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

0.23.1

• Allow using the node: import prefix with es* targets (#3821)

  The node: prefix on imports is an alternate way to import built-in node modules. For example, import fs from "fs" can also be written import fs from "node:fs". This only works with certain newer versions of node, so esbuild removes it when you target older versions of node such as with --target=node14 so that your code still works. With the way esbuild's platform-specific feature compatibility table works, this was added by saying that only newer versions of node support this feature. However, that means that a target such as --target=node18,es2022 removes the node: prefix because none of the es* targets are known to support this feature. This release adds the support for the node: flag to esbuild's internal compatibility table for es* to allow you to use compound targets like this:

  // Original code
  import fs from 'node:fs'
  fs.open
  
  // Old output (with --bundle --format=esm --platform=node --target=node18,es2022)
  import fs from "fs";
  fs.open;
  
  // New output (with --bundle --format=esm --platform=node --target=node18,es2022)
  import fs from "node:fs";
  fs.open;
  

• Fix a panic when using the CLI with invalid build flags if --analyze is present (#3834)

  Previously esbuild's CLI could crash if it was invoked with flags that aren't valid for a "build" API call and the --analyze flag is present. This was caused by esbuild's internals attempting to add a Go plugin (which is how --analyze is implemented) to a null build object. The panic has been fixed in this release.

• Fix incorrect location of certain error messages (#3845)

  This release fixes a regression that caused certain errors relating to variable declarations to be reported at an incorrect location. The regression was introduced in version 0.18.7 of esbuild.

• Print comments before case clauses in switch statements (#3838)

  With this release, esbuild will attempt to print comments that come before case clauses in switch statements. This is similar to what esbuild already does for comments inside of certain types of expressions. Note that these types of comments are not printed if minification is enabled (specifically whitespace minification).

• Fix a memory leak with pluginData (#3825)

  With this release, the build context's internal pluginData cache will now be cleared when starting a new build. This should fix a leak of memory from plugins that return pluginData objects from onResolve and/or onLoad callbacks.