Make PacketWrapper exceptions more informative :)

src/main/java/us/myles/ViaVersion/api/PacketWrapper.java

@@ -9,6 +9,7 @@ import us.myles.ViaVersion.api.data.UserConnection;
 import us.myles.ViaVersion.api.remapper.ValueCreator;
 import us.myles.ViaVersion.api.type.Type;
 import us.myles.ViaVersion.api.type.TypeConverter;
+import us.myles.ViaVersion.exception.InformativeException;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -84,7 +85,11 @@ public class PacketWrapper {
         if (readableObjects.isEmpty()) {
             Preconditions.checkNotNull(inputBuffer, "This packet does not have an input buffer.");
             // We could in the future log input read values, but honestly for things like bulk maps, mem waste D:
+            try {
                 return type.read(inputBuffer);
+            } catch (Exception e) {
+                throw new InformativeException(e).set("Type", type.getTypeName()).set("Packet ID", getId());
+            }
         } else {
             Pair<Type, Object> read = readableObjects.poll();
             if (read.getKey().equals(type)) {
@@ -152,8 +157,7 @@ public class PacketWrapper {
                 }
                 packetValue.getKey().write(buffer, value);
             } catch (Exception e) {
-                System.out.println(getId() + " Index: " + index + " Type: " + packetValue.getKey().getTypeName());
+                throw new InformativeException(e).set("Index", index).set("Type", packetValue.getKey().getTypeName()).set("Packet ID", getId());
-                throw e;
             }
             index++;
         }

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

@@ -2,7 +2,7 @@ package us.myles.ViaVersion.api.protocol;
 
 import lombok.AllArgsConstructor;
 import lombok.Getter;
-import us.myles.ViaVersion.CancelException;
+import us.myles.ViaVersion.exception.CancelException;
 import us.myles.ViaVersion.api.PacketWrapper;
 import us.myles.ViaVersion.api.Pair;
 import us.myles.ViaVersion.api.data.UserConnection;

src/main/java/us/myles/ViaVersion/api/remapper/PacketHandler.java

@@ -1,6 +1,7 @@
 package us.myles.ViaVersion.api.remapper;
 
 import us.myles.ViaVersion.api.PacketWrapper;
+import us.myles.ViaVersion.exception.InformativeException;
 
 public abstract class PacketHandler implements ValueWriter {
     /**
@@ -13,6 +14,11 @@ public abstract class PacketHandler implements ValueWriter {
 
     @Override
     public void write(PacketWrapper writer, Object inputValue) throws Exception {
+        try {
             handle(writer);
+        } catch (InformativeException e) {
+            e.addSource(this.getClass());
+            throw e;
+        }
     }
 }

src/main/java/us/myles/ViaVersion/api/remapper/PacketRemapper.java

@@ -3,6 +3,7 @@ package us.myles.ViaVersion.api.remapper;
 import us.myles.ViaVersion.api.PacketWrapper;
 import us.myles.ViaVersion.api.Pair;
 import us.myles.ViaVersion.api.type.Type;
+import us.myles.ViaVersion.exception.InformativeException;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -84,6 +85,7 @@ public abstract class PacketRemapper {
      * @throws Exception Throws if it fails to write / read to the packet.
      */
     public void remap(PacketWrapper packetWrapper) throws Exception {
+        try {
             // Read all the current values
             for (Pair<ValueReader, ValueWriter> valueRemapper : valueRemappers) {
                 Object object = valueRemapper.getKey().read(packetWrapper);
@@ -91,5 +93,9 @@ public abstract class PacketRemapper {
                 valueRemapper.getValue().write(packetWrapper, object);
             }
             // If we had handlers we'd put them here
+        } catch (InformativeException e) {
+            e.addSource(this.getClass());
+            throw e;
+        }
     }
 }

src/main/java/us/myles/ViaVersion/api/remapper/ValueCreator.java

@@ -1,6 +1,7 @@
 package us.myles.ViaVersion.api.remapper;
 
 import us.myles.ViaVersion.api.PacketWrapper;
+import us.myles.ViaVersion.exception.InformativeException;
 
 public abstract class ValueCreator implements ValueWriter {
     /**
@@ -13,6 +14,11 @@ public abstract class ValueCreator implements ValueWriter {
 
