A vulnerability has been discovered which allows Node.js integration to be re-enabled in some Electron applications that disable it. This vulnerability has been assigned the CVE identifier CVE-2018-1000136.

Affected Applications​

An application is affected if all of the following are true:

1. Runs on Electron 1.7, 1.8, or a 2.0.0-beta
2. Allows execution of arbitrary remote code
3. Disables Node.js integration
4. Does not explicitly declare webviewTag: false in its webPreferences
5. Does not enable the nativeWindowOption option
6. Does not intercept new-window events and manually override event.newGuest without using the supplied options tag

Although this appears to be a minority of Electron applicatons, we encourage all applications to be upgraded as a precaution.

Mitigation​

This vulnerability is fixed in today's 1.7.13, 1.8.4, and 2.0.0-beta.5 releases.

Developers who are unable to upgrade their application's Electron version can mitigate the vulnerability with the following code:

app.on('web-contents-created', (event, win) => {
  win.on(
    'new-window',
    (event, newURL, frameName, disposition, options, additionalFeatures) => {
      if (!options.webPreferences) options.webPreferences = {};
      options.webPreferences.nodeIntegration = false;
      options.webPreferences.nodeIntegrationInWorker = false;
      options.webPreferences.webviewTag = false;
      delete options.webPreferences.preload;
    },
  );
});

// and *IF* you don't use WebViews at all,
// you might also want
app.on('web-contents-created', (event, win) => {
  win.on('will-attach-webview', (event, webPreferences, params) => {
    event.preventDefault();
  });
});

Further Information​

This vulnerability was found and reported responsibly to the Electron project by Brendan Scarvell of Trustwave SpiderLabs.

To learn more about best practices for keeping your Electron apps secure, see our security tutorial.

To report a vulnerability in Electron, please email security@electronjs.org.

Please join our email list to receive updates about releases and security updates.

Last week the electronjs.org site had a few minutes of downtime. If you were affected by these brief outages, we're sorry for the inconvenience. After a bit of investigation today, we've diagnosed the root cause and have deployed a fix.

To prevent this kind of downtime in the future, we've enabled Heroku threshold alerts on our app. Any time our web server accumulates failed requests or slow responses beyond a certain threshold, our team will be notified so we can address the problem quickly.

Offline Docs in Every Language​

The next time you're developing an Electron app on a plane or in a subterranean coffee shop, you might want to have a copy of the docs for offline reference. Fortunately, Electron's docs are available as Markdown files in over 20 languages.

git clone https://github.com/electron/electron-i18n
ls electron-i18n/content

Offline Docs with a GUI​

devdocs.io/electron is a handy website that stores docs for offline use, not just for Electron but many other projects like JavaScript, TypeScript, Node.js, React, Angular, and many others. And of course there's an Electron app for that, too. Check out devdocs-app on the Electron site.

If you like to install apps without using your mouse or trackpad, give Electron Forge's install command a try:

npx electron-forge install egoist/devdocs-app

A remote code execution vulnerability has been discovered affecting Electron apps that use custom protocol handlers. This vulnerability has been assigned the CVE identifier CVE-2018-1000006.

Affected Platforms​

Electron apps designed to run on Windows that register themselves as the default handler for a protocol, like myapp://, are vulnerable.

Such apps can be affected regardless of how the protocol is registered, e.g. using native code, the Windows registry, or Electron's app.setAsDefaultProtocolClient API.

macOS and Linux are not vulnerable to this issue.

Mitigation​

We've published new versions of Electron which include fixes for this vulnerability: 1.8.2-beta.5, 1.7.12, and 1.6.17. We urge all Electron developers to update their apps to the latest stable version immediately.

If for some reason you are unable to upgrade your Electron version, you can append -- as the last argument when calling app.setAsDefaultProtocolClient, which prevents Chromium from parsing further options. The double dash -- signifies the end of command options, after which only positional parameters are accepted.

app.setAsDefaultProtocolClient(protocol, process.execPath, [
  '--your-switches-here',
  '--',
]);

See the app.setAsDefaultProtocolClient API for more details.

