Microsoft Announces TypeScript 5.8

Today we’re excited to announce the release of TypeScript 5.8!

If you’re not familiar with TypeScript, it’s a language that builds on top of JavaScript by adding syntax for types. Writing types in our code allows us to explain intent and have other tools check our code to catch mistakes like typos, issues with null and undefined, and more. Types also power TypeScript’s editor tooling like the auto-completion, code navigation, and refactorings that you might see in editors like Visual Studio and VS Code. In fact, TypeScript and its ecosystem powers the JavaScript experience in both of those editors as well!

To get started using TypeScript, you can install it through npm with the following command:

npm install -D typescript

What’s New Since the Beta and RC?​

Since our beta release, we have had to pull back some work on how functions with conditional return types are checked. Based on some of the limitations and changes we wanted to make, we decided to iterate on the feature with the goal of shipping it in TypeScript 5.9. However, as part of this work, we added more granular checks for branches within return expressions. This enhancement was not documented in the beta post, but will remain in TypeScript 5.8.

No new major changes have been added since the release candidate.

What’s Next?​

The next version of TypeScript will be TypeScript 5.9, and we’ll have more details through an upcoming iteration plan on our issue tracker. That will have precise target dates and more details on upcoming features that we plan to work on. In the meantime, you can try out early versions of TypeScript 5.9 today by installing our nightly builds from npm with npm install typescript@next, or by using the VS Code TypeScript Nightly extension.

Until then, TypeScript 5.8 is here and ready to use, and we’re excited for you to install it today! We hope that this release makes your day-to-day coding a joy.

Happy Hacking!

– Daniel Rosenwasser and the TypeScript Team