Improve entity effect API

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java

@@ -1291,4 +1291,15 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
         return this.getHandle().getScoreboardName();
     }
     // Paper end - entity scoreboard name
+
+    // Paper start - broadcast hurt animation
+    @Override
+    public void broadcastHurtAnimation(java.util.Collection<Player> players) {
+        //noinspection SuspiciousMethodCalls
+        Preconditions.checkArgument(!players.contains(this), "Cannot broadcast hurt animation to self without a yaw");
+        for (final org.bukkit.entity.Player player : players) {
+            ((CraftPlayer) player).sendHurtAnimation(0, this);
+        }
+    }
+    // Paper end - broadcast hurt animation
 }

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java

@@ -1284,6 +1284,11 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void sendHurtAnimation(float yaw) {
+        // Paper start - Add target entity to sendHurtAnimation
+        this.sendHurtAnimation(yaw, this);
+    }
+    public void sendHurtAnimation(float yaw, org.bukkit.entity.Entity target) {
+        // Paper end - Add target entity to sendHurtAnimation
         if (this.getHandle().connection == null) {
             return;
         }
@@ -1293,7 +1298,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
          * This makes no sense. We'll add 90 to it so that 0 = front, clockwise from there.
          */
         float actualYaw = yaw + 90;
-        this.getHandle().connection.send(new ClientboundHurtAnimationPacket(this.getEntityId(), actualYaw));
+        this.getHandle().connection.send(new ClientboundHurtAnimationPacket(target.getEntityId(), actualYaw)); // Paper - Add target entity to sendHurtAnimation
     }
 
     @Override
@@ -3515,4 +3520,14 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
     public void setSendViewDistance(final int viewDistance) {
         throw new UnsupportedOperationException("Not implemented yet");
     }
+
+    // Paper start - entity effect API
+    @Override
+    public void sendEntityEffect(final org.bukkit.EntityEffect effect, final org.bukkit.entity.Entity target) {
+        if (this.getHandle().connection == null || !effect.isApplicableTo(target)) {
+            return;
+        }
+        this.getHandle().connection.send(new net.minecraft.network.protocol.game.ClientboundEntityEventPacket(((CraftEntity) target).getHandle(), effect.getData()));
+    }
+    // Paper end - entity effect API
 }

paper-server/src/test/java/org/bukkit/EntityEffectTest.java

@@ -0,0 +1,82 @@
+package org.bukkit;
+
+import com.google.common.base.Joiner;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import net.minecraft.world.entity.EntityEvent;
+import org.bukkit.support.environment.Normal;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.fail;
+
+@Normal
+public class EntityEffectTest {
+
+    private static List<Byte> collectNmsLevelEvents() throws ReflectiveOperationException {
+        final List<Byte> events = new ArrayList<>();
+        for (final Field field : EntityEvent.class.getFields()) {
+            if (Modifier.isStatic(field.getModifiers()) && Modifier.isFinal(field.getModifiers()) && field.getType() == byte.class) {
+                events.add((byte) field.get(null));
+            }
+        }
+        for (int i = 22; i <= 28; i++) {
+            events.remove(Byte.valueOf((byte) i)); // all have existing API (debug info and op level)
+        }
+        events.remove(Byte.valueOf(EntityEvent.STOP_ATTACKING)); // not used on client anywhere
+        events.remove(Byte.valueOf(EntityEvent.USE_ITEM_COMPLETE)); // not suitable for API (complete using item on Player)
+        events.remove(Byte.valueOf(EntityEvent.FISHING_ROD_REEL_IN)); // not suitable for API (fishing rod reel in on FishingHook)
+        events.add((byte) 0); // handled on Arrow (for some reason it's not in the EntityEvent nms file as a constant)
+        return events;
+    }
+
+    private static boolean isNotDeprecated(EntityEffect effect) throws ReflectiveOperationException {
+        return !EntityEffect.class.getDeclaredField(effect.name()).isAnnotationPresent(Deprecated.class);
+    }
+
+    @Test
+    public void checkAllApiExists() throws ReflectiveOperationException {
+        Map<Byte, EntityEffect> toId = new HashMap<>();
+        for (final EntityEffect effect : EntityEffect.values()) {
+            if (isNotDeprecated(effect)) {
+                toId.put(effect.getData(), effect);
+            }
+        }
+
+        final Set<Byte> missingEvents = new HashSet<>();
+        for (final Byte event : collectNmsLevelEvents()) {
+            if (toId.get(event) == null) {
+                missingEvents.add(event);
+            }
+        }
+        if (!missingEvents.isEmpty()) {
+            fail("Missing API EntityEffects:\n" + Joiner.on("\n").join(missingEvents));
+        }
+    }
+
+    @Test
+    public void checkNoExtraApi() throws ReflectiveOperationException {
+        Map<Byte, EntityEffect> toId = new HashMap<>();
+        for (final EntityEffect effect : EntityEffect.values()) {
+            if (isNotDeprecated(effect)) {
+                toId.put(effect.getData(), effect);
+            }
+        }
+
+        final List<Byte> nmsEvents = collectNmsLevelEvents();
+        final Set<EntityEffect> extraApiEffects = new HashSet<>();
+        for (final Map.Entry<Byte, EntityEffect> entry : toId.entrySet()) {
+            if (!nmsEvents.contains(entry.getKey())) {
+                extraApiEffects.add(entry.getValue());
+            }
+        }
+        if (!extraApiEffects.isEmpty()) {
+            fail("Extra API EntityEffects:\n" + Joiner.on("\n").join(extraApiEffects));
+        }
+    }
+}