type-fest VS type-challenges

Related: https://github.com/sindresorhus/type-fest/blob/main/source/o...

Typescript doesn’t natively provide an Opaque type that we can use to define a string that has already been localized. If the data looks like a string, Typescript will consider it a string. We can however use utility types that simulate opaque types, like the Opaque definition in type-fest:

With these powerful features, you can create dynamic and expressive types. One last thing I want to mention before moving on, is that you can install libraries with which you can add more types to your project like type-fest or utility-types. These libraries contain a lot of useful types that you can use in your project.

Also, it’s not as restrictive as mutability tools — if you know what you are doing and want to ignore this limitation for a particular case, you can apply the -readonly modifier or the Writeable type from type-fest or ts-essentials.

Remember you can derive one type from another type so you can make sure they don't diverge. SetOptional type util

Some folks have built whole SQL databases and DSL compilers in the TS type system. These tend to be toy projects with disclaimers not to use them. But the type system being Turing complete[0] (for better or worse), pretty much whatever you can imagine. This project[1] is one I actually return to frequently for practical ideas.

0: https://github.com/microsoft/TypeScript/issues/14833

1: https://github.com/sindresorhus/type-fest

Have a look at SetRequired and SetOptional in type-fest

Try the Exact method provided by Type Fest, looks like it does what you're looking for

This is a fairly common scenario and available via libraries like type-fest or implementable with a couple lines of code.

View on GitHub

For those who want to improve their type level skills, I highly recommend this repository for learning by doing: https://github.com/type-challenges/type-challenges.

I'm very like typescript and I always try to learn something interesting there. I thought that it is impossible to know the length of the string in typescript, but I was wrong. Today during solving typescript challenge I found a way to do it. If you don't know about typescript challenges, you can read about it here, it is a very interesting project, and I highly recommend you to try it, if you, like me, obsessed with typescript.

For those wonder why you don’t need a CS degree, I invite you to solve the type problems here https://github.com/type-challenges/type-challenges. No degree needed and if you can solve those problems with ease (as really understand the problems), you can work on any problems in any business.

It's not really a major usage but I think it would be cool to see if a coding model could be fine-tuned to take in a prompt of instructions and output a valid Typescript type solution (like in https://github.com/type-challenges/type-challenges)