TypeScript 5.6 Beta is Awesome

Following on from a great update with 5.5, the latest 5.6 release adds even more quality of life improvements.

What's New in TypeScript 5.6?

TypeScript 5.6 is packed with quality-of-life improvements, heres my favorite new features:

1. Disallowed Nullish and Truthy Checks: Help catch the sneaky always-truthy conditions! (while allowing while(true) ofcourse) 👋
2. Side Effect Import Checks: No more silent failures on typos in your side effect imports statements.
3. Arbitrary Module Identifiers: Emojis in your imports? 🤔 (The real use is for language interoperability i.e wasm)
4. Enhanced Iterator Support: Iterator helpers updated to match javascript standards.
5. Strict Built-in Iterator Checks: BuiltinIteratorReturn can be undefined, so the type is no longer widened to any, allowing you to catch undefined and typos before they throw an error in prod.
6. Improved Override Checks: Behaviour change to show you if you've pointlessly overridden a method not on the base class.
7. The New --noCheck Option: Compile with errors as you itterate, combine with --noEmit on another terminal for checking. (Maybe dont do tsc --noCheck --noEmit though 🤷‍♂️)

Why You Should Care

These updates aren't just performance improvements (altough thats in there too!) – they're real problem-solvers. How many times have you spent hours debugging, only to find out it was a simple typo in an import? Or maybe you've wrestled with iterator types, trying to get them to play nice with your code? TypeScript 5.6 addresses these pain points and more.

As someone who's been using TypeScript for years, Its cool to see it still improving. The team at Microsoft, with the help of the open-source community have been addressing common pain points and introducing features that'll make our code more robust and our development process smoother.

How to use?

If you want to test out some of these features now, install the beta:

pnpm install -D typescript@beta