To learn more about best practices for keeping your Electron apps secure, see our security tutorial.

If you wish to report a vulnerability in Electron, email security@electronjs.org.

A new major version of Electron is in the works, and with it some changes to our versioning strategy. As of version 2.0.0, Electron will strictly adhere to Semantic Versioning.

This change means you'll see the major version bump more often, and it will usually be a major update to Chromium. Patch releases will also be more stable, as they will now only contain bug fixes with no new features.

Major Version Increments

• Chromium version updates
• Node.js major version updates
• Electron breaking API changes

Minor Version Increments

• Node.js minor version updates
• Electron non-breaking API changes

Patch Version Increments

• Node.js patch version updates
• fix-related chromium patches
• Electron bug fixes

Because Electron's semver ranges will now be more meaningful, we recommend installing Electron using npm's default --save-dev flag, which will prefix your version with ^, keeping you safely up to date with minor and patch updates:

npm install --save-dev electron

For developers interested only in bug fixes, you should use the tilde semver prefix e.g. ~2.0.0, which which will never introduce new features, only fixes to improve stability.

For more details, see electronjs.org/docs/tutorial/electron-versioning.

Electron has a new website at electronjs.org! We've replaced our static Jekyll site with a Node.js webserver, giving us flexibility to internationalize the site and paving the way for more exciting new features.

🌍 Translations​

We've begun the process of internationalizing the website with the goal of making Electron app development accessible to a global audience of developers. We're using a localization platform called Crowdin that integrates with GitHub, opening and updating pull requests automatically as content is translated into different languages.

Though we've been working quietly on this effort so far, over 75 Electron community members have already discovered the project organically and joined in the effort to internationalize the website and translate Electron's docs into over 20 languages. We are seeing daily contributions from people all over the world, with translations for languages like French, Vietnamese, Indonesian, and Chinese leading the way.

To choose your language and view translation progress, visit electronjs.org/languages

If you're multilingual and interested in helping translate Electron's docs and website, visit the electron/electron-i18n repo, or jump right into translating on Crowdin, where you can sign in using your GitHub account.

There are currently 21 languages enabled for the Electron project on Crowdin. Adding support for more languages is easy, so if you're interested in helping translate but you don't see your language listed, let us know and we'll enable it.

Raw Translated Docs​

If you prefer to read documentation in raw markdown files, you can now do that in any language:

git clone https://github.com/electron/electron-i18n
ls electron-i18n/content

App Pages​

As of today, any Electron app can easily have its own page on the Electron site. For a few examples, check out Etcher, 1Clipboard, or GraphQL Playground, pictured here on the Japanese version of the site:

There are some incredible Electron apps out there, but they're not always easy to find, and not every developer has the time or resources to build a proper website to market and distribute their app.

Using just a PNG icon file and a small amount of app metadata, we're able to collect a lot of information about a given app. Using data collected from GitHub, app pages can now display screenshots, download links, versions, release notes, and READMEs for every app that has a public repository. Using a color palette extracted from each app's icon, we can produce bold and accessible colors to give each app page some visual distinction.

The apps index page now also has categories and a keyword filter to find interesting apps like GraphQL GUIs and p2p tools.

If you've got an Electron app that you'd like featured on the site, open a pull request on the electron/electron-apps repository.

One-line Installation with Homebrew​

The Homebrew package manager for macOS has a subcommand called cask that makes it easy to install desktop apps using a single command in your terminal, like brew cask install atom.

We've begun collecting Homebrew cask names for popular Electron apps and are now displaying the installation command (for macOS visitors) on every app page that has a cask:

To view all the apps that have homebrew cask names, visit electronjs.org/apps?q=homebrew. If you know of other apps with casks that we haven't indexed yet, please add them!

🌐 A New Domain​

We've moved the site from electron.atom.io to a new domain: electronjs.org.

The Electron project was born inside Atom, GitHub's open-source text editor built on web technologies. Electron was originally called atom-shell. Atom was the first app to use it, but it didn't take long for folks to realize that this magical Chromium + Node runtime could be used for all kinds of different applications. When companies like Microsoft and Slack started to make use of atom-shell, it became clear that the project needed a new name.

