Delay led in Johnny-five

How do I a loop in javascript with API johnny-five/arduino. This looping is to delay on/off to my led. Example:

while(true){
    while(time<1500){
        'led off'
    }
    while(time<1500){
        'led on'
   }

}

My actual code is bellow. I remove the header http and others and the listen in the end.

arduino or board on:

arduino.on('ready', function(){
  console.log("Arduino Pronto");

  led0 = new five.Led(13);
  led1 = new five.Led(12);
  led2 = new five.Led(11);

  this.digitalRead(10, function(value) {
    console.log(value);
  });
});

Server function:

  function servidor(req, res){
  var url = req.url;
  if(url == '/'){
    res.writeHead(200);
    res.end(fs.readFileSync('view/index.html'));
  }else if(url == '/led0'){
    res.writeHead(302, {'Location': '/'});
    res.end();
    led0.toggle();
  }else if(url == '/led1'){
    res.writeHead(302, {'Location': '/'});
    res.end();
    led1.toggle();
  }else if(url == '/led2'){
    res.writeHead(302, {'Location': '/'});
    res.end();
    led2.toggle();
  }else{
    res.writeHead(200);
    res.end("<h1>Erro 404</h1>");
  }

};

Its possible?

You can delay your LEDs using setTimeout for a single delay or setInterval for a repeated delay:

setInterval(() => {
  led.toggle();
}, 1500);

This is an asynchronous delay. If you need a synchronous delay, you could use the sleep package or use execSync from the Node child_process module: execSync("sleep 1.5").