Custom Extension Types (Codecs) for TypeScript class

[yohei1126]

I want to write Custom Extension Types (Codecs) for TypeScript class but I got the following error.
Please let me know how I can fix this issue. Thanks!

my target TypeScript code

import * as msgpack from "msgpack-lite";

var codec = msgpack.createCodec();
codec.addExtPacker(0x3F, MyVector, myVectorPacker);
codec.addExtUnpacker(0x3F, myVectorUnpacker);

var data = new MyVector(1, 2);
var encoded = msgpack.encode(data, {codec: codec});
var decoded = msgpack.decode(encoded, {codec: codec});

console.log("encoded = " + JSON.stringify(encoded));
console.log("decoded = " + JSON.stringify(decoded));

class MyVector {
  x: number;
  y: number;
  constructor (x: number, y: number) {
    this.x = x;
    this.y = y;
  }
}

// return Buffer serialized
function myVectorPacker(vector: MyVector) {
  var array = [vector.x, vector.y];
  return msgpack.encode(array);
}

// return Object deserialized
function myVectorUnpacker(buffer: Buffer) {
  var array = msgpack.decode(buffer);
  return new MyVector(array[0], array[1]);
}

compiled JS code

"use strict";
var msgpack = require("msgpack-lite");
var codec = msgpack.createCodec();
codec.addExtPacker(0x3F, MyVector, myVectorPacker);
codec.addExtUnpacker(0x3F, myVectorUnpacker);
var data = new MyVector(1, 2);
var encoded = msgpack.encode(data, { codec: codec });
var decoded = msgpack.decode(encoded, { codec: codec });
console.log("encoded = " + JSON.stringify(encoded));
console.log("decoded = " + JSON.stringify(decoded));
var MyVector = (function () {
    function MyVector(x, y) {
        this.x = x;
        this.y = y;
    }
    return MyVector;
}());
// return Buffer serialized
function myVectorPacker(vector) {
    var array = [vector.x, vector.y];
    return msgpack.encode(array);
}
// return Object deserialized
function myVectorUnpacker(buffer) {
    var array = msgpack.decode(buffer);
    return new MyVector(array[0], array[1]);
}

run time error

D:\work\msgpack-lite-cutome-extention-types>node .
D:\work\msgpack-lite-cutome-extention-types\node_modules\msgpack-lite\lib\write-core.js:40
  var name = Class.name;
                  ^

TypeError: Cannot read property 'name' of undefined
    at Codec.addExtPacker (D:\work\msgpack-lite-cutome-extention-types\node_modules\msgpack-lite\lib\write-core.js:40:19)
    at Object.<anonymous> (D:\work\msgpack-lite-cutome-extention-types\dist\index.js:4:7)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)
    at Module.runMain (module.js:604:10)
    at run (bootstrap_node.js:394:7)
    at startup (bootstrap_node.js:149:9)