unobtrusive and "as fast as it can be" polyfill for both Map and WeakMap methods such as getOrInsert and getOrInsertComputed: github.com/ungap/map-ex... Fully typed too 👋

if you have any interest in a possible future where JSON can serialize and deserialize more than just 5 types, follow this space/proposal 👋 es.discourse.group/t/jsonregist...

CORS landed in ds4 so it's now very simple to chat with it through this little (and fun) project from any mobile or desktop machine with a browser: github.com/WebReflectio...

my work and AI are not different topics anymore, here my TL;DR summary for May (busy times, I might not update that space as frequently as I've previously done) 👋 webreflection.github.io/standup/2026...

getOrInsertComputed in Map/WeakMap is actually pretty cool, it simplifies caching a lot and it's not limited to synchronous values, example: const cache = new Map; const asText = async page => fetch(page).then(r => r.text()); await cache.getOrInsertComputed('index', asText);

tired of the forward and backward tone/engagement around MutationObserver being able to snitch into Shadow DOM Roots? github.com/WebReflectio...

D1 is awesome but its API a bit "outdated" to me ... so I've written and tested template literals tags for it and I am pretty pleased with the result (and ergonomics). github.com/WebReflectio...

am I the only one seeing a repeatable pattern out of this story? AI is awesome if you know what to ask and what to build, it still requires knowledge around that "what", right? undark.org/2026/04/01/s...

updated to GNOME 50 and emoji-copy isn't working anymore? there you go: github.com/FelipeFTN/Em...

whenever I read posts like "don't us JS Array reduce" I'm like: const gcd = (a, b) => (b ? gcd(b, a % b) : a); const lcm = (a, b) => (a * b) / gcd(a, b); [2, 3, 4, 5].reduce((p, c) => lcm(p, c)); // 60 [12, 18, 36].reduce((p, c) => gcd(p, c)); // 6 I mean ... 🤷

apparently my account has been compromised on bsky ... it's honestly the only service out there that never offered me (until today), or enforced, 2FA, it was kinda inevitable, yet my deepest apologies if my account spam/scammed you by any mean 🙏

in case anyone is interested, I am documenting what I am working on regularly (each week) with links and every other detail needed to understand where I come from and where I am heading. This is OSS to me, nobody can blame me for not being transparent 😇 github.com/WebReflectio...

in today "nobody asked for it, thanks!" news, the recent issue filed against flatted module (333M downloads per months) kinda "scared" me to the point I rewrote the whole thing in a binary friendly format: flatted-view: please test it, thank you 🙏 github.com/WebReflectio...

flatted is out with a tiny yet important update for the JS variant: if you stringify 50K objects that point to each other you no longer have call stack recursion error on parse, it just works 🥳

in today "good morning OSS" news, @golang receives its first *flatted* implementation, making flatted now usable in JS, TS, Python, PHP and, ultimately Go 🥳 Huge thank to Harald Fielker for helping out (writing everything), lets' go beyond 300M Downloads! github.com/WebReflectio...

dear followers, I need to ask you a little favor: I am trying to fix the Web around SharedArrayBuffer and the ability to synchronize any task from a never blocking Worker, I need you to tell me if this page is blank or shows "async" as channel, thank you! webreflection.pythonanywhere.com

there's one primitive missing on the Web and that's the ability to synchronously make a Worker busy while querying the main thread ... in coincident I've solved that but the missing primitive is hurting a lot (for debugging reasons) so ... here I am again: github.com/WebReflectio...

today I’ve quickly glued together two libraries that makes custom elements without shadow dom as fast and as simple as it can get and for every browsers … after reading the N post about ShadowDOM issues with CSS. You can stop that madness already 👋 github.com/WebReflectio...

JS Proxy are wonderful, penalized by TS inability to actually understand/deal with these but the things that these unlock are incredible! It might be a niche use case but if you need cached results, here my next go-to library: github.com/WebReflectio...

this might be handy for any "forever waiting" pattern that requires instant reactivity + it doesn't leak compared to the original post that inspired it 😇 github.com/WebReflectio...

a common complain about our minimalistic TOML parser is that it wouldn't support trailing commas ... well, v0.4.0 does now, keeping it ~540bytes after brotli 🥳 github.com/WebReflectio...

"Let's Call The Whole Thing Off" 🎶🎵 github.com/WebReflectio...

if you use Proxies and you bind methods returned on `get` trap, please read carefully why that's a bad idea and how to avoid doing that: es.discourse.group/t/reflect-se...

so ... TOON is basically JSONH but 14 years later? ... cool 🙄 medium.com/medialesson/... github.com/WebReflectio...

