WebWorker postMessage for debug

webworker-debug.js

//
// In the Main thread
//
var worker = new Worker('/path/of/webworker/code.js')
worker.onmessage = function (e) {
  var result = JSON.parse(e.data);
  if(result.type == 'debug') {
    console.log(result.msg);
  } else if(result.type == 'response') {
    // ... use result.answer ...
  }
}


//
// In the WebWorker
//
function debug(msg) {                                                           
  postMessage(JSON.stringify({type:'debug',msg:msg}));                          
}

onmessage = function (e) {
  var inputData = e.data;
  // work on input data
  debug('Working OK');
  // work some more
  // ...
  postMessage(JSON.stringify({type:'response', answer:42}));
};