minecraft/core/dispenser/ShearsDispenseItemBehavior.java b/src/main/java/net/minecraft/core/dispenser/ShearsDispenseItemBehavior.java
+index e17090003988ad2c890d48666c2234b14d511345..ec43e8294d7e7112478a2fc1475f0852690a4882 100644
+--- a/src/main/java/net/minecraft/core/dispenser/ShearsDispenseItemBehavior.java
+++ b/src/main/java/net/minecraft/core/dispenser/ShearsDispenseItemBehavior.java
+@@ -103,11 +103,14 @@ public class ShearsDispenseItemBehavior extends OptionalDispenseItemBehavior {
+ 
+                 if (ishearable.readyForShearing()) {
+                     // CraftBukkit start
+-                    if (CraftEventFactory.callBlockShearEntityEvent(entityliving, bukkitBlock, craftItem).isCancelled()) {
+                    // Paper start
+                    org.bukkit.event.block.BlockShearEntityEvent event = CraftEventFactory.callBlockShearEntityEvent(entityliving, bukkitBlock, craftItem, ishearable.generateDefaultDrops());
+                    if (event.isCancelled()) {
+                        // Paper end
+                         continue;
+                     }
+                     // CraftBukkit end
+-                    ishearable.shear(SoundSource.BLOCKS);
+                    ishearable.shear(SoundSource.BLOCKS, CraftItemStack.asNMSCopy(event.getDrops())); // Paper
+                     worldserver.gameEvent((Entity) null, GameEvent.SHEAR, blockposition);
+                     return true;
+                 }
+diff --git a/src/main/java/net/minecraft/world/entity/Shearable.java b/src/main/java/net/minecraft/world/entity/Shearable.java
+index 5e8cc5cfac8888628c6d513148f41be09ca65a2c..4921d1b2ff9112374477c5c9b4a68cc75a51dbf8 100644
+--- a/src/main/java/net/minecraft/world/entity/Shearable.java
+++ b/src/main/java/net/minecraft/world/entity/Shearable.java
+@@ -3,7 +3,13 @@ package net.minecraft.world.entity;
+ import net.minecraft.sounds.SoundSource;
+ 
+ public interface Shearable {
+    default void shear(SoundSource soundCategory, java.util.List<net.minecraft.world.item.ItemStack> drops) { this.shear(soundCategory); } // Paper
+     void shear(SoundSource shearedSoundCategory);
+ 
+     boolean readyForShearing();
+    // Paper start - ensure all implementing entities override this
+    default java.util.List<net.minecraft.world.item.ItemStack> generateDefaultDrops() {
+        return java.util.Collections.emptyList();
+    }
+    // Paper end
+ }
+diff --git a/src/main/java/net/minecraft/world/entity/animal/MushroomCow.java b/src/main/java/net/minecraft/world/entity/animal/MushroomCow.java
+index e42b0b19019ef74733fd19b08f882cccff920142..a7e8b544d7b05efe95182a03cabaf1993da9d839 100644
+--- a/src/main/java/net/minecraft/world/entity/animal/MushroomCow.java
+++ b/src/main/java/net/minecraft/world/entity/animal/MushroomCow.java
+@@ -122,11 +122,18 @@ public class MushroomCow extends Cow implements Shearable, VariantHolder<Mushroo
+             return InteractionResult.sidedSuccess(this.level().isClientSide);
+         } else if (itemstack.is(Items.SHEARS) && this.readyForShearing()) {
+             // CraftBukkit start
+-            if (!CraftEventFactory.handlePlayerShearEntityEvent(player, this, itemstack, hand)) {
+-                return InteractionResult.PASS;
+            // Paper start - custom shear drops
+            List<ItemStack> drops = this.generateDefaultDrops();
+            org.bukkit.event.player.PlayerShearEntityEvent event = CraftEventFactory.handlePlayerShearEntityEvent(player, this, itemstack, hand, drops);
+            if (event != null) {
+                if (event.isCancelled()) {
+                    return InteractionResult.PASS;
+                }
+                drops = org.bukkit.craftbukkit.inventory.CraftItemStack.asNMSCopy(event.getDrops());
+             }
+            // Paper end - custom shear drops
+             // CraftBukkit end
+-            this.shear(SoundSource.PLAYERS);
+            this.shear(SoundSource.PLAYERS, drops); // Paper
+             this.gameEvent(GameEvent.SHEAR, player);
+             if (!this.level().isClientSide) {
+                 itemstack.hurtAndBreak(1, player, (entityhuman1) -> {
+@@ -167,6 +174,22 @@ public class MushroomCow extends Cow implements Shearable, VariantHolder<Mushroo
+ 
+     @Override
+     public void shear(SoundSource shearedSoundCategory) {
+        // Paper start - custom shear drops
+        this.shear(shearedSoundCategory, this.generateDefaultDrops());
+    }
+
+    @Override
