One way ticket to TypeScript hell... and back

Today’s issue: The Angular blood feuds of yesteryear, “slopsquatting”, and a new shadcn tool for measuring the sharpness of your jawline.

Welcome to #506.

---

One way ticket to TypeScript hell… and back

Remember when our close personal friend Cheng Lou “crawled through the depths of hell” to bring us Pretext, the text measurement library that singlehandedly fixed one of the browser’s oldest problems?

So it turns out Cheng has no idea we exist, but he’s back again with Freerange, a zero-API tool that statically deduces the numerical range of every number in your TypeScript codebase.

Why is that helpful? Vanilla TypeScript™️ is great at telling you if something is a number but useless at telling you which number. That wasn’t a huge deal back when humans were writing artisanal layout math and eyeballing width: number in the browser, but it’s a pretty big problem when your agents are cranking out thousands of lines of code that you’ll never read because you’re busy watching Boy Meets World reruns and wondering how we’re closer to the year 2050 than 2002.

Freerange actually tracks all the numbers. It follows every value through your code at compile time and flags anything that could blow up downstream. And you never have to run the code or write an annotation.

Let’s break it down:

• It catches bugs types can’t. Let’s say you’ve got a progress bar computing (value - start) / (end - start). If start === end, you’re now piping Infinity through your entire UI. Freerange catches it at build time, along with NaN leaks and out-of-bounds array reads.

• It’s just TypeScript. It uses the official TS API, respects your tsconfig, and turns the humble console.assert into a compile-time proof. fr --audit prints every function’s inferred contracts plus refactor suggestions.

• It’s built for coding agents. Freerange only analyzes a deliberate subset of TS, which would’ve been a dealbreaker back when humans had to do the refactoring. But agents will happily reshape your calculations into the provable subset.

Bottom Line: Cheng says that he spent months and billions of tokens to create this “first step in our long, long collective journey to turn vibe coding into proof engineering.”

And as we all know, a journey of 1,000 miles begins with a single clanker.

---

2x faster GitHub runners that cost 60% less

Blacksmith is a dead simple, drop-in replacement for GitHub runners that instantly starts faster, runs faster, and saves you a bunch of money.

How does that work?

• 2x faster hardware – They run your GitHub Actions on bare metal gaming CPUs with the highest possible performance

• 4x faster cache downloads – They co-locate your cache artifacts in the same data center where your jobs are running

• Fully observable – So you can quickly see what’s happening in your CI pipeline when something goes wrong

Get 3,000 free minutes to try it out – and see why over 30,000 developers use Blacksmith at companies like Supabase, Clerk, and Mercury.

---

1. Tom Bedor shared how the arguments against open source AI are very bad. But what about the argument that banning open source AI helps to enrich the Epstein class protect the children?

2. shadscan gives deterministic UI audits for React shadcn components. Not to be confused with a ChadScan, which is what they call CAT scans that measure the sharpness of your jawline.

3. Wispr Flow is the smart, voice-to-text tool that *actually works* across any app and device. Just speak naturally when you want to write an AI prompt, PR description, or Slack message, and Wispr Flow turns it into clean, formatted text that’s ready to send. [sponsored]

4. Ahmed Darwich wrote about what’s new in Postgres 19 so that I didn’t have to. Thank you for your service 🫡.

5. Sarah Gooding wrote about how five frontier LLMs hallucinated the same nonexistent package names, 53 of which were still unregistered on PyPI and npm, creating free real estate for slopsquatters.

6. Only idiots write manual tests – modern engineering teams like Notion, Dropbox and LaunchDarkly use Meticulous to maintain e2e UI tests that cover every edge case of your web app. [sponsored]

7. Canvas UI is a library of “tasteful” html-in-canvas and WebGL components that are all framework agnostic. Because we’re not gonna do anything that makes you feel uncomfortable. The key word is tasteful.

8. Angular is switching to a yearly release cadence to provide greater API stability for coding agents and because developers don’t really get in blood feuds arguing about Signals anymore.

9. Convex’s reactive backend platform is built to keep up with your agents because it gives you a database, functions, workflow, sync, search, file storage, and more. All TypeScript, zero glue. [sponsored]

10. Claude Opus 5 just dropped so the scary open source models can’t hurt you anymore.

11. Jamie Davenport wrote about his team’s experience pairing TSRX with TanStack Start, including the good stuff and the three bugs they filed.

12. A North Korean campaign used fake coding interviews to steal developer credentials by hiding malware inside SVG flag images. Yet another reason to remain funemployed.