Gabriel Vergnaud

Release v5.7.0 · gvergnaud/ts-pattern New feature Exhaustive callback By default, .exhaustive() will throw an error if the input value wasn't handled by any .with(...) clause. This should only happen if your types are incorrect. It is ...

Release note 👇
github.com/gvergnaud/ts...

A new version of TS-Pattern is out 🚨

You can now customize the fallback behavior of `.exhaustive()` if the runtime value you get is unexpected.

upgrade 👉 npm i ts-pattern@5.7.0

Love it! These sound effects are just perfect ❤️

And here is a TypeScript Playground with the full code snippet
👇

www.typescriptlang.org/play/#code/F...

Loops with Mapped Types — Type-Level TypeScript Most TypeScript code is about transforming objects, so we often end up with many object variants in our codebases. Let’s learn how to generate object types by looping through the keys and values of ex...

I also have a full chapter about advance uses for Mapped Types in my TypeScript course, check it out: type-level-typescript.com/mapped-types

Mapped Types are a super powerful feature that you can learn about in TypeScript docs: www.typescriptlang.org/docs/handboo...

Here is another reason I like Type Catalogs.

They can easily be transformed with Mapped Types!

Full code snippet in thread 🧵👇

You need to understand how unions distribute over conditional types to fully get why `Extract` works. Its definition can be somewhat cryptic:

yea ultimately unions and catalogs encode the same information so either option works!

To extract a member of a discriminated union, I find that using the builtin Extract utility is the simplest, but I've noticed that the way Extract works isn't immediately intuitive to most people

I started using this pattern in one of my codebases a year ago and never looked back.

If you are also a heavy user of unions of objects, give it a try!

And lastly, it makes writing generic function types so much easier!

No need for pesky `Extract`s or `Exclude`s 🔥

Secondly, you can generate sub-unions super easily:

Firstly, having a catalog greatly decreases the number of type imports you need to make:

Pro tip: Don't write your #TypeScript union types by hand, use a Type Catalog instead!

Why are Type Catalogs better?

Find out in the thread 🧵 👇

A new TS-Pattern release is out!

👉 Prevent passing impossible patterns to `isMatching` when used with 2 parameters.
👉 `P.infer` behaves better when used in an argument position.

just run `npm i ts-pattern@v5.6.0` in your project 😊

Release note: github.com/gvergnaud/ts...

Type-Level TypeScript is on sale for Black Friday! 🚨

You can get it for 25% off! It's only 74$ to get lifetime access to all course materials.

👉 type-level-typescript.com

Enroll to learn how to craft and transform #TypeScript *types* with the same ease you handle JavaScript values every day!

Template Literal Types are awesome.

If you concat `number` and a union of time units, you have a human readable AND type-safe way to provide time values! 👇

Thanks @ayc0.github.io! ❤️🙌

How to get optional keys from object types in TypeScript? — Type-Level TypeScript Let's build a reusable type helper to get all optional keys from an object type in TypeScript.

Hey friends 👋

Trying out @bsky.app, looks great so far!

I'll post TypeScript and programming related things.

to get started, here is an article I wrote a couple of weeks ago explaining how to get optional keys from object types 🤗

type-level-typescript.com/articles/how...