rollup

Bundle JavaScript modules for distribution

TLDR

Bundle JavaScript

$ rollup [main.js] --file [bundle.js]

Use configuration file

$ rollup -c

Output format

$ rollup [main.js] -o [bundle.js] -f [es]

Watch for changes

$ rollup -c --watch

Generate sourcemap

$ rollup [main.js] -o [bundle.js] -m

Bundle with a specific plugin

$ rollup [main.js] -o [bundle.js] -p [node-resolve]

rollup is a JavaScript module bundler focused on ES modules. It compiles small pieces of code into larger bundles, with excellent tree-shaking to eliminate unused code.The tool produces efficient bundles for libraries and applications, supporting multiple output formats.

PARAMETERS

-c file, --config file

Configuration file.

-o file, --file file

Output file.

-f fmt, --format fmt

Output format (es, cjs, umd, iife, amd, system).

-n name, --name name

UMD/IIFE global name.

-m, --sourcemap

Generate sourcemap.

-w, --watch

Watch mode.

-p plugin, --plugin plugin

Use plugin.

-d dir, --dir dir

Output directory (for code splitting).

-e modules, --external modules

Comma-separated list of external module IDs.

-g pairs, --globals pairs

Comma-separated global:module pairs for UMD/IIFE.

--no-treeshake

Disable tree shaking.

CONFIGURATION

rollup.config.js / rollup.config.mjs

Project-level configuration file defining input entry points, output formats, plugins, and external dependencies. Loaded automatically with -c or by specifying a path.

CAVEATS

Configuration needed for complex projects. Plugin ecosystem essential. CommonJS needs plugin. Build time can be slow for large projects.

HISTORY

Rollup was created by Rich Harris in 2015. It pioneered ES module bundling with tree-shaking, influencing later bundlers. Harris also created Svelte.