Fix silent equipment change for mobs

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

@@ -0,0 +1,52 @@
+package io.papermc.paper.entity;
+
+import io.github.classgraph.ClassGraph;
+import io.github.classgraph.ClassInfo;
+import io.github.classgraph.MethodInfo;
+import io.github.classgraph.MethodInfoList;
+import io.github.classgraph.MethodParameterInfo;
+import io.github.classgraph.ScanResult;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Stream;
+import org.bukkit.support.environment.Normal;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import static org.junit.jupiter.api.Assertions.fail;
+
+@Normal
+public class EntitySetItemSlotSilentOverrideTest {
+
+    public static Stream<ClassInfo> parameters() {
+        final List<ClassInfo> classInfo = new ArrayList<>();
+        try (ScanResult scanResult = new ClassGraph()
+            .enableClassInfo()
+            .enableMethodInfo()
+            .whitelistPackages("net.minecraft")
+            .scan()
+        ) {
+            for (final ClassInfo subclass : scanResult.getSubclasses("net.minecraft.world.entity.LivingEntity")) {
+                final MethodInfoList setItemSlot = subclass.getDeclaredMethodInfo("setItemSlot");
+                if (!setItemSlot.isEmpty()) {
+                    classInfo.add(subclass);
+                }
+            }
+        }
+        return classInfo.stream();
+    }
+
+    @ParameterizedTest
+    @MethodSource("parameters")
+    public void checkSetItemSlotSilentOverrides(ClassInfo overridesSetItemSlot) {
+        final MethodInfoList setItemSlot = overridesSetItemSlot.getDeclaredMethodInfo("setItemSlot");
+        for (final MethodInfo methodInfo : setItemSlot) {
+            for (final MethodParameterInfo methodParameterInfo : methodInfo.getParameterInfo()) {
+                if ("boolean".equals(methodParameterInfo.getTypeDescriptor().toStringWithSimpleNames())) {
+                    return;
+                }
+            }
+        }
+        fail(overridesSetItemSlot.getName() + " needs to override setItemSlot with the boolean silent parameter as well");
+    }
+}