Unusual EventSource error in Firefox

Question

Unlike others, for me the EventSource is getting triggered and working fine in both Chrome and Firefox. But in Firefox whenever I receive a message in browser, I receive an error message along with it. Does not happen in Chrome.

Client code:

var source = new EventSource('***');
source.addEventListener('message', function(event) { 
    ...
}, false);
source.addEventListener('ping', function(e) {
    ...
}, false);

source.addEventListener('error', function(e) {
    ... // now this part gets executed in firefox, whenever i recieve a msg
}, false);

Server, nodejs code:

    ***.on('fin',function(message){
        delete ***;
        res.header('Content-Type', 'text/event-stream');
        res.write('data: '+JSON.stringify(message)+'\n\n');
        res.end();
    });
    ***.on('busError',function(){
        delete ***;
        res.send(500);
    });

Answer 1

found the solution myself,

apparantly there is one important header, Transfer-Encoding - it should either be removed, or kept as identity, i guess in firefox, it is taken as chunks by default and that was causing the problem.

once i added the below line in server, error flew away.

res.header('Transfer-Encoding', 'identity');

my source the answer to another problem .

documentation