Lightnews — Scholar-powered news

Michael Shilman

@shilman.net

Tabs vs spaces? Spaces!!

@reinhold.is and I discovered that when it comes to AI codegen using Claude Sonnet 4.5, spaces consume fewer than half the tokens (= half the cost) as tabs.

(Curiously, the difference is much smaller on GPT/Gemini/Deepseek, which all seem to use same tokenization.)

"ai-tokenizer" output for similar code generated by Claude Sonnet. The left example uses tabs and consumes 11,653 tokens. The right example uses spaces and consumes 5,607 tokens. Weird!

November 13, 2025 at 10:25 AM

Michael Shilman

@shilman.net

20y ago I helped build Microsoft Tablet PC, an ambitious project that never fulfilled its promise. Kudos to @supernote.com for creating a truly satisfying digital ink experience. Got mine this week and it’s a dream come true!!!

November 8, 2025 at 4:14 AM

Michael Shilman

@shilman.net

Being able to ask for something and get ballpark code is just so good. Python notebooks integrated into VSCode let me tweak the code and see the output interactively.

Code to plot a collection of data features ("dev", "StoryCount", "ErrorRatio", etc.), and the resulting bar chart visualization in a Python notebook.

August 27, 2025 at 7:09 PM

Michael Shilman

@shilman.net

Full speed ahead on component testing for React Server Components!

✅ vitest-plugin-rsc canary now on npm
✅ vite RSC refactor for testing support
✅ @nextjs.org context providers
✅ Notes app demo with tests

👉 github.com/kasperpeulen...

React server component testing example for Next.js notes app: "note editor saves note and redirects after submitting note"

August 7, 2025 at 5:47 PM

Michael Shilman

@shilman.net

This test runs an entire RSC stack in the browser. Because server & client are co-located, it’s easier to write/mock, much faster, and less flaky than the E2E equivalent.

A component test that renders a `Users` server component, clicks on the like button, and then asserts that number of likes in the database has been incremented.

July 28, 2025 at 7:43 AM

Michael Shilman

@shilman.net

2025 has been my worst health year ever and we’re not even halfway through it. Here’s the latest fiasco! Thankfully wrist is recovering on schedule…

X-ray of my broken wrist with titanium plate and pin. Ouch!

May 8, 2025 at 3:37 PM

Michael Shilman

@shilman.net

All of this was complicated by the birth of my daughter. I no longer had 20 hour days to work through problems as they arose. Not to mention a global pandemic!

February 16, 2025 at 5:51 AM

Michael Shilman

@shilman.net

Happy lunar new year!! 🧧🐍🍊

January 31, 2025 at 3:44 PM

Michael Shilman

@shilman.net

When it comes to writing stories, improved typesafety and autocompletion are @storybook.js.org's top user requests. We've also heard our "play" function feels too different from the rest of the testing ecosystem.

We want to address this feedback in Storybook 9. 🧵

Code snippet for new CSF typesafe factories and test proposal.

const meta = config.meta({ component: Button })

// 1. Type-safe story factories "arrange"
export const Primary = meta.story({
args: { label: 'Primary', onClick: fn() }
})

// 2. Jest-style tests "act" and "assert"
Primary.test('handles clicks', async ({ canvas, args }) => {
await userEvent.click(canvas)
await expect(args.onClick).toHaveBeenCalled()
});

January 12, 2025 at 10:12 AM

Michael Shilman

@shilman.net

The survey results are distorted compared to previous years. Positive sentiment libraries lost ground in 2024 and negative sentiment libraries gained ground. Would you say that people like popular libraries less this year and unpopular libraries more?

State of JS 2024 chart that shows how the new survey UI affected the survey outcome. X-axis = sentiment, Y-axis = popularity. Most positive sentiment libraries moved left and most negative sentiment libraries moved right.

December 29, 2024 at 12:49 PM

Michael Shilman

@shilman.net

Afternoon coffee with @antfu.me is drinking from a firehose of web ecosystem knowledge and experience.

It’s been hours and my brain is still buzzing with ideas and excitement!

@antfu and @shilman selfie with thumbs up at Huashan 1914 Creative Park Taipei

December 26, 2024 at 9:54 AM

Michael Shilman

@shilman.net

Merry Christmas everybody! 🎄

My little girl manifesting holiday spirit in Narita airport. 😅

Four year old girl in pink Elsa princess dress screaming in crowded airport

December 25, 2024 at 9:29 PM

Michael Shilman

@shilman.net

Solved Advent of PBT 2024 day 1 with @fast-check.dev and @vitest.dev! 🎉

Property-based testing has been on my bucket list forever & it's so cool to learn it in the advent format. Inspiring!!!

Also learned there's a Zod adapter--gonna try that next. 🤓

import fc from 'fast-check';
import { test, assert } from 'vitest';
import sortLetters from './day-01.mjs';

const letter = fc.record({
name: fc.string({
minLength: 1,
unit: fc.constantFrom(...'abcdefghijklmnopqrstuvwxyz'),
}),
age: fc.integer({ min: 7, max: 77 }),
});

test('should sort letters by age and then alphabetically', () => {
fc.assert(
fc.property(fc.array(letter), (data) => {
const sorted = sortLetters(data);
for (let i = 1; i < sorted.length; ++i) {
const la = sorted[i - 1];
const lb = sorted[i];
assert(la.age <= lb.age);
if (la.age === lb.age) {
assert(la.name <= lb.name);
}
}
}),
{ numRuns: 1000 }
);
});

December 15, 2024 at 4:11 PM

Michael Shilman

@shilman.net

Minor accessibility PR to @storybook.js.org to fix heading structure across our documentation.

github.com/storybookjs/...

#basic-a11y #learninpublic

Skipping heading ranks can be confusing and should be avoided where possible: Make sure that a <h2> is not followed directly by an <h4>, for example. It is ok to skip ranks when closing subsections, for instance, a <h2> beginning a new section, can follow an <h4> as it closes the previous section.

https://www.w3.org/WAI/tutorials/page-structure/headings

December 1, 2024 at 3:47 AM

Michael Shilman

@shilman.net

Taking my little girl to see Moana 2 today — her first ever trip to the theater. Never imagined that I’d be this excited for a Disney movie! 😅 #dad

My daughter cheesing it up for the camera!

December 1, 2024 at 1:43 AM

Michael Shilman

@shilman.net

Deconstructing @bsky.app's UI in @storybook.js.org 🤓

Pairing on the new React Native Web framework with @dannyhw.com (⚡️ by @vite.dev). Good times!!!

November 30, 2024 at 5:21 PM

Michael Shilman

@shilman.net

Frontend testing is faster with @storybook.js.org. We slashed CI runtime for one of our early adopters by almost 50%!! 🤩

storybook.js.org/sb-test-eap