Just 28 から数カ月後しか経っていませんが、Jest 29 がリリースされました。 Jest 28 ブログ記事で説明したように、アップグレードをできるだけスムーズなものにするために、このバージョンには破壊的変更がいくつか含まれています。

Today we're excited to announce that Jest is joining the OpenJS Foundation!

This change transfers ownership of the project from Meta to the Jest Core team via the OpenJS Foundation as an Impact Project. We’re grateful to Meta for creating Jest and all of their support over the years, and we look forward to the future of Jest as a project owned by the Jest community!

Check out the Meta Engineering blog and OpenJS Foundation blog announcements for more info.

Jest 28 is finally here, and it comes with some long requested features such as support for sharding a test run across multiple machines, package exports and the ability to customize the behavior of fake timers. These are just some personal highlights, and we'll be highlighting more in this blog post.

Additionally, as announced in the Jest 27 blog post last year, we have removed some packages that no longer are used by default from the default installation. As a result the installation size has dropped by about 1/3.

約1年前の Jest 26 のブログポスト内で発表したのは、2つのメジャーリリースでいくつかの破壊的変更を行った後、Jest 27 で新しいプロジェクトやスムーズな移行のために一部の設定をよりよいデフォルトに切り替えることでした。 これにより、Jest 28 のデフォルトの配布物からいくつかのパッケージを削除し、個別にインストール可能でプラガブルなモジュールとして公開する機会が得られます。 新しいデフォルト設定ではインストールサイズが小さくなるため、すべての人が恩恵を受けることができます。一方でこれらのパッケージが必要な人は、個別にインストールすることもできます。

Jest 27では、Jestの高速性、効率性、将来性を維持するためにmバージョン15に付属していた New Defaults for Jest 以来の大きなデフォルト設定の変更が行われました。 この記事では、これらのデフォルトの変更やその他の注目すべき変更点について説明しますが、その前に、エキサイティングな新機能についてご紹介します！

We are excited to present the new Jest website!

The Jest site was upgraded from Docusaurus 1 to Docusaurus 2, and is an early adopter of the newly released Docusaurus 2 i18n support.

So, what's new exactly?

When we started rebuilding Jest five years ago our goal was to provide a batteries-included zero-configuration test runner that is approachable for beginners, extensible for almost all testing use cases and scalable to large projects. One of the instrumental releases was Jest 15 which tied everything together and provided good defaults that allowed people to run Jest often without any setup. However, this approach has a big downside as Jest installs a lot of dependencies into your projects that you may not need.

We are now beginning to address this shortcoming and are working on reducing Jest’s install size while keeping it approachable and extensible. We have made the following breaking changes in Jest 26:

Jest 25 is laying the groundwork for many major changes in the future. As such, we kept breaking changes to a minimum, but internal architecture changes may require attention during the upgrade. The main changes are an upgrade of JSDOM from v11 to v15, 10-15% faster test runs, a new diff view for outdated snapshots and dropped Node 6 support.

There has been more than 200 commits since Jest 24.9 by more than 80 different contributors, so as always, take a look at the changelog for a full list of changes.

Today we are happy to announce the next major release of Jest - version 24! It's been 4 months since the last minor release, and 8 months since Jest 23, so this upgrade is a big one, with something for everyone! Highlights include built-in support for TypeScript by upgrading the Jest internals to Babel 7, fixing some long-standing issues with missing console output and performance issues when computing large diffs, and a brand new sparkling website. ✨

For a full list of all changes see the changelog.

Jest is maintained by a community of open source contributors and Facebook employees.

Our open source contributors work on behalf of the community to create new features, fix bugs, and maintain the issue backlog. Facebook employees do the same, focused on the problems specific to Facebook's scale, and run all proposed releases on Facebook's enormous test suite before publishing.

All of us do our part to make testing delightful.

At the Jest Summit we announced the Jest Open Collective. This is our way to help support the efforts of the open source Jest community. To be absolutely clear: Facebook employees cannot benefit from the Jest Open Collective. The collective's sole purpose is to support the open source side of the Jest community.

In this post we'll outline what the Jest Open Collective is, the structure, and the goals we have.

Today we are excited to announce Jest 23, our largest major release to date! Together with over 100 contributors, we've shipped a ton of features and bug fixes. Thank you to everyone in the community for helping make JavaScript Testing Delightful.

We would also like to welcome both Babel and webpack to the Jest community! After converting from Mocha to Jest 23 Beta, webpack saw their total test suite time reduced 6x from over 13 minutes to 2 minutes 20 seconds. #blazingmeansgood

Here's are some of the Jest 23 highlights and breaking changes.