request header not set to text/event-stream for Eventsource calls

I have the following Eventsource.

 var source = new EventSource('/events');
    source.onmessage = function(e) {
      document.body.innerHTML += e.data + '<br>';
    };

The problem is, the Accept request header is automatically set to text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8.

In node.js i'm handling the request with the following condition. 

if (req.headers.accept && req.headers.accept != 'text/event-stream') {..}

Because of this im unable to stream data. Please let me know how to set accept request header to text/event-stream while calling EventSource('/events');

Why don't you just do this:

if(req.url == '/events'){
    res.writeHead(200,{'content-type':'text/event-stream'});
    //Your sse code here...
    sendMsg('some data...');
}

It's more straightforward and you don't need to deal with the request header problem anymore.

you can not do this the browser sets Accept header for you

an EventSource object makes request with "text/event-stream" accept header under Chrome, Firefox and Opera check, that you are handling the right request