     @Override
     public void write(PacketWrapper writer, Object inputValue) throws Exception {
+        try {
             write(writer);
+        } catch (InformativeException e) {
+            e.addSource(this.getClass());
+            throw e;
+        }
     }
 }

src/main/java/us/myles/ViaVersion/api/remapper/ValueTransformer.java

@@ -2,6 +2,7 @@ package us.myles.ViaVersion.api.remapper;
 
 import us.myles.ViaVersion.api.PacketWrapper;
 import us.myles.ViaVersion.api.type.Type;
+import us.myles.ViaVersion.exception.InformativeException;
 
 public abstract class ValueTransformer<T1, T2> implements ValueWriter<T1> {
     private final Type<T2> outputType;
@@ -22,6 +23,11 @@ public abstract class ValueTransformer<T1, T2> implements ValueWriter<T1> {
 
     @Override
     public void write(PacketWrapper writer, T1 inputValue) throws Exception {
+        try {
             writer.write(outputType, transform(writer, inputValue));
+        } catch (InformativeException e) {
+            e.addSource(this.getClass());
+            throw e;
+        }
     }
 }

src/main/java/us/myles/ViaVersion/exception/CancelException.java

@@ -1,4 +1,4 @@
-package us.myles.ViaVersion;
+package us.myles.ViaVersion.exception;
 
 public class CancelException extends Exception {
 }

src/main/java/us/myles/ViaVersion/exception/InformativeException.java

@@ -0,0 +1,50 @@
+package us.myles.ViaVersion.exception;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class InformativeException extends Exception {
+    Map<String, Object> info = new HashMap<>();
+    int sources = 0;
+
+    public InformativeException(Throwable cause) {
+        super(cause);
+    }
+
+    public InformativeException set(String key, Object value) {
+        info.put(key, value);
+        return this;
+    }
+
+    public InformativeException addSource(Class<?> sourceClazz) {
+        return set("Source #" + sources++, getSource(sourceClazz));
+    }
+
+    private String getSource(Class<?> sourceClazz) {
+        if(sourceClazz.isAnonymousClass()){
+            return sourceClazz.getName() + " (Anonymous)";
+        }else{
+            return sourceClazz.getName();
+        }
+    }
+
+    @Override
+    public String getMessage() {
+        StringBuilder builder = new StringBuilder();
+        builder.append("Please post this error to http://github.com/MylesIsCool/ViaVersion/issues\n{");
+        int i = 0;
+        for (Map.Entry<String, Object> entry : info.entrySet()) {
+            builder.append((i == 0 ? "" : ", ") + entry.getKey() + ": " + entry.getValue().toString());
+            i++;
+        }
+        builder.append("}\nActual Error: ");
+
+        return builder.toString();
+    }
+
+    @Override
+    public synchronized Throwable fillInStackTrace() {
+        // Don't record this stack
+        return this;
+    }
+}

src/main/java/us/myles/ViaVersion/handlers/ViaDecodeHandler.java

@@ -3,10 +3,11 @@ package us.myles.ViaVersion.handlers;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.ByteToMessageDecoder;
-import us.myles.ViaVersion.CancelException;
 import us.myles.ViaVersion.api.PacketWrapper;
 import us.myles.ViaVersion.api.data.UserConnection;
 import us.myles.ViaVersion.api.type.Type;
+import us.myles.ViaVersion.exception.CancelException;
+import us.myles.ViaVersion.exception.InformativeException;
 import us.myles.ViaVersion.packets.Direction;
 import us.myles.ViaVersion.protocols.base.ProtocolInfo;
 import us.myles.ViaVersion.util.PipelineUtil;

src/main/java/us/myles/ViaVersion/handlers/ViaEncodeHandler.java

@@ -3,10 +3,11 @@ package us.myles.ViaVersion.handlers;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToByteEncoder;
-import us.myles.ViaVersion.CancelException;
 import us.myles.ViaVersion.api.PacketWrapper;
 import us.myles.ViaVersion.api.data.UserConnection;
 import us.myles.ViaVersion.api.type.Type;
+import us.myles.ViaVersion.exception.CancelException;
+import us.myles.ViaVersion.exception.InformativeException;
 import us.myles.ViaVersion.packets.Direction;
 import us.myles.ViaVersion.protocols.base.ProtocolInfo;
 import us.myles.ViaVersion.util.PipelineUtil;

src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/packets/SpawnPackets.java

@@ -103,7 +103,7 @@ public class SpawnPackets {
                 map(Type.INT, toNewDouble); // 2 - Y - Needs to be divide by 32
                 map(Type.INT, toNewDouble); // 3 - Z - Needs to be divide by 32
 
-                map(Type.SHORT); // 4 - Amount to spawn
+                map(Type.INT); // 4 - Amount to spawn DONT PUSH
             }
         });