And so "Electron" was born. In early 2016, GitHub assembled a new team to focus specifically on Electron development and maintenance, apart from Atom. In the time since, Electron has been adopted by thousands of app developers, and is now depended on by many large companies, many of which have Electron teams of their own.

Supporting GitHub's Electron projects like Atom and GitHub Desktop is still a priority for our team, but by moving to a new domain we hope to help clarify the technical distinction between Atom and Electron.

🐢🚀 Node.js Everywhere​

The previous Electron website was built with Jekyll, the popular Ruby-based static site generator. Jekyll is a great tool for building static websites, but the website had started to outgrow it. We wanted more dynamic capabilities like proper redirects and dynamic content rendering, so a Node.js server was the obvious choice.

The Electron ecosystem includes projects with components written in many different programming languages, from Python to C++ to Bash. But JavaScript is foundational to Electron, and it's the language used most in our community.

By migrating the website from Ruby to Node.js, we aim to lower the barrier to entry for people wishing to contribute to the website.

⚡️ Easier Open-Source Participation​

If you've got Node.js (8 or higher) and git installed on your system, you can easily get the site running locally:

git clone https://github.com/electron/electronjs.org
cd electronjs.org
npm install
npm run dev

The new website is hosted on Heroku. We use deployment pipelines and the Review Apps feature, which automatically creates a running copy of the app for every pull request. This makes it easy for reviewers to view the actual effects of a pull request on a live copy of the site.

🙏 Thanks to Contributors​

We'd like to give special thanks to all the folks around the world who have contributed their own time and energy to help improve Electron. The passion of the open-source community has helped immeasurably in making Electron a success. Thank you!

A remote code execution vulnerability has been discovered in Google Chromium that affects all recent versions of Electron. Any Electron app that accesses remote content is vulnerable to this exploit, regardless of whether the sandbox option is enabled.

We've published two new versions of electron 1.7.8 and 1.6.14, both of which include a fix for this vulnerability. We urge all Electron developers to update their apps to the latest stable version immediately:

npm i electron@latest --save-dev

To learn more about best practices for keeping your Electron apps secure, see our security tutorial.

Please contact security@electronjs.org if you wish to report a vulnerability in Electron.

The electron npm package now includes a TypeScript definition file that provides detailed annotations of the entire Electron API. These annotations can improve your Electron development experience even if you're writing vanilla JavaScript. Just npm install electron to get up-to-date Electron typings in your project.

TypeScript is an open-source programming language created by Microsoft. It's a superset of JavaScript that extends the language by adding support for static types. The TypeScript community has grown quickly in recent years, and TypeScript was ranked among the most loved programming languages in a recent Stack Overflow developer survey. TypeScript is described as "JavaScript that scales", and teams at GitHub, Slack, and Microsoft are all using it to write scalable Electron apps that are used by millions of people.

TypeScript supports many of the newer language features in JavaScript like classes, object destructuring, and async/await, but its real differentiating feature is type annotations. Declaring the input and output datatypes expected by your program can reduce bugs by helping you find errors at compile time, and the annotations can also serve as a formal declaration of how your program works.

When libraries are written in vanilla Javascript, the types are often vaguely defined as an afterthought when writing documentation. Functions can often accept more types than what was documented, or a function can have invisible constraints that are not documented, which can lead to runtime errors.

TypeScript solves this problem with definition files. A TypeScript definition file describes all the functions of a library and its expected input and output types. When library authors bundle a TypeScript definition file with their published library, consumers of that library can explore its API right inside their editor and start using it right away, often without needing to consult the library's documentation.

Many popular projects like Angular, Vue.js, node-github (and now Electron!) compile their own definition file and bundle it with their published npm package. For projects that don't bundle their own definition file, there is DefinitelyTyped, a third-party ecosystem of community-maintained definition files.

