esbuild Config Generator

esbuild is a JavaScript bundler and minifier written in Go. It's 10-100x faster than webpack or Rollup because Go compiles to native machine code (vs JavaScript interpreters), leverages Go's parallelism via goroutines, and uses efficient data structures throughout. Vite uses esbuild for dependency pre-bundling and TypeScript transpilation.

With bundle: true, esbuild recursively follows all import/require statements and combines everything into a single output file (or a few chunks). With bundle: false (the default), esbuild only transforms each file individually without following imports — useful for TypeScript-to-JS transpilation without bundling.

iife (Immediately Invoked Function Expression) wraps code in a function — ideal for browser <script> tags. cjs (CommonJS) uses module.exports — the standard for Node.js. esm (ECMAScript Modules) uses import/export — works natively in modern browsers and Node.js 12+. Choose based on your target environment.

External packages tell esbuild NOT to bundle those modules, leaving the import/require statement in the output. Use this for Node.js built-ins (fs, path, etc.) when targeting Node, or for peer dependencies like React that will be provided by the host environment, or for large libraries you load via CDN.

The target option tells esbuild which JavaScript syntax features to use in the output. 'es2015' transpiles modern syntax to ES5-compatible code for older browsers. 'esnext' outputs the most modern syntax with no downleveling. Targets can also be specific browsers like 'chrome90,firefox88' or Node versions like 'node16'.

Source maps are .map files that map minified/bundled code back to the original source. When you open DevTools with source maps, you see your original TypeScript/JSX files instead of minified output. Inline source maps embed the map in the output file (larger but simpler), external source maps create separate .map files.