Has anyone seen or written something like this?
I'm gravitating towards GraphQL now because strict parsing is built into it, so there is no need for all this boilerplate.
https://www.npmjs.com/package/@mojotech/json-type-validation
However, as I'm saying this, I wonder if I've been looking at this problem wrong. Since we already generate types from GraphQL schemas, maybe I should figure out how to use the same client side parser that's already in my GraphQL client, define a GraphQL schema for the types I'm interested in, and then just generate and use those types.
One thing that doesn't necessarily give me is the ability to define custom parsers corresponding to custom types. At least, I think most of that sort of thing is usually done server side with GraphQL.
So, thank you for the link and also the inspiration for considering an alternative.
I really would like to see nominal typing support in TypeScript. Currently, it's hard to validate a piece of data (or parse for that matter) once and have other functions only operate on that validated data. There are (ugly?) workarounds though [1].
[0]: https://github.com/colinhacks/zod [1]: https://gist.github.com/dcolthorp/aa21cf87d847ae9942106435bf...
You define a decoder schema, and then the resulting TS type gets automatically derived for you. You can then run data through the decoder, it will err if there's a mismatch, or return a value of the inferred type otherwise.