Installation​

Starting at version 1.6.10, every release of Electron includes its own TypeScript definition file. When you install the electron package from npm, the electron.d.ts file is bundled automatically with the installed package.

The safest way to install Electron is using an exact version number:

npm install electron --save-dev --save-exact

Or if you're using yarn:

yarn add electron --dev --exact

If you were already using third-party definitions like @types/electron and @types/node, you should remove them from your Electron project to prevent any collisions.

The definition file is derived from our structured API documentation, so it will always be consistent with Electron's API documentation. Just install electron and you'll always get TypeScript definitions that are up to date with the version of Electron you're using.

Usage​

For a summary of how to install and use Electron's new TypeScript annotations, watch this short demo screencast:

If you're using Visual Studio Code, you've already got TypeScript support built in. There are also community-maintained plugins for Atom, Sublime, vim, and other editors.

Once your editor is configured for TypeScript, you'll start to see more context-aware behavior like autocomplete suggestions, inline method reference, argument checking, and more.

Getting started with TypeScript​

If you're new to TypeScript and want to learn more, this introductory video from Microsoft provides a nice overview of why the language was created, how it works, how to use it, and where it's headed.

There's also a handbook and a playground on the official TypeScript website.

Because TypeScript is a superset of JavaScript, your existing JavaScript code is already valid TypeScript. This means you can gradually transition an existing JavaScript project to TypeScript, sprinkling in new language features as needed.

Thanks​

This project would not have been possible without the help of Electron's community of open-source maintainers. Thanks to Samuel Attard, Felix Rieseberg, Birunthan Mohanathas, Milan Burda, Brendan Forster, and many others for their bug fixes, documentation improvements, and technical guidance.

Support​

If you encounter any issues using Electron's new TypeScript definition files, please file an issue on the electron-typescript-definitions repository.

Happy TypeScripting!

This week we interviewed the creator of Jasper, an Electron-based tool for managing GitHub notifications.

Hello! Who are you?​

I'm Ryo Maruyama, a software developer in Japan. I am developing Jasper and ESDoc.

What is Jasper?​

Jasper is a flexible and powerful issue reader for GitHub. It supports issues and pull requests on github.com and GitHub Enterprise.

Why did you make it?​

When people use GitHub in their job or OSS activities, they tend to receive many notifications on a daily basis. As a way to subscribe to the notifications, GitHub provides email and web notifications. I used these for a couple of years, but I faced the following problems:

• It's easy to overlook issues where I was mentioned, I commented, or I am watching.
• I put some issues in a corner of my head to check later, but I sometimes forget about them.
• To not forget issues, I keep many tabs open in my browser.
• It's hard to check all issues that are related to me.
• It's hard to grasp all of my team's activity.

I was spending a lot of time and energy trying to prevent those problems, so I decided to make an issue reader for GitHub to solve these problems efficiently, and started developing Jasper.

Who's using Jasper?​

Jasper is used by developers, designers, and managers in several companies that are using GitHub. Of course, some OSS developers also are using it. And it is also used by some people at GitHub!

How does Jasper work?​

Once Jasper is configured, the following screen appears. From left to right, you can see "streams list", "issues list" and "issue body".

This "stream" is the core feature of Jasper. For example, if you want to see "issues that are assigned to @zeke in the electron/electron repository", you create the following stream:

repo:electron/electron assignee:zeke is:issue

After creating the stream and waiting for a few seconds, you can see the issues that meet the conditions.

What can we do with streams?​

I will introduce what kind of conditions can be used for stream.

Users and Teams​

involves means mention, author, assignee or commenter

Repositories and Organizations​

org is same as user

Attributes​

Review Status​

As you may have noticed by looking at these, streams can use GitHub's search queries. For details on how to use streams and search queries, see the following URLs.

• jasperapp.io/doc.html#stream
• help.github.com/articles/searching-issues
• help.github.com/articles/search-syntax

Jasper also has features for unread issue management, unread comment management, marking stars, notification updating, filtering issues, keyboard shortcuts, etc.

Is Jasper a paid product? How much does it cost?​

Jasper is $12. However you can use the free trial edition for 30 days.

