esbuild

What is esbuild?

esbuild is a fast JavaScript bundler and minifier. It compiles TypeScript and JavaScript into a single file, minifies it, and can also handle CSS and image assets. It's designed for speed and efficiency, utilizing parallelism and native Go code to achieve its performance.

What are esbuild's main functionalities?

Bundling JavaScript

This code bundles 'app.js' and its dependencies into a single file 'out.js'.

require('esbuild').build({
  entryPoints: ['app.js'],
  bundle: true,
  outfile: 'out.js'
}).catch(() => process.exit(1))

Minifying JavaScript

This code minifies 'app.js' to reduce file size and improve load times.

require('esbuild').build({
  entryPoints: ['app.js'],
  minify: true,
  outfile: 'out.js'
}).catch(() => process.exit(1))

Transpiling TypeScript

This code compiles a TypeScript file 'app.ts' into JavaScript and bundles it into 'out.js'.

require('esbuild').build({
  entryPoints: ['app.ts'],
  bundle: true,
  outfile: 'out.js'
}).catch(() => process.exit(1))

Serving files for development

This code starts a local server to serve files from the 'public' directory and bundles 'app.js' into 'public/out.js'.

require('esbuild').serve({
  servedir: 'public',
  port: 8000
}, {
  entryPoints: ['app.js'],
  bundle: true,
  outfile: 'public/out.js'
}).then(server => {
  // Server started
})

Other packages similar to esbuild

webpack

Webpack is a powerful and widely-used module bundler. It offers a rich plugin ecosystem and a highly configurable build process. Compared to esbuild, webpack is more mature with more features but is generally slower due to its JavaScript-based architecture.

rollup

Rollup is another JavaScript module bundler that focuses on producing efficient bundles for modern module formats like ES modules. It's known for its tree-shaking capabilities. Rollup is typically faster than webpack but slower than esbuild.

parcel

Parcel is a web application bundler that offers zero configuration out-of-the-box. It's faster than webpack and rollup but generally not as fast as esbuild. Parcel has a simpler user experience but may not be as flexible for complex configurations.

terser

Terser is a JavaScript parser, mangler, and compressor toolkit for ES6+. It's often used for minifying JavaScript code. While esbuild also minifies code, terser is a dedicated tool for this purpose and can be used alongside other bundlers.

README

esbuild

This is a JavaScript bundler and minifier. See https://github.com/evanw/esbuild and the JavaScript API documentation for details.

Changelog

0.25.8

• Fix another TypeScript parsing edge case (#4248)

  This fixes a regression with a change in the previous release that tries to more accurately parse TypeScript arrow functions inside the ?: operator. The regression specifically involves parsing an arrow function containing a #private identifier inside the middle of a ?: ternary operator inside a class body. This was fixed by propagating private identifier state into the parser clone used to speculatively parse the arrow function body. Here is an example of some affected code:

  class CachedDict {
    #has = (a: string) => dict.has(a);
    has = window
      ? (word: string): boolean => this.#has(word)
      : this.#has;
  }
  

• Fix a regression with the parsing of source phase imports

  The change in the previous release to parse source phase imports failed to properly handle the following cases:

  import source from 'bar'
  import source from from 'bar'
  import source type foo from 'bar'
  

  Parsing for these cases should now be fixed. The first case was incorrectly treated as a syntax error because esbuild was expecting the second case. And the last case was previously allowed but is now forbidden. TypeScript hasn't added this feature yet so it remains to be seen whether the last case will be allowed, but it's safer to disallow it for now. At least Babel doesn't allow the last case when parsing TypeScript, and Babel was involved with the source phase import specification.