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AbortController is your friend One of my favorite new features of JS is the humble AbortController, and its AbortSignal. It enables some new development patterns, which I'll cover below, but first: the canonical demo. It's to use AbortController to provide a fetch() you can abort early: Sorry, your browser doesn't support an inline demo. And here's a simplified version of the demo's code: fetchBut

Unit Testing React without Jest Jest is clearly a polished testing tool, but with the advent of Node.js 18, we really don't need it any more. Jest also has a huge surface area, is perhaps inexorably linked to Webpack, and needs its own binary—you can't just "run the tests" as a script. So it has some modern challenges. This blog post will teach you how to set up your code, rather than provide an a

Builtin Node.js Testing As of Node.js 18, which became stable in April 2022, you can test your backend code without installing any dependencies. This works because of the new node:test package, along with the existing node:assert package—which is from the very first releases of Node. Here's the tl;dr. First, write a script like this, naming it e.g., "test.js": import test from 'node:test'; import