snowman-repos

"use strict";

// Listen to fetch events
self.addEventListener('fetch', function(event) {

  // Check if the image is a jpeg
  if (/\.jpg$|.png$/.test(event.request.url)) {

  // Inspect the accept header for WebP support
  var supportsWebp = false;

snowman-repos

JavaScript Best Practices

Code conventions

Closing/opening brackets

Although this isn't a problem in other languages, because of semicolon insertion, there could be problems if you don't place the bracket on the opening line:

// no:
function()
{