Convert sharable ChannelHandlers to objects where possible

Signed-off-by: Graham <gpe@openrs2.org>

protocol/src/main/kotlin/org/openrs2/protocol/js5/Js5RequestEncoder.kt

@@ -6,7 +6,7 @@ import io.netty.channel.ChannelHandlerContext
 import io.netty.handler.codec.MessageToByteEncoder
 
 @ChannelHandler.Sharable
-public class Js5RequestEncoder : MessageToByteEncoder<Js5Request>(Js5Request::class.java) {
+public object Js5RequestEncoder : MessageToByteEncoder<Js5Request>(Js5Request::class.java) {
     override fun encode(ctx: ChannelHandlerContext, msg: Js5Request, out: ByteBuf) {
         when (msg) {
             is Js5Request.Group -> {

protocol/src/main/kotlin/org/openrs2/protocol/js5/Js5ResponseEncoder.kt

@@ -8,7 +8,7 @@ import io.netty.handler.codec.MessageToByteEncoder
 import kotlin.math.min
 
 @ChannelHandler.Sharable
-public class Js5ResponseEncoder : MessageToByteEncoder<Js5Response>(Js5Response::class.java) {
+public object Js5ResponseEncoder : MessageToByteEncoder<Js5Response>(Js5Response::class.java) {
     override fun encode(ctx: ChannelHandlerContext, msg: Js5Response, out: ByteBuf) {
         out.writeByte(msg.archive)
         out.writeShort(msg.group)

protocol/src/test/kotlin/org/openrs2/protocol/js5/Js5RequestEncoderTest.kt

@@ -20,7 +20,7 @@ object Js5RequestEncoderTest {
     }
 
     private fun testEncode(request: Js5Request, expected: ByteArray) {
-        val channel = EmbeddedChannel(Js5RequestEncoder())
+        val channel = EmbeddedChannel(Js5RequestEncoder)
         channel.writeOutbound(request)
 
         channel.readOutbound<ByteBuf>().use { actual ->

protocol/src/test/kotlin/org/openrs2/protocol/js5/Js5ResponseEncoderTest.kt

@@ -33,7 +33,7 @@ object Js5ResponseEncoderTest {
 
     @Test
     fun testEncodeEmpty() {
-        val channel = EmbeddedChannel(Js5ResponseEncoder())
+        val channel = EmbeddedChannel(Js5ResponseEncoder)
 
         assertThrows<EncoderException> {
             channel.writeOutbound(Js5Response(true, 2, 3, Unpooled.EMPTY_BUFFER))
@@ -41,7 +41,7 @@ object Js5ResponseEncoderTest {
     }
 
     private fun testEncode(container: String, encoded: String, prefetch: Boolean) {
-        val channel = EmbeddedChannel(Js5ResponseEncoder())
+        val channel = EmbeddedChannel(Js5ResponseEncoder)
 
         read(container).use { buf ->
             channel.writeOutbound(Js5Response(prefetch, 2, 3, buf.retain()))