deno VS import-maps

NodeJS is the dominant Javascript server runtime environment for Javascript and Typescript (sort of) projects. But over the years, we have seen several attempts to build alternative runtime environments such as Deno and Bun, today’s subject, among others.

https://github.com/denoland/deno/issues is the ideal place -- we try to triage all incoming issues, the more specific the repro the easier it is to address but we will take a look at everything that comes in.

Install Node.js (or Bun, or Deno, or whatever JS runtime you prefer) if it's not there

QUIC is very exciting, after seeing what it can do for performance in Cloudflare network and Cloudflare workers, I can't wait to finally see it in Deno[0] 1.41.

[0] https://github.com/denoland/deno/pull/21942#issuecomment-192...

So as an end user it's kind of like https://deno.com/ where you buy into a runtime + comes prepacked with DBs (k/v stores), scheduling, and deploy stuff?

> by storing Unison code in a database, keyed by the hash of that code, we gain a perfect incremental compilation cache which is shared among all developers of a project. This is an absolutely WILD feature, but it's fantastic and hard to go back once you've experienced it. I am basically never waiting around for my code to compile - once code has been parsed and typechecked once, by anyone, it's not touched again until it's changed.

Interesting. Whats it like upgrading and managing dependencies in that code? I'd assume it gets more complex when it's not just the Union system but 3rd party plugins (stuff interacting with the OS or other libs).

~90MB+ at this stage and do now allow compression without erroring out. Deploying ala Golang is not feasible at that level but could well be down the line if this dev branch is picked up again!

The exe output grew from from ~50MB to plus ~90MB from 2021 to 2024: https://github.com/denoland/deno/discussions/9811 which mean Deno is worse than Node.js's pkg solution by a decent margin.

Behind the scenes is a simple Sveltekit-powered server function to fetch a Spotify client token then find a user's recommendation playlist and its track information. A Deno edge function to performs this data fetch and renders server-side Svelte.

If your application is written in JavaScript, integrating it with JavaScript extensions is a no-brainer. However, Secutils.dev is entirely written in Rust. How would I even begin? Fortunately, I recently came across an excellent blog post series explaining how to implement your JavaScript runtime in a Rust application with Deno:

Long time huge fan of JS. I appreciate your calling out the multi-paradigm aspect; having these first class functions & prototype based inheritance has been so flexible.

TC39 has done a great job shaping the language over the years. New capabilities are usually well thought out & integrate well. Async await has been amazing.

The one major miss that makes me so sad and frustrated is modules; js has gotten better everywhere except it's near requirement for build tooling. Being able to throw some scripts on a page and go is still an unparalleled experience in the world, is so direct & tactile an experience. EcmaScript Modules was supposed to improve things, help get us back, but imports using url specifiers made the whole thing non-modular, was a miss. We're still tangled & torn. Import-maps has finally fixed but it's no where near as straightforward, and it still doesn't work in workers, which leaves us infuriatingly shirt of where the past was. https://github.com/WICG/import-maps/issues/2

makes sure your app is getting the download it expects. Adoption is probably pretty minimal though. https://developer.mozilla.org/en-US/docs/Web/Security/Subres...

I think the big thing making this unlikely though is that very few folks use cdns these days. We designed ESM as a module system for the language, but then took a good fraction of a decade to build import-maps, to let us actually use modules in a modular way. Good news, we can finally use modules modularly! https://caniuse.com/import-maps

Bad news? Oh import-maps only works for the simplest case. Doesn't work in webworkers/service workers. https://github.com/WICG/import-maps/issues/2

The point is that single page apps almost always are bundled together, as using CDNs hasn't even been technically possible.

Also, CDNs are kind of somewhat pointless, now that http caches are partitioned by origin (for security reasons). They might have better anycast infrastructure to get the content out faster, but without the caching there's no inherent advantage. The user will download the same jquery file again in each site they go to, no already having it cached anymore. Bah humbug!

https://github.com/WICG/import-maps/issues/2

Bare specifiers has been the tragedy of ESM. Nice module syntax... that is utterly u deoyable & which has had to have awful de-modularizing specifiers hard-coded into each file to make it work. Abominable sin to introduce "modules" to JS/es2015 then spend a decade dragging everyone along with no story for how to have modular modules.

Import-maps are like "here" to fix this on the web... finally... except they only are shipping to the happiest sunniest easiest case, with Web Workers being totally shit out of luck in spite of some very simple straightforward suggested paths forward. https://github.com/WICG/import-maps/issues/2

I think Deno is making pretty good tradeoffs along the way here. This looks like package.json at surface level, but there is a nightmare of complexity under the surface. Typescript, ESM, cjs all have various pressures they create & in Node it's just incredibly tight & tense dealing with packaging, where-as Deno's happy path of Typescript first does not slowly tatters one over time. It really has been super pleasant being free of the previous world, and having something much more web-platform centric, more intented, with less assembly & less building, and more doing the actual coding.

I really hope import-maps eventually get broader support. Maybe this long-dwelling webworker issue should be brought up with WinterCG.

Import maps proposal

The concept of Import Maps was born in 2018 and made its long way until it was declared a new web standard implemented by Chrome in 2021 and some other browsers.

For package managers, you can use something like import maps to let the user specify which path points to what package, and resolve it properly.

Huh. I was about to complain that this breaks with web standards, but apparently it's being proposed as a standard feature: https://github.com/WICG/import-maps

Interesting!