Eclipse Theia 1.43 Release: News and Noteworthy

November 2, 2023 | 5 min Read

We are happy to announce the Eclipse Theia 1.43 release! The release contains 40 merged pull requests and we welcome three new contributors. In this article, we will highlight some selected improvements and provide an overview of the latest news around Theia.

You don’t know about Eclipse Theia, yet? It is the next-generation platform for building IDEs and tools for the web or desktop, based on modern state-of-the-art web technologies. For more details, please refer to this article and visit the Theia website.

Further, we would like to remind you that TheiaCon 2023 is approaching. TheiaCon 2023 will take place as a 2-day virtual event on November 15th and 16th. The event is the perfect place to learn about news around Theia and its community. So get registered now!

The Theia 1.43 release is the first release candidate for the next community release 2023-11. So, if you plan to adopt the next community release, please verify the 1.43 release and report important issues for your use case!

If you are looking for a simple way to check out the new release, please download Theia Blueprint, which has just been updated to 1.43.

Eclipse Theia 1.43: Selected features and improvements

In the following, we will highlight some selected improvements in the new release. As usual, we cannot mention all 40 improvements. However, we will focus on the most notable changes as well as changes visible to end users. The corresponding pull requests are linked under the respective heading when applicable.

Remote SSH Development

Theia 1.43 adds support for remote development via SSH. This allows you to directly develop on a remote machine, virtual machine or container, all seamlessly from within your own Theia IDE instance. This is very useful, e.g., to just use the set-up of a remote machine without the need to re-create this yourself. Theia will basically augment an existing remote host with its IDE capabilities; more precisely, it will upload the Theia backend and then connect your frontend to it, all via SSH. You can then access the files and develop in the set-up of the remote host for development.

If you want to learn more about this feature, we recommend you register for TheiaCon 2023. There will be a talk by Mark Sujev “Embracing Remote Systems in Local IDEs” with more details about this.

Support for Test Controllers

Theia 1.43 adds support for TestControllers, a huge enhancement simplifying the work with tests in various languages. TestControllers detect tests in the Theia workspace and enable the user to execute them via a dedicated UI, including reviewing the results. The Theia API is also compatible with the VS Code extension API, so TestControllers can also be contributed via VS Code extensions. This allows the use of existing VS Code extensions, e.g., for Java, TypeScript or Playwright, that provide TestControllers for the corresponding language. For more details on this feature, please watch the following video. Thanks to Thomas Maeder for providing this nice demo video!

Support for VS Code extensions 1.82

The Theia 1.43 release is the final step in terms of compatibility with VS Code extensions. As you might know, you can use VS Code extensions in Eclipse Theia applications. This enables you to enhance your Theia-based application with a pantheon of features from a huge ecosystem of available extensions available for VS Code, e.g., via the openVSX Registry. VS Code extensions specify the minimum version of VS Code they require to run to ensure compatibility. The Theia release 1.43 raises the compatibility level to 1.82, which is only one month behind VS Code and allows the vast majority of extensions to be installed in their latest versions. This has been the case for the last six releases already. However, with 1.43, Theia implements the last feature in the VS Code API, that has been only stubbed before, the TestAPI. Therefore, Theia is providing the exact same feature set in the VS Code extension API as VS Code.

Lazy loading for localizations

Theia 1.43 adds support for lazy loading of language files. This is relevant if you build a product based on Theia and provide translations for several languages. In this case, the lazy loading will speed up the start-up time significantly, as localization files are now only loaded on demand. This change is part of the ongoing initiative to improve the Theia start-up time, which has already provided amazing results in previous releases.

As always, the 1.43 release contains much more than described in this article, e.g. several UI improvements and improved translations.

All these features and improvements (in total 40) were the result of one month of intensive development. Eclipse Theia follows a monthly release schedule. We are looking forward to the next release due next month, stay tuned! To be notified about future releases, follow Theia on Twitter and register to our mailing list.

If you are interested in building custom tools or IDEs based on Eclipse Theia, EclipseSource provides consulting and implementation services for Eclipse Theia as well as for web-based tools in general. Furthermore, if you want to extend Theia with features such as the toolbar or the test framework, EclipseSource provides sponsored development for Theia, too. Finally, we provide consulting and support for hosting web-based tools in the cloud. Get in contact with us to discuss your use case!

Jonas, Maximilian & Philip

Jonas Helming, Maximilian Koegel and Philip Langer co-lead EclipseSource. They work as consultants and software engineers for building web-based and desktop-based tools. …