+    public List<ItemStack> generateDefaultDrops() {
+        List<ItemStack> dropEntities = new java.util.ArrayList<>(5);
+        for (int i = 0; i < 5; ++i) {
+            dropEntities.add(new ItemStack(this.getVariant().getBlockState().getBlock()));
+        }
+        return dropEntities;
+    }
+
+    @Override
+    public void shear(SoundSource shearedSoundCategory, List<ItemStack> drops) { // If drops is null, need to generate drops
+        // Paper end - custom shear drops
+         this.level().playSound((Player) null, (Entity) this, SoundEvents.MOOSHROOM_SHEAR, shearedSoundCategory, 1.0F, 1.0F);
+         if (!this.level().isClientSide()) {
+             Cow entitycow = (Cow) EntityType.COW.create(this.level());
+@@ -196,17 +219,12 @@ public class MushroomCow extends Cow implements Shearable, VariantHolder<Mushroo
+                 this.discard(); // CraftBukkit - from above
+                 // CraftBukkit end
+ 
+-                for (int i = 0; i < 5; ++i) {
+-                    // CraftBukkit start
+-                    ItemEntity entityitem = new ItemEntity(this.level(), this.getX(), this.getY(1.0D), this.getZ(), new ItemStack(this.getVariant().blockState.getBlock()));
+-                    EntityDropItemEvent event = new EntityDropItemEvent(this.getBukkitEntity(), (org.bukkit.entity.Item) entityitem.getBukkitEntity());
+-                    Bukkit.getPluginManager().callEvent(event);
+-                    if (event.isCancelled()) {
+-                        continue;
+-                    }
+-                    this.level().addFreshEntity(entityitem);
+-                    // CraftBukkit end
+                // Paper start - custom shear drops (moved drop generation to separate method)
+                for (final ItemStack drop : drops) {
+                    ItemEntity entityitem = new ItemEntity(this.level(), this.getX(), this.getY(1.0D), this.getZ(), drop);
+                    this.spawnAtLocation(entityitem);
+                 }
+                // Paper end - custom shear drops
+             }
+         }
+ 
+diff --git a/src/main/java/net/minecraft/world/entity/animal/Sheep.java b/src/main/java/net/minecraft/world/entity/animal/Sheep.java
+index 55afa58f3df53ce548c7484d8fff62c903f9dc07..1d80678f7e8f658e43616f0baf723f096a99122a 100644
+--- a/src/main/java/net/minecraft/world/entity/animal/Sheep.java
+++ b/src/main/java/net/minecraft/world/entity/animal/Sheep.java
+@@ -253,11 +253,18 @@ public class Sheep extends Animal implements Shearable {
+         if (itemstack.is(Items.SHEARS)) {
+             if (!this.level().isClientSide && this.readyForShearing()) {
+                 // CraftBukkit start
+-                if (!CraftEventFactory.handlePlayerShearEntityEvent(player, this, itemstack, hand)) {
+-                    return InteractionResult.PASS;
+                // Paper start - custom shear drops
+                java.util.List<ItemStack> drops = this.generateDefaultDrops();
+                org.bukkit.event.player.PlayerShearEntityEvent event = CraftEventFactory.handlePlayerShearEntityEvent(player, this, itemstack, hand, drops);
+                if (event != null) {
+                    if (event.isCancelled()) {
+                        return InteractionResult.PASS;
+                    }
+                    drops = org.bukkit.craftbukkit.inventory.CraftItemStack.asNMSCopy(event.getDrops());
+                 }
+                // Paper end - custom shear drops
+                 // CraftBukkit end
+-                this.shear(SoundSource.PLAYERS);
+                this.shear(SoundSource.PLAYERS, drops); // Paper
+                 this.gameEvent(GameEvent.SHEAR, player);
+                 itemstack.hurtAndBreak(1, player, (entityhuman1) -> {
+                     entityhuman1.broadcastBreakEvent(hand);
+@@ -273,13 +280,30 @@ public class Sheep extends Animal implements Shearable {
+ 
+     @Override
+     public void shear(SoundSource shearedSoundCategory) {
+        // Paper start - custom shear drops
+        this.shear(shearedSoundCategory, this.generateDefaultDrops());
+    }
+
+    @Override
+    public java.util.List<ItemStack> generateDefaultDrops() {
+        int count = 1 + this.random.nextInt(3);
+        java.util.List<ItemStack> dropEntities = new java.util.ArrayList<>(count);
+        for (int j = 0; j < count; ++j) {
+            dropEntities.add(new ItemStack(Sheep.ITEM_BY_DYE.get(this.getColor())));
+        }
+        return dropEntities;
