This is a demonstration of building a custom D3 v4 bundle using ES2015 modules and Rollup, following the example from https://gist.github.com/mbostock/bb09af4c39c79cffcde4.
This example exposes many field from the "regular" d3 object (but not all) and take into account some plugins (d3-selection-multi and d3-geo-projection).
To build:
npm install
npm run prepublish