10 TypeScript Tips & Tricks for Advanced Developers

Unlock the full potential of TypeScript with these lesser-known gems

Photo by Mariana Yarritu on Unsplash

TypeScript has rapidly become the go-to language for developers like myself who are looking to improve JavaScript codebases by adding type safety, better tooling, and improved maintainability.

As the language has evolved and matured, TypeScript has picked up some hidden features along the way. In this article, we'll delve into 10 lesser-known tips and tricks that will help you unlock TypeScript's full potential.

1. Using keyof and Mapped Types to Dynamically Build Types

The keyof keyword provides a powerful tool for dynamically building types based on the keys of an existing type.

“The keyof operator takes an object type and produces a string or numeric literal union of its keys.”

— TypeScript Docs

Combined with mapped types, you can generate new types from existing ones, while preserving the original structure.

type Point = { x: number; y: number };

type NullablePoint = {
  [K in keyof Point]: Point[K] | null;
};