Add Shearable API

paper-server/src/test/java/io/papermc/paper/entity/ShearableTest.java

@@ -0,0 +1,30 @@
+package io.papermc.paper.entity;
+
+import com.destroystokyo.paper.entity.ai.MobGoalHelper;
+import io.github.classgraph.ClassGraph;
+import io.github.classgraph.ScanResult;
+import java.util.List;
+import net.minecraft.world.entity.Mob;
+import net.minecraft.world.entity.Shearable;
+import org.bukkit.support.environment.Normal;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+@Normal
+class ShearableTest {
+
+    static List<Class<Shearable>> nmsShearables() {
+        try (final ScanResult result = new ClassGraph().enableClassInfo().whitelistPackages("net.minecraft.world.entity").scan()) {
+            return result.getClassesImplementing(Shearable.class.getName()).loadClasses(Shearable.class);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    @ParameterizedTest
+    @MethodSource("nmsShearables")
+    void ensureImplementsShearable(final Class<? extends Shearable> shearableNmsClass) {
+        final Class<? extends org.bukkit.entity.Mob> bukkitClass = MobGoalHelper.toBukkitClass((Class<? extends Mob>) shearableNmsClass);
+        Assertions.assertTrue(io.papermc.paper.entity.Shearable.class.isAssignableFrom(bukkitClass), bukkitClass.getName() + " does not implement Shearable");
+    }
+}