A masochist's guide to web development

https://sebastiano.tronto.net/blog/2025-06-06-webdev/

by sebtron • 1 year ago

285 52 1 year ago

sebastiano.tronto.net

udev4096• 1 year ago

What's with the use of port 48 for SSL? Any particular reason?

sebtron• 1 year ago

Ah, that's a good question. It's kinda random (except that the name of the solver is "H48"). Setting up that web app required some extra HTTP headers (I explain that in the post), and the easiest way I found to do that without messing up the rest of my website was using a different port. https://h48.tronto.net redirects there too.

Later I looked into a better way to do this, but I could not fully work it out. I use OpenBSD's httpd, which does not support setting extra headers, and relayd. At some point I'll take a look at this again, or I'll move the tool to another domain.

wmichelin• 1 year ago

`var myLibraryInstance = away MyLibrary();`

lerax• 1 year ago

Masochist? that's much more sane than the js clusterfuck ecosystem

rapind• 1 year ago

"Clusterfuck" is implicit and may be omitted.

broken_broken_• 1 year ago

Good article, I also have a C program (a compiler) that I would like to compile to webassembly to offer a playground web page, so that is good information. Thank you!

About the file system stuff: modern browsers ship with SQLite which is available to JavaScript (is it available to webassembly? No idea) so I would probably use that instead. Ideally you could use the sqlite API directly in C and emscripten would bridge the calls to the browser SQLite db. Something to investigate.

lscharen• 1 year ago

Notice I have changed the extension from .js to .mjs. Don’t worry, either extension can be used. And you are going to run into issues with either choice

As someone that has used module systems from dojo to CommonsJS to AMD to ESM with webpack and esbuild and rollup and a few others thrown in ... this statement hits hard.

bubblyworld• 1 year ago

Yeah, modules in jsland are just trauma... now we have import maps in the browser too. Let's see what kinds of fun we can have with those.

ajayvk• 1 year ago

A recent improvement in import map support in the browser https://shopify.engineering/resilient-import-maps

SCLeo• 1 year ago

Yeah, the commonjs to esm transition has been the python 2 to python 3 transition of JavaScript, except the benefits are limited (at least compared to the hassle created).

There are many libraries that have switched to esm only (meaning they don't support commonjs), but even today, the best way to find the last commonjs version of those libraries is to go to the "versions" tab on npm, and find the most downloaded version in the last month, and chances are, that will be the last commonjs version.

Yes, in a vacuum, esm is objectively a better than commonjs, but how tc39 almost intentionally made it incompatible with commonjs (via top-level awaits) is just bizarre to me.

eyelidlessness• 1 year ago

It had to be incompatible with CommonJS regardless of top level await. There is no imaginable scenario where browsers would ship a module system with synchronous request and resolution semantics. A module graph can be arbitrarily deep, meaning that synchronous modules would block page load for arbitrarily deep network waterfalls. That’s a complete non-starter.

Given that, top-level await is a sensible affordance, which you’d have to go out of your way to block because async modules already have the same semantics.

Recently, Node has compromised by allowing ESM to be loaded synchronously absent TLA, but that’s only feasible because Node is loading those models from the file system, rather than any network-accessible location (and because it already has those semantics for CJS). That compromise makes sense locally, too. But it still doesn’t make sense in a browser.

apatheticonion5• 1 year ago

Bundler engineer here. ESM is great when it comes to build-time optimisations. When a bundler runs into CJS code it literally deopts the output to accommodate - so from that side it's amazing.

But also, there's a special place in hell for the people that decided to add default exports, "export * from" and top level await.

Commonjs is also very weird as a "module" instance can be reassigned to a reference of another module

module.exports = require('./foo')

and there's no way to do this in ESM (for good reason, but also no one warned us). In fact major projects like React use CJS exports and the entire project cannot be optimized by bundlers. So, rather than porting to ESM, they created a compiler LOL

zackify2• 1 year ago

That’s why everyone should be using bun.sh

VWWHFSfQ• 1 year ago

Web dev is full of "you should just use some other tool that I like"

I'm convinced that 90% of the JavaScript ecosystem only exists to build tools for itself. It's tools all the way down

BostonFern• 1 year ago

Won’t .esm.js work?

goodthink• 1 year ago

I recently found out that the Function object will compile any javascript you care to feed to it. At runtime! new Function('class MyClass { ...}; return MyClass') My system does not allow for "imports". No npm etc. So this is a bit of a lifesaver for me. I realize in js land it may not be as useful but it is pretty handy.

divbzero• 1 year ago

I always assumed that compiling code to run in the browser would be slow, but OP points out that this is not the case. As the Emscripten project describes:

Thanks to the combination of LLVM, Emscripten, Binaryen, and WebAssembly, the output is compact and runs at near-native speed.

https://emscripten.org/

RobRivera• 1 year ago

Yellow bus syndrom in action for me today.

Last week I never heard of Emscripten.

Integrating SDL for a project, there were CMake callouta for APPLE, MSVC, and EMSCRIPTEN.

And here we are seeing it again on hn in a few days.

I should put an afternoon aside for some deep diving on it for context.

scubbo2• 1 year ago

Yellow bus syndrome in action for me today

There's a certain irony to being able to introduce you to the term "Baader-Meinhof Phenomenon" (which is the more-common name for what I assume you're referring to, as Google searches for "Yellow Bus Syndrome" didn't bring anything up for me). Now you know the name, you'll see it everywhere!

burningChrome• 1 year ago

> the output is compact and runs at near-native speed.

