workerのpostMessageの検証。Function混じらなければ文字列化の必要なかった。

index.js

var worker = new Worker('worker.js');

worker.addEventListener('message', function(evt) {
  var meta = evt.data,
  key;
  for (key in meta) {
    console.log(key + ':' +  meta[key]);
  }

}, false);
worker.postMessage({
  s : 'test',
  n : 12345,
  b : true,
  d : new Date(),
  a : [1,2,3],
  o : {
    n : 12345
  }
});

try {
  worker.postMessage({
    s : 'test',
    n : 12345,
    b : true,
    f : function() {},
    d : new Date(),
    a : [1,2,3],
    o : {
      n : 12345
    }
  });
} catch(e) {
  console.error(e.name, e.message);
}

worker.js

addEventListener('message', function(evt) {

  var data = evt.data,
  key, type, value,
  toString = Object.prototype.toString,
  meta = {};

  for (key in data) {
    if (data.hasOwnProperty(key)) {
      value = data[key];
      type = typeof(value);
      if (type === 'object') {
        if (Array.isArray(value)) {
          type = 'array';
        } else if(toString.apply(value) === '[object Date]') {
          type = 'date';
        }
      }
      meta[key] = type;
    }
  }

  postMessage(meta);
  
}, false);