+    }
+
+    @Override
+    public void shear(SoundSource shearedSoundCategory, java.util.List<ItemStack> drops) {
+        // Paper end - custom shear drops
+         this.level().playSound((Player) null, (Entity) this, SoundEvents.SHEEP_SHEAR, shearedSoundCategory, 1.0F, 1.0F);
+         this.setSheared(true);
+         int i = 1 + this.random.nextInt(3);
+ 
+-        for (int j = 0; j < i; ++j) {
+        for (final ItemStack drop : drops) { // Paper - custom shear drops (moved drop generation to separate method)
+             this.forceDrops = true; // CraftBukkit
+-            ItemEntity entityitem = this.spawnAtLocation((ItemLike) Sheep.ITEM_BY_DYE.get(this.getColor()), 1);
+            ItemEntity entityitem = this.spawnAtLocation(drop, 1); // Paper - custom shear drops
+             this.forceDrops = false; // CraftBukkit
+ 
+             if (entityitem != null) {
+diff --git a/src/main/java/net/minecraft/world/entity/animal/SnowGolem.java b/src/main/java/net/minecraft/world/entity/animal/SnowGolem.java
+index 8adcfc8f6772a32b5915e4a07100e8eb735f907a..b5d6857eaf2bed14adcb5f5e80d91b44eb8b0dcc 100644
+--- a/src/main/java/net/minecraft/world/entity/animal/SnowGolem.java
+++ b/src/main/java/net/minecraft/world/entity/animal/SnowGolem.java
+@@ -153,11 +153,18 @@ public class SnowGolem extends AbstractGolem implements Shearable, RangedAttackM
+ 
+         if (itemstack.is(Items.SHEARS) && this.readyForShearing()) {
+             // CraftBukkit start
+-            if (!CraftEventFactory.handlePlayerShearEntityEvent(player, this, itemstack, hand)) {
+-                return InteractionResult.PASS;
+            // Paper start - custom shear drops
+            java.util.List<ItemStack> drops = this.generateDefaultDrops();
+            org.bukkit.event.player.PlayerShearEntityEvent event = CraftEventFactory.handlePlayerShearEntityEvent(player, this, itemstack, hand, drops);
+            if (event != null) {
+                if (event.isCancelled()) {
+                    return InteractionResult.PASS;
+                }
+                drops = org.bukkit.craftbukkit.inventory.CraftItemStack.asNMSCopy(event.getDrops());
+             }
+            // Paper end - custom shear drops
+             // CraftBukkit end
+-            this.shear(SoundSource.PLAYERS);
+            this.shear(SoundSource.PLAYERS, drops); // Paper
+             this.gameEvent(GameEvent.SHEAR, player);
+             if (!this.level().isClientSide) {
+                 itemstack.hurtAndBreak(1, player, (entityhuman1) -> {
+@@ -173,12 +180,28 @@ public class SnowGolem extends AbstractGolem implements Shearable, RangedAttackM
+ 
+     @Override
+     public void shear(SoundSource shearedSoundCategory) {
+        // Paper start - custom shear drops
+        this.shear(shearedSoundCategory, this.generateDefaultDrops());
+    }
+
+    @Override
+    public java.util.List<ItemStack> generateDefaultDrops() {
+        return java.util.Collections.singletonList(new ItemStack(Items.CARVED_PUMPKIN));
+    }
+
+    @Override
+    public void shear(SoundSource shearedSoundCategory, java.util.List<ItemStack> drops) {
+        // Paper end - custom shear drops
+         this.level().playSound((Player) null, (Entity) this, SoundEvents.SNOW_GOLEM_SHEAR, shearedSoundCategory, 1.0F, 1.0F);
+         if (!this.level().isClientSide()) {
+             this.setPumpkin(false);
+-            this.forceDrops = true; // CraftBukkit
+-            this.spawnAtLocation(new ItemStack(Items.CARVED_PUMPKIN), 1.7F);
+-            this.forceDrops = false; // CraftBukkit
+            // Paper start - custom shear drops (moved drop generation to separate method)
+            for (final ItemStack drop : drops) {
+                this.forceDrops = true;
+                this.spawnAtLocation(drop, 1.7F);
+                this.forceDrops = false;
+            }
+            // Paper end - custom shear drops
+         }
+ 
+     }
+diff --git a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+index f67ec3f5f4b7e2f678609f2387cc8afa2adce161..a36ffbbab5bbfec5a4a224dc5ee8812b98dd4d7c 100644
+--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+@@ -1718,20 +1718,20 @@ public class CraftEventFactory {
+         return event;
+     }
+ 
+-    public static BlockShearEntityEvent callBlockShearEntityEvent(Entity animal, org.bukkit.block.Block dispenser, CraftItemStack is) {
+-        BlockShearEntityEvent bse = new BlockShearEntityEvent(dispenser, animal.getBukkitEntity(), is);
