autowire

Might be worth looking into Autowire [0]. Runs Scala code locally, compiles your API through ScalaJS, allowing you to write your app all in one language without exposing the business logic to the client. [0] https://github.com/lihaoyi/autowire

You could make some of the same arguments against prop types - what if you miss them, what if they are incorrect (too narrow). Regarding third party libraries, with prop types you are effectively writing your own bindings to the parts of those libraries that happen to go through your props, except you fail far away from where the error is produced. Prop types are also a very ad-hoc solution to a very general problem. Why are props for UI components especially deserving of type checking? What about the rest of your application code? Event your components' state is not worthy of type checking? With JS or typed-JS languages like Typescript or Flow you will never get full type safety (Flow is better at safety than TS if you're interested). For me the solution is to either go 80% of the way for 20% of the effort with those languages, or go ful

If you don't trust your JSON input to be of proper type, you should validate its type immediately when you receive it, before you start fanning it out to your code. Spreading this work to prop types just makes it harder to keep track of it, and harder to find the source of the problem. Besides, some of that broken JSON data might never even be passed through proptypes (e.g. if that data lives only in a component's state). Also, there are compile-time solutions to this in some compile-to-JS languages, e.g. like https://github.com/lihaoyi/autowire for Scala.js

You could take a look at the stuff that li haoyi does: https://github.com/lihaoyi/autowire (because you mentioned rpc, but also his other stuff. His output is amazing).