Why did you choose to build Jasper on Electron?​

I like the following aspects of Electron:

• Apps can be developed with JavaScript/CSS/HTML.
• Apps can be built for Windows, Mac, and Linux platforms.
• Electron is actively developed and has a large community.

These features enable rapid and simple desktop application development. It is awesome! If you have any product idea, you should consider using Electron by all means.

What are some challenges you've faced while developing Jasper?​

I had a hard time figuring out the "stream" concept. At first I considered using GitHub's Notifications API. However I noticed that it does not support certain use cases. After that I considered using the Issues API and Pull Requests API, in addition to the Notification API. But it never became what I wanted. Then while thinking about various methods, I realized that polling GitHub's Search API would offer the most flexibility. It took about a month of experimentation to get to this point, then I implemented a prototype of Jasper with the stream concept in two days.

Note: The polling is limited to once every 10 seconds at most. This is acceptable enough for the restriction of GitHub API.

What's coming next?​

I have a plan to develop the following features:

• A filtered stream: A stream has some filtered stream that filter issues in the stream. It is like as view of SQL.
• Multiple accounts: you will be able to use both github.com and GHE
• Improve performance: For now the loading a issue in WebView is low speed than normal browser.

Follow @jasperappio on Twitter for updates.

This week we caught up with @feross and @dcposch to talk about WebTorrent, the web-powered torrent client that connects users together to form a distributed, decentralized browser-to-browser network.

What is WebTorrent?​

WebTorrent is the first torrent client that works in the browser. It's written completely in JavaScript and it can use WebRTC for peer-to-peer transport. No browser plugin, extension, or installation is required.

Using open web standards, WebTorrent connects website users together to form a distributed, decentralized browser-to-browser network for efficient file transfer.

You can see a demo of WebTorrent in action here: webtorrent.io.

Why is this cool?​

Imagine a video site like YouTube, but where visitors help to host the site's content. The more people that use a WebTorrent-powered website, the faster and more resilient it becomes.

Browser-to-browser communication cuts out the middle-man and lets people communicate on their own terms. No more client/server – just a network of peers, all equal. WebTorrent is the first step in the journey to re-decentralize the Web.

Where does Electron come into the picture?​

About one year ago, we decided to build WebTorrent Desktop, a version of WebTorrent that runs as a desktop app.

We created WebTorrent Desktop for three reasons:

1. We wanted a clean, lightweight, ad-free, open source torrent app
2. We wanted a torrent app with good streaming support
3. We need a "hybrid client" that connects the BitTorrent and WebTorrent networks

If we can already download torrents in my web browser, why a desktop app?​

First, a bit of background on the design of WebTorrent.

In the early days, BitTorrent used TCP as its transport protocol. Later, uTP came along promising better performance and additional advantages over TCP. Every mainstream torrent client eventually adopted uTP, and today you can use BitTorrent over either protocol. The WebRTC protocol is the next logical step. It brings the promise of interoperability with web browsers – one giant P2P network made up of all desktop BitTorrent clients and millions of web browsers.

“Web peers” (torrent peers that run in a web browser) make the BitTorrent network stronger by adding millions of new peers, and spreading BitTorrent to dozens of new use cases. WebTorrent follows the BitTorrent spec as closely as possible, to make it easy for existing BitTorrent clients to add support for WebTorrent.

Some torrent apps like Vuze already support web peers, but we didn't want to wait around for the rest to add support. So basically, WebTorrent Desktop was our way to speed up the adoption of the WebTorrent protocol. By making an awesome torrent app that people really want to use, we increase the number of peers in the network that can share torrents with web peers (i.e. users on websites).

What are some interesting use cases for torrents beyond what people already know they can do?​

One of the most exciting uses for WebTorrent is peer-assisted delivery. Non-profit projects like Wikipedia and the Internet Archive could reduce bandwidth and hosting costs by letting visitors chip in. Popular content can be served browser-to-browser, quickly and cheaply. Rarely-accessed content can be served reliably over HTTP from the origin server.

