fix(rcon): validate privileged payloads

Emulator/src/test/java/com/eu/habbo/messages/rcon/RconPayloadValidatorTest.java

@@ -0,0 +1,44 @@
+package com.eu.habbo.messages.rcon;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class RconPayloadValidatorTest {
+    @Test
+    void acceptsValidAnnotatedPayloads() {
+        SetRank.JSONSetRank payload = new SetRank.JSONSetRank();
+        payload.user_id = 1;
+        payload.rank = 2;
+
+        assertNull(RconPayloadValidator.validate(payload));
+    }
+
+    @Test
+    void rejectsInvalidSetRankPayloadsBeforeDispatch() {
+        SetRank.JSONSetRank payload = new SetRank.JSONSetRank();
+        payload.user_id = 0;
+        payload.rank = 2;
+
+        assertEquals("invalid user", RconPayloadValidator.validate(payload));
+    }
+
+    @Test
+    void rejectsInvalidGrantPayloadsBeforeDispatch() {
+        GiveCredits.JSONGiveCredits payload = new GiveCredits.JSONGiveCredits();
+        payload.user_id = 1;
+        payload.credits = 0;
+
+        assertEquals("invalid credits", RconPayloadValidator.validate(payload));
+    }
+
+    @Test
+    void rejectsBlankBadgePayloadsBeforeDispatch() {
+        GiveBadge.GiveBadgeJSON payload = new GiveBadge.GiveBadgeJSON();
+        payload.user_id = 1;
+        payload.badge = " ";
+
+        assertEquals("invalid badge", RconPayloadValidator.validate(payload));
+    }
+}