As Dart developers, we’re no strangers to asynchronous programming and the power of Futures. In the past, when we needed to wait for multiple futures concurrently, we relied on the Future.wait([]) method, which returned a List<T>. However, this approach had a significant drawback: we had to manually cast the results to their desired types, which could lead to verbose and error-prone code.

final results = await Future.wait([
  Future.value("andrew"),
  Future.value(1984),
]);
expect((results[0] as String).toUpperCase(), "ANDREW");
expect((results[1] as int).isNegative, false);

Fortunately, there’s a more elegant solution that leverages the power of extensions and async/await syntax: the zipWith extension method.

Introducing zipWith

The zipWith extension method allows you to combine the results of two futures into a typed tuple, eliminating the need for manual casting. Here's how it works:

final (name, year) = await Future.value("andrew")
    .zipWith(Future.value(1984));
expect(name.toUpperCase(), "ANDREW");
expect(year.isNegative, false);

In this example, we’re combining the results of two futures: one that resolves to the string “andrew” and another that resolves to the integer 1984. The zipWith method returns a tuple (T, T2) where T is the type of the first future, and T2 is the type of the second future.

But wait, there’s more! You can even chain multiple zipWith calls to combine the results of three or more futures:

final ((name, year), married) = await Future.value("andrew")
    .zipWith(Future.value(1984))
    .zipWith(Future.value(false));

expect(married, false);

In this example, we’re combining three futures, resulting in a nested tuple ((T, T2), T3).

Under the Hood

So, how does zipWith work its magic? Here's the implementation:

extension FutureZipX<T> on Future<T> {
  Future<(T, T2)> zipWith<T2>(Future<T2> future2) async {
    late T result1;
    late T2 result2;
    await Future.wait([
      then((it) => result1 = it),
      future2.then((it) => result2 = it)
    ]);
    return (result1, result2);
  }
}

Wrapping Up

By embracing the power of zipWith, you can write cleaner, more expressive code when working with multiple asynchronous operations. No more manual casting or fiddling with List<dynamic> – just concise, type-safe tuples that make your code easier to read and maintain.

So, the next time you find yourself juggling multiple futures, give zipWith a try and experience the joy of streamlined asynchronous programming in Dart.

See Also

Flatten nested tuples: https://gist.github.com/yongjhih/89a199ec14127f92a001d2e15e8a32ac

Now that the dust has settled on the news of layoffs at Google, let’s take a quick look at what this means for Flutter.

Unnecessary drama

The news of layoffs in the Flutter team had no detail — was 1% of the team effected or 50%? It was not clear.

Without concrete information, the rumour mill went into overdrive (perhaps not without good reason…more on that later).

Eventually, Michael Thompson from Google clarified the situation. Basically the changes to Flutter effected some of the DevOps roles, but otherwise the team size stays the same.

TL;DR — the news headlines created a lot of unnecessary drama but the reality is actually that nothing substantive is changing.

Google creates FUD

What this week has showed (again), is that Google has created a lot of mistrust in it’s commitment to products and projects.

Google is really damaging it’s brand with all the high profile projects being killed which is exacerbated by the volume of small ones — see https://killedbygoogle.com/.

Whilst the Flutter technology is strong, the community vibrant and the real world backing plentiful, Google is making is much harder for companies to invest in building Flutter-based software.

Too big to fail?

Despite Google’s efforts to scare the Flutter community, our view is that Flutter has crossed a threshold that makes it too big to fail.

Let’s just look at who is betting on Flutter:

Toyota is using Flutter to build its next gen Infotainment Systems that will be in thousands of cars across the globe. Read more.
Ubuntu 23.04 shipped with a new installer tool written in Flutter. Canonical (the company behind Ubuntu) has indicated that it would use Flutter as the technology for future desktop app development. Read more.
Google Earth for mobile and web was rewritten in Flutter, another signal that Google’s engineers are betting on Flutter. Read more.
Google Pay on iOS and Android was implemented using Flutter. Another sign of Google’s commitment. Read more.
Google Classroom rebuilt it’s mobile apps using Flutter having been inspired by what the Google Pay team were able to achieve. Read more.
Alibaba built Xianyu (a 50+ million user marketplace) using Flutter
eBay built the eBay Motors mobile app using Flutter. Read more.

The investments in Flutter from inside Google and from the community are a good indicator that Flutter has survived it’s infancy.

Slowing adoption

Whilst we believe that Flutter is here to stay, there are questions about the rate of adoption.

On the Flutter showcase page, you will see the projects from the biggest brands are from 2021. Canonical’s bold claims that they are “making Flutter the default choice for future Canonical mobile and desktop apps” have not yet translated into reality.

The Flutter leadership team (e.g. Eric Seidel, Tim Sneath) that achieved initial success have moved onto other companies or projects.

Google is great at getting projects into the world and creating initial adoption. However, it has proven itself less able to stick it out during the long hard road to widespread adoption.

Google needs to double-down on Flutter through this adoption phase — as it did with Angular, Android, Golang and many other great contributions.

Will it do so? That’s the question looms large in light of the latest round of layoffs.

If the Flutter team is allowed to continue on it’s current trajectory, there are signs that they will continue to make good progress. For example see this Reddit post: Headspace (65 million users) is migrating to Flutter.

Our prediction

Our general expectation is for the mobile development landscape to shift towards a more efficient model for building across multiple devices. Flutter will be an importat part of that story on mobile.

However, we see great opportunity for Flutter to also flourish outside the mobile world.

Flutter could be key to widespread adoption of WebAssembly, a way to run compiled applications in the browser — see Figma’s WebAssembly story. The Flutter team already have Wasm support in Beta.

At Snapp, we are also betting on Flutter as a modern replacement to Qt for UI development for embedded software. The Snapp Embedded project from our sister company, Snapp-X is building the tooling to make this possible and we are already working with one of the world’s largest manufacturers of white goods (freezers, ovens, washing machines) to build device UIs using Flutter.

For more widespread adoption, Flutter will need to show how it is truly cross platform with massive code reuse across mobile and web. This is one of the biggest advantages over ReactNative — the incumbent for non-native mobile development.

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