The Internet Archive actually already updated their torrent files so they work great with WebTorrent. So if you want to embed Internet Archive content on your site, you can do it in a way that reduces hosting costs for the Archive, allowing them to devote more money to actually archiving the web!

There are also exciting business use cases, from CDNs to app delivery over P2P.

What are some of your favorite projects that use WebTorrent?​

The coolest thing built with WebTorrent, hands down, is probably Gaia 3D Star Map. It's a slick 3D interactive simulation of the Milky Way. The data loads from a torrent, right in your browser. It's awe-inspiring to fly through our star system and realize just how little we humans are compared to the vastness of our universe.

You can read about how this was made in Torrenting The Galaxy, a blog post where the author, Charlie Hoey, explains how he built the star map with WebGL and WebTorrent.

We're also huge fans of Brave. Brave is a browser that automatically blocks ads and trackers to make the web faster and safer. Brave recently added torrent support, so you can view traditional torrents without using a separate app. That feature is powered by WebTorrent.

So, just like how most browsers can render PDF files, Brave can render magnet links and torrent files. They're just another type of content that the browser natively supports.

One of the co-founders of Brave is actually Brendan Eich, the creator of JavaScript, the language we wrote WebTorrent in, so we think it's pretty cool that Brave chose to integrate WebTorrent.

Why did you choose to build WebTorrent Desktop on Electron?​

There is a meme that Electron apps are "bloated" because they include the entire Chrome content module in every app. In some cases, this is partially true (an Electron app installer is usually ~40MB, where an OS-specific app installer is usually ~20MB).

However, in the case of WebTorrent Desktop, we use nearly every Electron feature, and many dozens of Chrome features in the course of normal operation. If we wanted to implement these features from scratch for each platform, it would have taken months or years longer to build our app, or we would have only been able to release for a single platform.

Just to get an idea, we use Electron's dock integration (to show download progress), menu bar integration (to run in the background), protocol handler registration (to open magnet links), power save blocker (to prevent sleep during video playback), and automatic updater. As for Chrome features, we use plenty: the <video> tag (to play many different video formats), the <track> tag (for closed captions support), drag-and-drop support, and WebRTC (which is non-trivial to use in a native app).

Not to mention: our torrent engine is written in JavaScript and assumes the existence of lots of Node APIs, but especially require('net') and require('dgram') for TCP and UDP socket support.

Basically, Electron is just what we needed and had the exact set of features we needed to ship a solid, polished app in record time.

What are your favorite things about Electron?​

The WebTorrent library has been in development as an open source side project for two years. We made WebTorrent Desktop in four weeks. Electron is the primary reason that we were able to build and ship our app so quickly.

Just as Node.js made server programming accessible to a generation of jQuery-using front-end programmers, Electron makes native app development accessible to anyone familiar with Web or Node.js development. Electron is extremely empowering.

Do the website and the Desktop client share code?​

Yes, the webtorrent npm package works in Node.js, in the browser, and in Electron. The exact same code can run in all environments – this is the beauty of JavaScript. It's today's universal runtime. Java Applets promised "Write Once, Run Anywhere" apps, but that vision never really materialized for a number of reasons. Electron, more than any other platform, actually gets pretty darn close to that ideal.

What are some challenges you've faced while building WebTorrent?​

In early versions of the app, we struggled to make the UI performant. We put the torrent engine in the same renderer process that draws the main app window which, predictably, led to slowness anytime there was intense CPU activity from the torrent engine (like verifying the torrent pieces received from peers).

We fixed this by moving the torrent engine to a second, invisible renderer process that we communicate with over IPC. This way, if that process briefly uses a lot of CPU, the UI thread will be unaffected. Buttery-smooth scrolling and animations are so satisfying.

Note: we had to put the torrent engine in a renderer process, instead of a "main" process, because we need access to WebRTC (which is only available in the renderer.)

In what areas should Electron be improved?​

One thing we'd love to see is better documentation about how to build and ship production-ready apps, especially around tricky subjects like code signing and auto-updating. We had to learn about best practices by digging into source code and asking around on Twitter!

