Register service worker failed with localhost

Question

I have the following error when I try to register a service worker in a basic app served by a node Express V4 server / on Chrome 42:

DOMException: Failed to register a ServiceWorker: A bad HTTP response code (404) was received when fetching the script. {message: "Failed to register a ServiceWorker: A bad HTTP res…code (404) was received when fetching the script.", name: "NetworkError", code: 19, INDEX_SIZE_ERR: 1, DOMSTRING_SIZE_ERR: 2…} code: 19 message: "Failed to

Here is the register code :

    if ('serviceWorker' in navigator){
    console.log("SW present !!! ");

    navigator.serviceWorker.register('worker.js', {
      //scope: '/toto/'
    }).then(function(registration){
      console.log('Service worker registered : ', registration.scope);
    })
    .catch(function(err){
      console.log("Service worker registration failed : ", err);
    });

  }

Answer 1

I think You are trying to Register non-existent script. In this case this issue comes. Please check your script path and scope path. Maybe you don't have any 'worker.js' in the directory where this script exists. If this is the case, please provide full path or provide worker.js in same directory.

Answer 2

I also had this error when using an express server. It turns out the problem was with the server setup itself, not the service worker registration code. I had told my express app to get index.html as the default root using:

app.get('/', function(req, res) {
    res.sendFile(path.join(__dirname + '/index.html'));
});

However I had not told express the location of any other files I wanted it to be able to use. At this stage my only other file was the service worker file which was sitting at the root of the directory so I fixed the problem by adding this line to the server file:

app.use(express.static(__dirname + '/'));

To debug whether your issue is with the server itself you could download Web Server for Chrome and point it at the root directory of your app. Check the server is started and click on the Web Server URL. If your service worker registration now succeeds you'll know it's a problem with your express server setup not your service worker registration code.