Conventions

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "The skipWaiting() method is used inside the active event handler, which in turn uses Clients.claim()."

A block of code is set as follows:

self.oninstall = function(event) {
  event.waitUntil(
    fetch(zipURL)
      .then(function(res) {
        return res.arrayBuffer();
      })
      .then(getZipFileReader)
      .then(cacheFileContents)
      .then(self.skipWaiting.bind(self))
  );
};

Any command-line input or output is written as follows:

$ git add –all
$ git commit -m "initial commit"
$ git push -u origin master

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes, for example, appear in the text like this: "Finally, in the sidebar on the left-hand side, select Credentials."