css-in-js VS Rollup

As you might have realized by now, the front end ecosystem is saturated with tools, and unsurprisingly, tools have been invented to partially solve some of the problems with writing CSS at scale. "At scale" means that many developers are working on the same large project and touching the same stylesheets. There is no community-agreed approach on writing CSS in JS at the moment, and we are hoping that one day a winner would emerge, just like Redux did, among all the Flux implementations. For now, we are banking on CSS Modules. CSS modules is an improvement over existing CSS that aims to fix the problem of global namespace in CSS; it enables you to write styles that are local by default and encapsulated to your component. This feature is achieved via tooling. With CSS modules, large teams can write modular and reusable CSS without fear of conflict or overriding other parts of the app. However, at the end of the day, CSS modules are still being compiled into normal globally-namespaced CSS that browsers recognize, and it is still important to learn and understand how raw CSS works.

There are a myriad of CSS-in-JS tools, many of which are zero-runtime giving you all the benefits of authoring in a single file without the drawbacks of inline styles. That's how I prefer to do my CSS with React anyway... Vanilla Extract and/or Linaria are my current favorites.

One thing I think you're really missing is what the output is of CSS-in-JS. There are tens of CSS-in-JS frameworks that can output anything from: CSS Module like classes (Linaria, Vanilla Extract), Atomic Classes (StyleX, PreStyle), to the more traditional (Styled Components, Emotion) many with zero runtime cost (ie no JS bloat). That's why I say CSS-in-JS is primarily about developer experience... the output can often be whatever you want it to be.

Doesn't Rollup already use quite a bit of rust[0]? It's actually why I had to abandon it for a project, where they didn't offer binaries for our build platform and I needed to bundle, like 2 ES6 javascript libraries so I just grabbed esbuild instead.

[0] https://github.com/rollup/rollup/tree/master/rust

Unlike Webpack, the Vite DevServer only compiles files when they are requested. It leverages ES module imports, which allow JS files to import other files without needing to bundle them together during development. When one file changes, only that file needs to be re-compiled, and the rest can remain unchanged. Project files are compiled with Rollup.js. Third-party dependencies in node_modules are pre-compiled using the ultra-fast esbuild bundler for maximum speed, and they are cached until the dependency version changes. Vite also provides a client script for hot module reloading.

Read the full breaking changes in Rollup’s release notes for build-related changes in build.rollupOptions.

Besides Webpack, there are many other popular web bundlers available, such as Parcel, Esbuild, Rollup, and more. They all have their own unique features and strengths, and you should make your decision based on the needs and requirements of your specific project. Please refer to their official websites for details.

The optimization points are very valid and good to keep in mind, no?

See for example:

https://github.com/rollup/rollup/issues/349

The missing minification of identifiers and properties of the Vue instance in general were always bugging me in Vue 2, even when not using the class keyword.

This is a very valid consideration IMO.

In the Node.js ecosystem, bundling is typically handled by third-party tools rather than Node.js itself. Some of the most popular bundlers in the Node.js world include Webpack, Rollup, and Parcel, offering features like code splitting, tree shaking, and hot module replacement.

📦 Rollup for bundling

Bundling: Webpack, Parcel, Rollup

Rollup is another popular JavaScript module bundler focusing on high performance. It excels at tree-shaking and uses ES module syntax to generate more performant bundles than traditional module bundlers. In addition to JavaScript, Rollup supports bundling CSS and JSON as well. Rollup has more than 12 million weekly NPM downloads.

Vite (read as vit) is actually a combination of two great frontend tools - an immensely fast development server and a build command for shipping heavily optimized static assets using Rollup. Many developers have encountered the process of setting up a project using Create React App. While CRA can be useful for beginners due to its simplicity and abstraction of configuration, it has some drawbacks that outweigh its benefits, particularly its tendency to be bloated. Don't get me wrong, Vite is opinionated as well, but it's highly extensible through its Plugin API.