+    public static BlockShearEntityEvent callBlockShearEntityEvent(Entity animal, Block dispenser, CraftItemStack is, List<ItemStack> drops) { // Paper - custom shear drops
+        BlockShearEntityEvent bse = new BlockShearEntityEvent(dispenser, animal.getBukkitEntity(), is, Lists.transform(drops, CraftItemStack::asCraftMirror)); // Paper - custom shear drops
+         Bukkit.getPluginManager().callEvent(bse);
+         return bse;
+     }
+ 
+-    public static boolean handlePlayerShearEntityEvent(net.minecraft.world.entity.player.Player player, Entity sheared, ItemStack shears, InteractionHand hand) {
+    public static PlayerShearEntityEvent handlePlayerShearEntityEvent(net.minecraft.world.entity.player.Player player, Entity sheared, ItemStack shears, InteractionHand hand, List<ItemStack> drops) { // Paper - custom shear drops
+         if (!(player instanceof ServerPlayer)) {
+-            return true;
+            return null; // Paper - custom shear drops
+         }
+ 
+-        PlayerShearEntityEvent event = new PlayerShearEntityEvent((Player) player.getBukkitEntity(), sheared.getBukkitEntity(), CraftItemStack.asCraftMirror(shears), (hand == InteractionHand.OFF_HAND ? EquipmentSlot.OFF_HAND : EquipmentSlot.HAND));
+        PlayerShearEntityEvent event = new PlayerShearEntityEvent((Player) player.getBukkitEntity(), sheared.getBukkitEntity(), CraftItemStack.asCraftMirror(shears), (hand == InteractionHand.OFF_HAND ? EquipmentSlot.OFF_HAND : EquipmentSlot.HAND), Lists.transform(drops, CraftItemStack::asCraftMirror)); // Paper - custom shear drops
+         Bukkit.getPluginManager().callEvent(event);
+-        return !event.isCancelled();
+        return event; // Paper - custom shear drops
+     }
+ 
+     public static Cancellable handleStatisticsIncrease(net.minecraft.world.entity.player.Player entityHuman, net.minecraft.stats.Stat<?> statistic, int current, int newValue) {
+diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
+index 32da455eb46d09a846bae5270b32a6d6d6b962fd..c1d902c8dd2ec23240ee60ca9e9eaf7c839baed5 100644
+--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
+++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
+@@ -61,6 +61,15 @@ public final class CraftItemStack extends ItemStack {
+         }
+         return stack;
+     }
+    // Paper start
+    public static java.util.List<net.minecraft.world.item.ItemStack> asNMSCopy(java.util.List<? extends ItemStack> originals) {
+        final java.util.List<net.minecraft.world.item.ItemStack> nms = new java.util.ArrayList<>();
+        for (final org.bukkit.inventory.ItemStack original : originals) {
+            nms.add(asNMSCopy(original));
+        }
+        return nms;
+    }
+    // Paper end
+ 
+     public static net.minecraft.world.item.ItemStack copyNMSStack(net.minecraft.world.item.ItemStack original, int amount) {
+         net.minecraft.world.item.ItemStack stack = original.copy();
+diff --git a/src/test/java/io/papermc/paper/entity/ShearableDropsTest.java b/src/test/java/io/papermc/paper/entity/ShearableDropsTest.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..e612515f7709dbe5d1fa5751337cdc34fce10a98
+--- /dev/null
+++ b/src/test/java/io/papermc/paper/entity/ShearableDropsTest.java
+@@ -0,0 +1,34 @@
+package io.papermc.paper.entity;
+
+import io.github.classgraph.ClassGraph;
+import io.github.classgraph.ClassInfo;
+import io.github.classgraph.MethodInfoList;
+import io.github.classgraph.ScanResult;
+import java.util.ArrayList;
+import net.minecraft.world.entity.Shearable;
+import org.bukkit.support.AbstractTestingBase;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ShearableDropsTest extends AbstractTestingBase {
+
+    static Iterable<ClassInfo> parameters() {
+        try (ScanResult scanResult = new ClassGraph()
+            .enableClassInfo()
+            .enableMethodInfo()
+            .whitelistPackages("net.minecraft")
+            .scan()
+        ) {
+            return new ArrayList<>(scanResult.getClassesImplementing(Shearable.class.getName()));
+        }
+    }
+
+    @ParameterizedTest
+    @MethodSource("parameters")
+    void checkShearableDropOverrides(final ClassInfo classInfo) {
+        final MethodInfoList generateDefaultDrops = classInfo.getDeclaredMethodInfo("generateDefaultDrops");
+        assertEquals(1, generateDefaultDrops.size(), classInfo.getName() + " doesn't implement Shearable#generateDefaultDrops");
+    }
+}