Skip to content

This.JavaScript: State of Frameworks-RxJS Update

This article was written over 18 months ago and may contain information that is out of date. Some content may be relevant but please refer to the relevant official documentation or available resources for the latest information.

Hosted by This.JavaScript, an online event where developers learn about the latest news in JavaScript, State of Frameworks and Libraries covered all the breaking news in the world of frameworks.

On Feb. 19, State of Frameworks speakers, including many of the best and brightest from the development world, gave us updates on all things frameworks.

Here’s some of what Ben Lesh, RxJS lead, had to say about what’s coming up at RxJS.

Ben Lesh — RxJS Lead, Angular Team — @benlesh

Bug Fixes in 6.4.0

RxJS 6.4.0 was recently released. Many of the changes were minor bug fixes, but there were a few important changes. Several of these were related to TypeScript.

RxJS 6 has always been targeting TypeScript 2.8 and higher. This was the first time RxJS developers used a specific 2.8 feature, however. Users who are using 2.7 may have had trouble and may need to upgrade TypeScript.

Users of the shareReplay feature used to experience a bug in the counting feature, in which everyone could unsubscribe from it but the source would keep going. A new update to shareReplay in RxJS gives the ability to opt out of that. Now, if everyone unsubscribes, it unsubscribes from the source.

For the new version of RxJS, we used a feature from TypeScript 2.8 — conditional types — which provides a way to pull a generic type out of another generic type. This can be used in various spots to fix previous issues for users of Redux Observable.

Also, users have been asking for a long time for a takeWhile inclusive option, which is now available.

Lessons for the Future

The RxJS Core team learned a few major lessons from this last round of changes and updates.

RxJS 7 will remove deprecated APIs and update the types to support TypeScript 3.0 and higher. This puts RxJS in a good position to move over to the smaller version of TypeScript.

The smaller version of RxJS will be Rx 8, while RxJS 7 will see more improvements in types. Well over 60% of RxJS users use TypeScript, so it’s crucial to get that right — sometimes a difficulty in a library that’s functional like this.

This Dot is a consultancy dedicated to guiding companies through their modernization and digital transformation journeys. Specializing in replatforming, modernizing, and launching new initiatives, we stand out by taking true ownership of your engineering projects.

We love helping teams with projects that have missed their deadlines or helping keep your strategic digital initiatives on course. Check out our case studies and our clients that trust us with their engineering.

Let's innovate together!

We're ready to be your trusted technical partners in your digital innovation journey.

Whether it's modernization or custom software solutions, our team of experts can guide you through best practices and how to build scalable, performant software that lasts.

Prefer email? hi@thisdot.co