transit-js bridge to immutable 3.0

TransitSvc.js

define(['transit', 'immutable'], function (Transit, Imm) {
  'use strict';

  var reader = Transit.reader('json', {
    arrayBuilder: {
      init: function () { return Imm.List.of().asMutable(); },
      add: function (ret, val) { return ret.push(val); },
      finalize: function (ret) { return ret.asImmutable(); },
      fromArray: function (arr) { return Imm.List(arr); }
    },
    mapBuilder: {
      init: function () { return Imm.Map().asMutable(); },
      add: function (ret, key, val) { return ret.set(key, val);  },
      finalize: function (ret) { return ret.asImmutable(); }
    },
    handlers: {
      set: function (arr) {
        return Imm.Set(arr);
      },
      orderedMap: function (arr) {
        return Imm.OrderedMap(arr);
      }
    }
  });

  var writer = Transit.writer("json-verbose", {
    handlers: Transit.map([
      Imm.List, Transit.makeWriteHandler({
        tag: function () { return 'array'; },
        rep: function (v) { return v; },
        stringRep: function () { return null; }
      }),
      Imm.Map, Transit.makeWriteHandler({
        tag: function () { return 'map'; },
        rep: function (v) { return v; },
        stringRep: function () { return null; }
      }),
      Imm.Set, Transit.makeWriteHandler({
        tag: function () { return 'set'; },
        rep: function (v) { return v.toArray(); },
        stringRep: function () { return null; }
      }),
      Imm.OrderedMap, Transit.makeWriteHandler({
        tag: function () { return 'orderedMap'; },
        rep: function (v) { return v.toArray().filter(function (x) { return x; }); },
        stringRep: function () { return null; }
      })
    ])
  });

  return {

    toTransit: function (immutableValue) {
      return writer.write(immutableValue);
    },

    fromTransit: function (ts) {
      return reader.read(ts);
    }

  };

});

Does this work?