I guess the idea that a customer might be away from home isn't intuitive to A FUCKING AIRLINE

Great, so www.britishairways.com 🎉 Displays in geo language rather than user language 🎉 The language picker is at the bottom of a long page 🎉 The language picker is in the current language, so in order to select "United Kingdom", I need to know what that is in German

cleaning up signals effects automatically on vanilla DOM cases might be tricky ... the fact an inner node contains references to its parent makes it hard to do so via FinalizationRegistry but thanks to Proxy/WeakRef it's possible to make it easy: weaky 🥳 github.com/WebReflectio...

brainstorming uhtml v5 and if you have hints/ideas/comments you are more than welcome to chime in 🙏 github.com/WebReflectio...

a quick introduction to regurlator 😇 www.youtube.com/watch?v=BJKm...

regurlator is out 🥳 chromewebstore.google.com/detail/regur...

tired of looking for "Open in Browser" links ??? I did create WebJeans and Woom (local only) but the pattern is always the same so I've put an end to this pointless struggle and published regurlator extension: you are in charge, you can redirect anything! github.com/WebReflectio...

this bug is the reason I am trying to provide a basic utility that would take care of everything out of the box as the dance to persist users' choice on local FileSystem access is nearly unbearable and convoluted in branches and operations to do ... 🥲 issues.chromium.org/issues/45453...

watch out developer.mozilla.org/en-US/docs/W... returns true while live-debugging because typing in devtools automatically activate transient mode. This might be a huge source of confusion and WYSI-NOT-WYG 👋

TIL: if you store in IndexedDB a granted FileSystemX handler you should als store with it options because if you close and reopen the browser, or create a new session, that handler will not work unless you check again against its permissions. Only then it prompts: once or always?

Davie504 is suing Suno AI and for very valid and good reasons: www.youtube.com/watch?v=RNHx...

TIL: event.intercept(...) after navigation.addEventListener('navigate', ...) 🤯 developer.mozilla.org/en-US/docs/W...

best honest video I've seen around Linux as developer: www.youtube.com/watch?v=GQJZ...

in which I've found a way to have "protected" properties only the class owner can handle. these can also be orchestrated as accessor: static a(self, ..._) { if (_.length) [self.#a] = _; return self.#a; }

Web extensions can query tabs and each tab can have a unique identifier that persist across refreshes but it's unique per tab (just like sessionStorage) if you need similar unique identifier on the server (uid per tab persistent on refreshes) here a demo: webreflection.github.io/session/

I need to ask this: how is it possible that `sessionStorage` cannot be replicated, as unique tab identity, on the server? My exploration tells me is entirely a browsers’ fault and nothing else … who has a reliable solution out there? (Nobody to my understanding) 🤦

A Service Worker nightmare used as fallback to sync blocking POST messages to circumvent the absence of SharedArrayBuffer, it needs hacks to resurrect such SW on occasions (open/close devtools, as example). On iOS / iPadOS devices that SW dies and there's nothing one can do 🤦

TIL ... WebNN (Neural Network) API ... I feel like this is needed "yesterday" already, hope to see it implemented soon in all relevant browsers www.w3.org/TR/webnn/

I've lost the count of times I've written: el.append( Object.assign( document.createElement('div'), { textContent: '...', className: '...', onclick: ... } ) ) so I've written a minimalistic helper that does just that and very little more 😇 github.com/WebReflectio...

mixed feelings around JS prototype pollution ability: it has been playing really well for polyfills to date but it allows any malicious code to observe/intercept everything the env does, especially `await` operations via Promise.prototype.then pollution Any other PL like that? 🤔

is this a @TauriApps alternative that actually just needs node/bun ffi and for some reason I had no idea about it? 🤔 github.com/saucer/saucer

highly inspired by Geist UI File-Tree a made a <file-tree /> custom element that should "just work" with minimal size and zero tooling needed! demo: webreflection.github.io/file-tree/te... project: github.com/WebReflectio...

in other news, uhtml v5 is ready: * it's nearly as fast as v4 for keyed results except it doesn't need specialized URLs or buils: <el key=${k} /> it is * it's faster in non-keyed scenarios * it has components backed into core * components have (alien) signals reactivity * it's 5K

iframe.src = `data:text/html;charset=utf-8,${yourStuff}` is *NOT* the way to go as it loses all privileges granted from the page creating such iframe. const blob = new Blob([yourStuff], {type: 'text/html'}); iframe.src = URL.createObjectURL(blob); though works like a charm 😇

another day in "Proxy land", about the time to publish this: webreflection.medium.com/taming-js-pr...

TIL: import.meta.resolve('./relative/path') Goodbye: new URL('./relative/path', import.meta.url).href 🥳 developer.mozilla.org/en-US/docs/W...