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This Week in Dart - Issue 16

Hello fellow Dartisans! Welcome to the sixteenth issue of This Week in Dart! This Week in Dart's aim is to be a useful collection of changes and news from across the Dart ecosystem and its surrounding community.

To contribute to this and future issues, feel free to contribute on GitHub or suggest content for next week on GitHub discussions.

To discuss this week's issue, feel free to join us on the Unofficial Dart Community Discord in the #this-week-in-dart channel.



Multiple deprecations to error types will be made in dart:core alongside Dart 2.19:

You should remove and migrate all use cases of these now deprecated classes and constructors.

Community updates



Learning materials

Project releases

Project updates

Dart SDK updates

43 unique authors have contributed 150 commits to the Dart SDK in the past week.

The following are some handpicked, interesting changes:

Keep in mind, none of these changes are guaranteed to eventually land in a stable release.

Language updates and discussion

This week saw the patterns proposal be accepted to be implemented in a future Dart version. Beyond that, the 2.16 version of the patterns feature specification was released updating the syntax of switch expressions to eliminate case and default.

Beyond that, the 1.1 version of the in-progress sealed types feature specification was released. To avoid unnecessary breaking changes, the sealed keyword is no longer a built-in identifier, now relying on the context of preceding mixin or class.

To learn more about and contribute to discussion of these and other potential changes to the Dart language, visit the Dart language repository.

Package of the week

The package of the week is mason_cli and the rest of the mason ecosystem.

package:mason_cli allows developers to create and consume reusable templates called bricks.

The CLI tool has support for creating new bricks, searching for existing breaks, installing and removing bricks, and even bundling bricks like is done in package:very_good_cli.

To find or share bricks, they even have a special site and platform, BricksHub.

To learn more about the mason ecosystem and how to use the CLI, see its page on or Felix Angelov's recent introduction at Flutter Vikings.

Dart's package ecosystem is growing fast, and we want to help foster that growth. If you know of any great open source projects, let us know by suggesting a package on GitHub discussions.

Upcoming events

Check the Flutter Meetup Network and the Dart Language tag on Meetup to find an event near you or online and connect with other Dart developers!

Let us know about future events on the events discussion board to include here!

Quotes and notes

Share quotes and comments you see and hear about Dart on our quotes discussion board for future inclusion!

If you like @typescript (I do), then you'll LOVE @dart_lang 💙

—@craig_labenz on Twitter

I like the enhanced enums

—@Skiotic on the Dart Community Discord

Dart jobs

If you know of any jobs which use or are related to Dart, let us know in the Job postings for Dart discussion board, and we will be happy to include them here!