Further safety checks for correct packets types

common/src/main/java/us/myles/ViaVersion/api/protocol/ClientboundPacketType.java

@@ -4,15 +4,5 @@ package us.myles.ViaVersion.api.protocol;
  * Interface to be implemented by server outgoing packet type enums,
  * representing PLAY state packets, ordered by their packet id.
  */
-public interface ClientboundPacketType {
+public interface ClientboundPacketType extends PacketType {
-
-    /**
-     * @return name of the packet, to be consistent over multiple versions
-     */
-    String name();
-
-    /**
-     * @return ordinal, being the packet id for the implemented protocol
-     */
-    int ordinal();
 }

common/src/main/java/us/myles/ViaVersion/api/protocol/PacketType.java

@@ -0,0 +1,20 @@
+package us.myles.ViaVersion.api.protocol;
+
+/**
+ * Interface representing PLAY state packets, ordered by their packet id.
+ *
+ * @see ClientboundPacketType
+ * @see ServerboundPacketType
+ */
+public interface PacketType {
+
+    /**
+     * @return name of the packet, to be consistent over multiple versions
+     */
+    String name();
+
+    /**
+     * @return ordinal, being the packet id for the implemented protocol
+     */
+    int ordinal();
+}

common/src/main/java/us/myles/ViaVersion/api/protocol/Protocol.java

@@ -284,6 +284,8 @@ public abstract class Protocol<C1 extends ClientboundPacketType, C2 extends Clie
      * @param packetRemapper remapper
      */
     public void registerOutgoing(C1 packetType, @Nullable PacketRemapper packetRemapper) {
+        checkPacketType(packetType, packetType.getClass() == oldClientboundPacketEnum);
+
         ClientboundPacketType mappedPacket = oldClientboundPacketEnum == newClientboundPacketEnum ? packetType
                 : Arrays.stream(newClientboundPacketEnum.getEnumConstants()).filter(en -> en.name().equals(packetType.name())).findAny().orElse(null);
         Preconditions.checkNotNull(mappedPacket, "Packet type " + packetType + " in " + packetType.getClass().getSimpleName() + " could not be automatically mapped!");
@@ -301,6 +303,9 @@ public abstract class Protocol<C1 extends ClientboundPacketType, C2 extends Clie
      * @param packetRemapper   remapper
      */
     public void registerOutgoing(C1 packetType, @Nullable C2 mappedPacketType, @Nullable PacketRemapper packetRemapper) {
+        checkPacketType(packetType, packetType.getClass() == oldClientboundPacketEnum);
+        checkPacketType(mappedPacketType, mappedPacketType == null || mappedPacketType.getClass() == newClientboundPacketEnum);
+
         registerOutgoing(State.PLAY, packetType.ordinal(), mappedPacketType != null ? mappedPacketType.ordinal() : -1, packetRemapper);
     }
 
@@ -326,7 +331,7 @@ public abstract class Protocol<C1 extends ClientboundPacketType, C2 extends Clie
      * @param packetRemapper remapper
      */
     public void registerIncoming(S2 packetType, @Nullable PacketRemapper packetRemapper) {
-        Preconditions.checkArgument(packetType.getClass() == newServerboundPacketEnum);
+        checkPacketType(packetType, packetType.getClass() == newServerboundPacketEnum);
 
         ServerboundPacketType mappedPacket = oldServerboundPacketEnum == newServerboundPacketEnum ? packetType
                 : Arrays.stream(oldServerboundPacketEnum.getEnumConstants()).filter(en -> en.name().equals(packetType.name())).findAny().orElse(null);
@@ -345,6 +350,9 @@ public abstract class Protocol<C1 extends ClientboundPacketType, C2 extends Clie
      * @param packetRemapper   remapper
      */
     public void registerIncoming(S2 packetType, @Nullable S1 mappedPacketType, @Nullable PacketRemapper packetRemapper) {
+        checkPacketType(packetType, packetType.getClass() == newServerboundPacketEnum);
+        checkPacketType(mappedPacketType, mappedPacketType == null || mappedPacketType.getClass() == oldServerboundPacketEnum);
+
         registerIncoming(State.PLAY, mappedPacketType != null ? mappedPacketType.ordinal() : -1, packetType.ordinal(), packetRemapper);
     }
 
@@ -410,6 +418,17 @@ public abstract class Protocol<C1 extends ClientboundPacketType, C2 extends Clie
         }
     }
 
+    /**
+     * @param packetType packet type
+     * @param isValid    expression to check the packet's validity
+     * @throws IllegalArgumentException if the given expression is not met
+     */
+    private void checkPacketType(PacketType packetType, boolean isValid) {
+        if (!isValid) {
+            throw new IllegalArgumentException("Packet type " + packetType + " in " + packetType.getClass().getSimpleName() + " is taken from the wrong enum");
+        }
+    }
+
     public @Nullable <T> T get(Class<T> objectClass) {
         return (T) storedObjects.get(objectClass);
     }

common/src/main/java/us/myles/ViaVersion/api/protocol/ServerboundPacketType.java

@@ -4,15 +4,5 @@ package us.myles.ViaVersion.api.protocol;
  * Interface to be implemented by server incoming packet type enums,
  * representing PLAY state packets, ordered by their packet id.
  */
-public interface ServerboundPacketType {
+public interface ServerboundPacketType extends PacketType {
-
-    /**
-     * @return name of the packet, to be consistent over multiple versions
-     */
-    String name();
-
-    /**
-     * @return ordinal, being the packet id for the implemented protocol
-     */
-    int ordinal();
 }