Improve 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));
+        }
+    }
+}