yup

I think the main concern for frontend validation was before HTML5 came along with validation attributes. You can easily produce HTML input validation attributes from a Yup schema for example by using its serialization feature (https://github.com/jquense/yup#schemadescribeoptions-resolve...). Here is an example from some silly code I wrote a while back testing htmx with deno https://github.com/dsego/ssr-playground/

https://deepkit.io/ may be of interest to you! It deeply patches the TS type compiler to make all types visible at runtime, enabling a lot of annotation-style workflows and dependency injection possible completely within the type annotation system: https://docs.deepkit.io/english/runtime-types.html Previous discussion: https://news.ycombinator.com/item?id=31663298 - it's downright mindblowing that all this seems to be the work of primarily a single developer. For a less intrusive solution, https://github.com/jquense/yup is a great library to reach for whenever you're defining the shape of a network-transmitted object and don't want to introduce compilation stages.

Check out yup* https://github.com/jquense/yup

Personally I really enjoy Typanion [0] since it's very similar to Yup [1] which I previously had extensive experience with. You can find more alternatives and a lengthy discussion about the whole problem space and its history in [2]. [0] https://github.com/arcanis/typanion [1] https://github.com/jquense/yup [2] https://github.com/microsoft/TypeScript/issues/3628

Not quite the same, but reminds me a bit of yup (https://github.com/jquense/yup)!

For React forms and validation the combo of Formik and Yup is quite nice. Formik takes a schema prop specifically for integration with Yup, it's covered in the docs. https://github.com/jaredpalmer/formik https://github.com/jquense/yup

...and its lightweight counterpart for the browser: https://github.com/jquense/yup

I've used it in a couple of form-heavy production projects and found it to be good, I find the API pretty easy to work with and it handles things like async validation pretty nicely (I use it in combination with yup for validating the form object: https://github.com/jquense/yup). I can honestly say it has almost made working with forms enjoyable ;) A definite high point of my time with it was when a requirement came along to allow users to resume signup - because all the form state was in the Redux store already, it was simply a case of serializing that and putting it in localStorage (or wherever), then reloading it as the initialState. There are performance issues to be aware of if your form gets too large, caused by the "top down re-render" effect of having the top level ReduxForm HOC connected to the form state and therefore re-renderi