Before we get into the examples, let's take a look at how the service worker can be used along with the Electron application. In Chrome browser, you can check whether a service worker is enabled for a page by navigating to chrome://inspect/#service-workers. Also, the Chrome developer tools have a tab named Application , which can be used to inspect the service workers, including the cached files and resources.

With Electron, you can open the inspector programmatically by calling the inspectServiceWorker  method of the webContent API:

const { BrowserWindow, app } = require('electron');

let appShell;
function createElectronShell() {
   appShell = new BrowserWindow({ width: 800, height: 600 });
   appShell.loadURL(appUrl);
   appShell.on('closed', () => { appShell = null; });

   // Add this two line of code
   const contents = appShell.webContents;
   contents.inspectServiceWorker();
}

app.on('ready', createElectronShell);

This will open the service worker inspector like the following image:

You can use the hasServiceWorker method to check whether any service worker is registered. The code is as follows:

browserWindow.webContents.hasServiceWorker();

A service worker can be uninstalled programmatically, as follows:

browserWindow.webContents.unregisterServiceWorker();

These methods are built into the Electron shell by default. One thing you need to take care about service worker is that the content should be served through a https protocol, which means the connection to the remote host should be secured using the certificate. Let's check a practical example. The following example checks how we can cache the remote content using the service worker API. We will be also discussing some other interesting service worker features, such as background sync and push notifications. Let's do these things for an Electron application.

The basic requirement for a service worker is that the connection to the remote host should be secured. So, we will create a simple https server using Node.js for testing purposes. Then, our Electron client will connect to this server, and we can play with the service worker features in the Electron.