Scala Test-State VS scalajs-react

It actually been rock-solid for many, many years now! I've built quite a few things with it and introduced it to teams who picked it up very quickly and with no major problems. I've never had any production problems with it EVER and I've been living and breathing it pretty much every day for ages now. It's very, very unit testable (oh! check out Scala Test State if you're interested in really powerful and concise Scala.JS testing) so it's nearly trivial to have to very well tested webapp, including mouse clicks, key presses, whatever you want. Awesome awesome stuff and the Scala.JS team deserve some kind of tech Nobel prize imo. It's been a game changer for me.

Then there's scalajs-react, which can be integrated with existing React ecosystem, but it's just sooo compex: macros, 5-6 type parameters, hundreds and hundreds of cryptic types. We decided to stick with TypeScript instead.

Or the OG React Scala.js library: https://github.com/japgolly/scalajs-react

Japgolly has put a ton of time and care into https://github.com/japgolly/scalajs-react which is a complete React binding in scalajs. This paired with something like Diode (https://github.com/suzaku-io/diode) and you get a full frontend solution in scalajs.

We've got server-side rendering with scalajs-react and scala-graal. Here's a tutorial if anyone's interested. What's really cool about scala-graal is that it has some pretty cool caching so that even with dynamic inputs, you can render pages in nanoseconds (as opposed to 10+ or even 100+ ms).

You can use React with Scala.js, and also most other common JS libraries. Or you can use a Scala.js specific library like Laminar, which I haven't tried myself but it looks nice.

I don't have a lot of experience with it, but many seem to be very pleased with it. Interop with JS is good and you can use React and other common JS libraries, but there is also Scala.js specific frameworks like Laminar.

https://github.com/japgolly/scalajs-react is pretty heavily used as well, and fairly active as a project. In short, building it off of that wouldn't be a huge risk over typescript, and might even be a net win in the long run, as you could re-use some stuff from the backend in the front-end.