Is WebTorrent Desktop done? If not, what's coming next?​

We think the current version of WebTorrent Desktop is excellent, but there's always room for improvement. We're currently working on improving polish, performance, subtitle support, and video codec support.

If you're interested in getting involved in the project, check out our GitHub page!

Any Electron development tips that might be useful to other developers?​

Feross, one of the WebTorrent Desktop contributors, recently gave a talk "Real world Electron: Building Cross-platform desktop apps with JavaScript" at NodeConf Argentina that contains useful tips for releasing a polished Electron app. The talk is especially useful if you're at the stage where you have a basic working app and you're trying to take it to the next level of polish and professionalism.

Watch here:

Slides here:

DC, another WebTorrent contributor, wrote a checklist of things you can do to make your app feel polished and native. It comes with code examples and covers things like macOS dock integration, drag-and-drop, desktop notifications, and making sure your app loads quickly.

The Electron 1.6.3 beta release contains initial support for the macOS Touch Bar.

The new Touch Bar API allows you to add buttons, labels, popovers, color pickers, sliders, and spacers. These elements can be dynamically updated and also emit events when they are interacted with.

This is the first release of this API so it will be evolving over the next few Electron releases. Please check out the release notes for further updates and open issues for any problems or missing functionality.

You can install this version via npm install electron@beta and learn more about it in the TouchBar and BrowserWindow Electron docs.

Big thanks to @MarshallOfSound for contributing this to Electron. 🎉

Touch Bar Example​

Below is an example of creating a simple slot machine game in the touch bar. It demonstrates how to create a touch bar, style the items, associate it with a window, handle button click events, and update the labels dynamically.

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

const { TouchBarButton, TouchBarLabel, TouchBarSpacer } = TouchBar;

let spinning = false;

// Reel labels
const reel1 = new TouchBarLabel();
const reel2 = new TouchBarLabel();
const reel3 = new TouchBarLabel();

// Spin result label
const result = new TouchBarLabel();

// Spin button
const spin = new TouchBarButton({
  label: '🎰 Spin',
  backgroundColor: '#7851A9',
  click: () => {
    // Ignore clicks if already spinning
    if (spinning) {
      return;
    }

    spinning = true;
    result.label = '';

    let timeout = 10;
    const spinLength = 4 * 1000; // 4 seconds
    const startTime = Date.now();

    const spinReels = () => {
      updateReels();

      if (Date.now() - startTime >= spinLength) {
        finishSpin();
      } else {
        // Slow down a bit on each spin
        timeout *= 1.1;
        setTimeout(spinReels, timeout);
      }
    };

    spinReels();
  },
});

const getRandomValue = () => {
  const values = ['🍒', '💎', '7️⃣', '🍊', '🔔', '⭐', '🍇', '🍀'];
  return values[Math.floor(Math.random() * values.length)];
};

const updateReels = () => {
  reel1.label = getRandomValue();
  reel2.label = getRandomValue();
  reel3.label = getRandomValue();
};

const finishSpin = () => {
  const uniqueValues = new Set([reel1.label, reel2.label, reel3.label]).size;
  if (uniqueValues === 1) {
    // All 3 values are the same
    result.label = '💰 Jackpot!';
    result.textColor = '#FDFF00';
  } else if (uniqueValues === 2) {
    // 2 values are the same
    result.label = '😍 Winner!';
    result.textColor = '#FDFF00';
  } else {
    // No values are the same
    result.label = '🙁 Spin Again';
    result.textColor = null;
  }
  spinning = false;
};

const touchBar = new TouchBar([
  spin,
  new TouchBarSpacer({ size: 'large' }),
  reel1,
  new TouchBarSpacer({ size: 'small' }),
  reel2,
  new TouchBarSpacer({ size: 'small' }),
  reel3,
  new TouchBarSpacer({ size: 'large' }),
  result,
]);

let window;

app.once('ready', () => {
  window = new BrowserWindow({
    frame: false,
    titleBarStyle: 'hidden-inset',
    width: 200,
    height: 200,
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