Question: Duplicate code elimination across npm modules

[zcei]

Question: Duplicate code elimination across npm modules

[Rich-Harris]

Great question! The thinking here us that for most UI widgets, the biggest dependency by far is the framework it's built against, meaning you never see people using (for example) React-based widgets unless their app is already using React (and that's before we start worrying about version mismatches etc).

The Svelte no-runtime approach doesn't mean that Svelte components have to bundle all their dependencies – the built components would be like any other JavaScript module, with possibly overlapping third party dependencies like lodash.uniq. (In many cases those dependencies are small enough that it does make sense to offer a self-contained UMD bundle, but that's a separate issue.) Most people would presumably have a build process that deduped third party dependencies in Svelte components like any others, so if you had this...

import ThisComponent from 'this-component';
import ThatComponent from 'that-component';

...and this-component and that-component both used lodash.uniq, you would only end up with one copy of it in your app.

[zcei]

Ah so I overestimated the power a bit.. it's not inlining dependencies except the svelte parts itself?
Just wondering whether there is a clear border between transformations, inlining, and further dependencies.

Very interesting approach, I'll try to follow along 🙂

[Rich-Harris]

Yep, if you want to inline the dependencies then you'll still use a module bundler for that (ahem) – the key difference with Svelte is that it doesn't add another dependency, unlike every other UI framework!