esbuild VS terser

Rollup is highly configurable via plugins. It also supports a wide range of transpilation targets. However, it's written in JavaScript (well, TypeScript) so there's a ceiling on how fast it can go. esbuild and swc are orders-of-magnitude faster than Rollup.

Note that `deno bundle` is deprecated. You can almost replace it with esbuild but it currently lacks builtin support for import maps:

    deno run --allow-all https://deno.land/x/[email protected]/mod.js --bundle app.js --outfile=bundle.js. # errors, see: https://github.com/evanw/esbuild/issues/2230

Want to import a package / file conveniently from esm.sh or unpkg or directly from a GitHub repo for a one-off script (for example). To do this I created a custom ESBuild plugin to handle HTTP imports - that worked for ,js files. To support running both ESM and CJS, I use tsx.

esbuild – is an easy-to-configure bundler,

As we iterate on the definition, we are going to want a better developer experience for rebuilding the package on changes. Typically, for a “library” or “utility” style package, I’d reach for either unbuild’s stub concept or use esbuild/tsup/rollup to implement a more traditional watch/rebuild, but in this case, I’m watching a proto file that lives outsides of the source, which breaks assumptions of those tools.

I use ESBuild (https://esbuild.github.io/) as a library for my almost pure Go toolchain, and it covers my requirements for almost 2 years now. ESBuild is the Go tool used in Vite, an incredible tool that I stopped using when I discovered that ESBuild covered all my needs.

As we can see, we have two external dependencies and one internal tool. In the modern way of packaging our application, we would be of course required to package this project using some bundler like ESBuild or Rollup. But with import maps, we can instead utilize CDN's to deliver our packages and completely eliminate the bundling step.

"Why?" you might ask. Vite is built on top of esbuild, a Go-based bundler for the web that is 10-100x faster than other bundlers such as webpack. Vite is also platform-agnostic, so you can learn the tool and use it for many applications.

Internally, esbuild is used. Esbuild has a plugin system, and I created custom plugins to resolve import statements like npm: and https://.

The other option I want to highlight is packaging the project using something like Webpack or esbuild. JS Bundlers transpile all of your separate files and classes (along with all node_modules) into one single file, a practice originally developed to reduce package size for frontend applications. This helps improve the cold start time in Lambda, as unimported files can be pruned and the entire handler becomes one file.

Terser is JavaScript compressor that can minified specific method names.

A minifier makes your code more compact so that it loads faster. Popular minifiers: Terser, swc.

There are many minifiers such as terser and uglify. But, because minifying also require to parse the JS, it is actually possible to use esbuild and SWC to minify the code. Here's a benchmark of the main minifiers.

This next one will help us reduce final bundle size by minifying the generated code. It's called rollup-plugin-terser and uses terser under the hood to minify the code.

fifty-three kilo-byte was a little bit large, and since the bundler i'm using for this package is rollup.js, all ineeded to do was install the terser — a JavaScript compressor toolkit for ES6 mdash; plugin for rollup.

You can see that the div function was copied “as is” and is not used in any way. When you run Webpack in production mode, it will remove this function. (Internally, Webpack relies on Terser for minification; Rollup performs tree-shaking and dead code elimination on its own.)

However, using the ESM packaging format has one advantage than CJS: tree-shaking. Tree-shaking is the concept of removing unused code from a dependency. Tools: esbuild, parcel, webpack, rollup, terser.

Install terser using yarn or npm.

Thus we have written our own module bundler by following the rollup way. We can also support a few extra options like code minification and mangling by using terser, we can also support iife format by wrapping the bundle with an iife expression. Since this is a basic example on how a bundler works, I have skimmed through a few stuffs, but in practice module bundlers are quite complex and interesting to learn about.

The project is built with itself, and uses some of the popular frontend libraries like codemirror and terser.To build a tilepieces application, read the instructions.