Matt Pocok

TypeScript boosts productivity but faces pitfalls like type mismatches, null values, & puzzling errors. Learn to spot & solve these for swift progress.

Get productive building applications with React and TypeScript with our interactive guide on React's types - from component props to useRef.

Free interactive video tutorial that will help you get started with TypeScript.

Zod is a TypeScript-first schema declaration and validation library. In this tutorial, Matt Pocock has prepared a set of exercises that will help you level up.

Understand how Type Predicates work in TypeScript, using an example of filtering a mixed array of elements.

TypeScript 5.1 is out! With important updates to React Server Components and some small usability updates.

How to name your types in TypeScript can be a tricky business. Matt takes you through his opinionated heuristics for how to decide.

When should you use return types in TypeScript? The use cases are narrower than you might think...

TypeScript 5.0 beta brings a bunch of exciting features, including const annotations and decorators.

React's useState can behave in slightly unexpected ways in TypeScript - sometimes giving you undefined when you least expect it.

I often find conditional types SUPER hard to read. Here's how to get a better mental model for assignability in TypeScript.

A simple function - returnWhatIPassIn - can be enough to stump many newbie TypeScript devs.

Still struggling with infer? How about this - you can use it in combination with string literals to manipulate keys of objects.

Accessing object values and array members is MUCH more powerful in the type world than it is in the runtime world.

This one little tip has saved me hours of refactoring time. Passing string | undefined instead of ?: string ensures that ALL call sites must be given a value.

This mental model is INCREDIBLY useful for all sorts of intermediate-advanced typings.

If you're thinking about putting a TypeScript package up to NPM, you should be considering preconstruct.

You can do some really, really neat stuff with assertion functions inside classes.

You can DRY up your generics code MASSIVELY (and improve perf) by assigning local variables to default generic slots.

It can be hard to know when to reach for generics. I'll show you when you need them.

Mapping over a union type can feel tricky to conceptualise. But actually, TypeScript does it all for you - using Distributive Conditional Types.

The "noUncheckedIndexedAccess" is the most awesome config option you've never heard of.

You can use generics to dynamically specify the number, and type, of arguments to functions.