A quick test to see how various bundlers compare when bundling the Lodash source code.

git clone [email protected]:Rich-Harris/bundler-comparison.git
git submodule update --init --recursive
npm i
npm run build

Note: Parcel gets a dramatically better outcome with the --experimental-scope-hoisting option (smaller than webpack, almost as small as Rollup). Parcel 2 enables this option automatically, but I couldn't get it to create a non-empty bundle.