feat: Add basic methods for using PacketSerializer with optional values

src/main/java/net/hypixel/modapi/HypixelModAPI.java

@@ -16,6 +16,7 @@
 import net.hypixel.modapi.serializer.PacketSerializer;
 
 import java.util.List;
+import java.util.Optional;
 import java.util.concurrent.CopyOnWriteArrayList;
 
 public class HypixelModAPI {
@@ -65,9 +66,9 @@ public void handle(String identifier, PacketSerializer serializer) {
         }
 
         // All responses contain a boolean of if the response is a success, if not then a further var int is included to identify the error
-        if (!serializer.readBoolean()) {
-            ErrorReason reason = ErrorReason.getById(serializer.readVarInt());
-            throw new ModAPIException(identifier, reason);
+        Optional<ErrorReason> errorReasonOptional = serializer.readOptional(PacketSerializer::readVarInt).map(ErrorReason::getById);
+        if (errorReasonOptional.isPresent()) {
+            throw new ModAPIException(identifier, errorReasonOptional.get());
         }
 
         ClientboundHypixelPacket packet = registry.createClientboundPacket(identifier, serializer);

src/main/java/net/hypixel/modapi/packet/impl/clientbound/ClientboundLocationPacket.java

@@ -41,10 +41,10 @@ public ClientboundLocationPacket(PacketSerializer serializer) {
         this.environment = Environment.getById(serializer.readVarInt()).orElseThrow(() -> new IllegalArgumentException("Invalid environment ID"));
         this.proxyName = serializer.readString();
         this.serverName = serializer.readString();
-        this.serverType = serializer.readBoolean() ? ServerType.valueOf(serializer.readString()).orElse(null) : null;
-        this.lobbyName = serializer.readBoolean() ? serializer.readString() : null;
-        this.mode = serializer.readBoolean() ? serializer.readString() : null;
-        this.map = serializer.readBoolean() ? serializer.readString() : null;
+        this.serverType = serializer.readOptional(PacketSerializer::readString).flatMap(ServerType::valueOf).orElse(null);
+        this.lobbyName = serializer.readOptionally(PacketSerializer::readString);
+        this.mode = serializer.readOptionally(PacketSerializer::readString);
+        this.map = serializer.readOptionally(PacketSerializer::readString);
     }
 
     @Override
@@ -53,26 +53,10 @@ public void write(PacketSerializer serializer) {
         serializer.writeVarInt(environment.ordinal());
         serializer.writeString(proxyName);
         serializer.writeString(serverName);
-
-        serializer.writeBoolean(serverType != null);
-        if (serverType != null) {
-            serializer.writeString(serverType.name());
-        }
-
-        serializer.writeBoolean(lobbyName != null);
-        if (lobbyName != null) {
-            serializer.writeString(lobbyName);
-        }
-
-        serializer.writeBoolean(mode != null);
-        if (mode != null) {
-            serializer.writeString(mode);
-        }
-
-        serializer.writeBoolean(map != null);
-        if (map != null) {
-            serializer.writeString(map);
-        }
+        serializer.writeOptionally(serverType, (s, t) -> s.writeString(t.name()));
+        serializer.writeOptionally(lobbyName, PacketSerializer::writeString);
+        serializer.writeOptionally(mode, PacketSerializer::writeString);
+        serializer.writeOptionally(map, PacketSerializer::writeString);
     }
 
     @Override

src/main/java/net/hypixel/modapi/packet/impl/clientbound/ClientboundPlayerInfoPacket.java

@@ -33,7 +33,7 @@ public ClientboundPlayerInfoPacket(PacketSerializer serializer) {
         this.playerRank = PlayerRank.getById(serializer.readVarInt()).orElseThrow(() -> new IllegalArgumentException("Invalid player rank ID"));
         this.packageRank = PackageRank.getById(serializer.readVarInt()).orElseThrow(() -> new IllegalArgumentException("Invalid package rank ID"));
         this.monthlyPackageRank = MonthlyPackageRank.getById(serializer.readVarInt()).orElseThrow(() -> new IllegalArgumentException("Invalid monthly package rank ID"));
-        this.prefix = serializer.readBoolean() ? serializer.readString() : null;
+        this.prefix = serializer.readOptionally(PacketSerializer::readString);
     }
 
     @Override
@@ -42,10 +42,7 @@ public void write(PacketSerializer serializer) {
         serializer.writeVarInt(playerRank.getId());
         serializer.writeVarInt(packageRank.getId());
         serializer.writeVarInt(monthlyPackageRank.getId());
-        serializer.writeBoolean(prefix != null);
-        if (prefix != null) {
-            serializer.writeString(prefix);
-        }
+        serializer.writeOptionally(prefix, PacketSerializer::writeString);
     }
 
     @Override

src/main/java/net/hypixel/modapi/serializer/PacketSerializer.java

@@ -4,8 +4,12 @@
 import io.netty.handler.codec.DecoderException;
 import io.netty.handler.codec.EncoderException;
 import io.netty.util.CharsetUtil;
+import org.jetbrains.annotations.Nullable;
 
+import java.util.Optional;
 import java.util.UUID;
+import java.util.function.BiConsumer;
+import java.util.function.Function;
 
 public class PacketSerializer {
     private static final int MAX_BYTES_PER_CHAR_UTF8 = (int) CharsetUtil.getEncoder(CharsetUtil.UTF_8).maxBytesPerChar();
@@ -135,4 +139,25 @@ public PacketSerializer writeUuid(UUID uuid) {
         return this;
     }
 
+    public <T> Optional<T> readOptional(Function<PacketSerializer, T> function) {
+        return this.readBoolean() ? Optional.of(function.apply(this)) : Optional.empty();
+    }
+
+    @Nullable
+    public <T> T readOptionally(Function<PacketSerializer, T> function) {
+        return this.readBoolean() ? function.apply(this) : null;
+    }
+
+    public <T> PacketSerializer writeOptional(Optional<T> optional, BiConsumer<PacketSerializer, T> consumer) {
+        return writeOptionally(optional.orElse(null), consumer);
+    }
+
+    public <T> PacketSerializer writeOptionally(@Nullable T value, BiConsumer<PacketSerializer, T> consumer) {
+        this.writeBoolean(value != null);
+        if (value != null) {
+            consumer.accept(this, value);
+        }
+        return this;
+    }
+
 }