rollup.config.js

import resolve from 'rollup-plugin-node-resolve'
import commonjs from 'rollup-plugin-commonjs'
import babel from 'rollup-plugin-babel'
import babelrc from 'babelrc-rollup'
import pkg from './package.json'

let external = Object.keys(pkg.dependencies)

export default [
  // browser-friendly UMD build
  {
    input: 'src/index.js',
    output: {
      file: pkg.main,
      name: 'd3',
      extend: true,
      format: 'umd',
      globals: {
        'd3-collection': 'd3',
        'd3-array': 'd3',
        'd3-interpolate': 'd3',
        'd3-path': 'd3',
        'd3-shape': 'd3'
      }
    },
    external,
    plugins: [
      resolve(), // so Rollup can find `d3`
      commonjs(), // so Rollup can convert `d3` to an ES module
      babel(babelrc())
    ]
  },

  // CommonJS (for Node) and ES module (for bundlers) build.
  // (We could have three entries in the configuration array
  // instead of two, but it's quicker to generate multiple
  // builds from a single configuration where possible, using
  // the `targets` option which can specify `dest` and `format`)
  {
    input: 'src/index.js',
    output: [
      {
        file: pkg.module,
        format: 'es',
        name: 'd3',
        extend: true,
        globals: {
          'd3-collection': 'd3',
          'd3-array': 'd3',
          'd3-interpolate': 'd3',
          'd3-path': 'd3',
          'd3-shape': 'd3'
        }
      }
    ],
    external,
    plugins: [babel(babelrc())]
  }
]