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v8.devJavaScript modules · V8This article explains how to use JavaScript modules, how to deploy them responsibly, and how the Chrome team is working to make modules even better in the future.

I don't think it matters for the web. But does for Node and the like: v8.dev/features/mod...

okay, so the docs I linked are outdated?

Barry Pollard

@tunetheweb.com

web.devCode-split JavaScript | web.devSome resources are not crucial to a web page's initial load. JavaScript is one such resource that can be deferred until the time of need through a technique known as code splitting. By doing so, y...

And yet oddly written after the doc I linked! @kevinfarrugia.bsky.social did you write web.dev/learn/perfor... ? Got any more info on mjs file extension?

I _think_ @kevinfarrugia.bsky.social thought the impact was minimal (but if it's even slight I think we should reconsider our default format in @nuxt.com and possibly also in @vite.dev). the key thing I'd like to confirm is that it really is the case first ...

github.com[blink] 2/2 Module streaming compilation for <link rel=preload> · chromium/chromium@3e261ebUse .mjs file extension to hint that a script should be streaming-compiled as module. Bug: 1178198 Change-Id: I3a99ef1131fbdb52cf439b488cd78485a955d8cf Reviewed-on: https://chromium-review.googles...

for example, this commit (if it's the _only_ optimisation) seems to suggest it might just apply to link preloads where `modulepreload` is not explicitly set: github.com/chromium/chr...

17/11/24, 3:48 pm0 reposts1 like

Noam Rosenthal

@nomster.bsky.social

Yea, that fix is about treating <link rel=preload href=foo.mjs> as if it's a modulepreload. I don't think Chromium has any mjs-specific things that cannot be achieved in better ways.

so this isn't correct? > Where V8 is concerned, you effectively opt out of streaming compilation when you ship JavaScript modules in production using the .js extension.

Noam Rosenthal

@nomster.bsky.social

I'm 95% sure that's incorrect for Chromium. The remaining 5% would require going through the code and finding nuggets like that preload one, and understanding their meaning.

Kevin Farrugia

@imkev.dev

"The core problem is that when starting streaming, we need to guess whether the script will be used as a module or not, since that will affect how the script is parsed. If we get that guess wrong, we just silently ignore the streaming parsing results and parse it again."

Kevin Farrugia

@imkev.dev