This kind of subjective, no? I wonder what they consider "near native speed"? I couldn't find any real numbers in their documentation.

gspencley• 1 year ago

Not only is it subjective but V8 does so much to optimize JavaScript code that I wouldn't be surprised if the benefits for most applications were negligible anyway.

Although JavaScript is still an interpreted language, it basically gets "compiled" when the browser parses the bundle. On the surface, the only thing WebAssembly automatically gets you is you get to skip the runtime compilation phase.

I might be talking out of my ass, so take this with a grain of salt, but I wouldn't be surprised if once we start collecting real data on this stuff, SOME WebAssembly code could actually run slower than just using JS code. My hypothesis is that if you're starting with non-JavaScript code, you might be doing things in that language that would be slower to do the same way in JavaScript. I'm thinking of things like Array.map(), .filter() etc. ... which are hyper-optimized in V8. If you're taking an algorithm from C code or something which then gets compiled to WebAssembly, it's not an automatic given that it's going to compile to WebAssembly that is just as optimized as what V8 would do when it comes across those API calls. Again, this is just a hypothesis and I could be way off base.

In any case, what we need is real world data. I have no doubt that for certain applications you can probably avoid land mines by hiring devs who are experienced building certain performance-critical things at a lower-level than your average JS dev... and their experience in those languages may transfer very well to the browser. In this scenario, you're not getting huge perf wins from using WebAssembly per-se... you're getting huge perf wins for not doing typical stupid, lazy, ignorant things that most average JS devs do ... like cloning large objects using the spread operator and then doing that over and over and over again "because immutability."

knallfrosch2• 1 year ago

Nice writeup! You definitely chose a pretty hard way, but the project setup is always the most complex part. Bonus points for immediately running into security/header issues, but my bet would have been CORS.

At $WORK, we're also building with emscripten/C++. We'll add WebGPU/shaders and WebAudio for bonus pain.

socalgal2• 1 year ago

There is more here that is likely to cause problems in the future. One is the author's use of var instead of let or const. var continues to work but most JS devs have linters that ban the use of var. The issue is, var has function scope, not brace scope. Most non-JS devs coming from other languages will eventually run into this issue.

Another issue porting native apps is, native apps are compiled for a specific platform and hardcoded to that platform's conventions. A good example of this is hardcoding Ctrl-C (copy), Ctrl-V (paste) at compile time, which maybe works on Linux and Windows but doesn't work on Mac.

IIRC the way you're supposed to handle this on the web is listen for copy and paste events. AFAIK Unity has this issue. They hard coded Ctrl-C, Ctrl-P and so copy and paste don't work on Mac. Most games don't need copy and paste but once in a while someone does something that does need it, then exports to the web and runs into this issue.

maximevince• 1 year ago

Thanks for this wonderful writeup!

apatheticonion5• 1 year ago

God I hate multi-threading on the web/nodejs. Rather than implementing syncronization primatives like mutexes or rwlocks that capture the contained values and make them "transferrable" between JavaScript contexts (v8 isolates) - they introduced SharedArrayBuffer that is almost entirely unusable for anything meaningful.

Syncronizing between threads involves thunking and copying data through RPC layers.

Sucks for me because our production app has grown faster than we are able to rewrite it and uses 70-100gb of ram (written before my time). To try to get around this, we are investigating exotic solutions like using native code to manually manage pages of shared memory that contains custom data structures and as little serialization/deserializing logic as possible - but of course v8 uses utf16 for string encoding which means working with JavaScript values in the native layer is expensive.

knallfrosch2• 1 year ago

100GB of RAM — I'm curious, why is this a web app? Sounds like an internal tool that could have been written in, for example, C#.

jiggawatts2• 1 year ago

Microsoft doesn’t exist in the hive mind of Silicon Valley. That’s the only reason.

“We’d rather spend 3x the effort to bash things with open source rocks than ever use a proprietary hammer!”

“.NET is open source. It also comes with a steam roller.”

“We’ve made up our minds!”

PS: I just had to work on a Node.js app for the first time in my career. After dotnet core it feels like working with children’s wood blocks.

apatheticonion5• 1 year ago

It's actually an internal build tool (forked from an open source tool) used to build our public applications and runs in Nodejs. We are rewriting it in Rust but it's a complex tool and that takes a lot of time.

In the mean time, a "build" using this Nodejs based tool takes about an hour and uses 100gb of RAM.

By contrast, preliminary unoptimized results of the Rust tool brings build times down from 1 hour to 1 minute and maxes out at 6gb of ram - but that'll be finished in 2 years.

It literally costs millions per year to run and is a nightmare to maintain.

To be fair, the JavaScript itself is actually surprisingly performant - it's the multi-threading that's the real problem.

It would be a non issue if there were memory sync primitives that could be sent between threads but because of how v8 isolates work, this isn't possible without changes to v8. So we are forced to copy gigantic graphs of data between threads and manually synchronize them with postMessages.

Running a build on the main JS thread (no workers) uses 10gb of ram and takes 5 hours. So shared memory would solve our issue and avoid the need to rewrite it.

Attempts to centralize the data (in a DB or similar) perform worse due to the de/serialization of the data. Other attempts of using a shared in-memory database shares the same issue. We also need to modify every shared structure in the codebase to use getters/setters with a copy on read approach (so memory blows up any way).

It's not that JavaScript itself is the wrong language, but that the isolated nature of the runtimes fail in multi-threaded use cases.

A masochist's guide to web development

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