rollup.config.js

import json from 'rollup-plugin-json';
import babel from 'rollup-plugin-babel';
import node from 'rollup-plugin-node-resolve';
import commonjs from 'rollup-plugin-commonjs';


export default {
    input: 'index.js',
    output: {
        format: 'umd',
        name: 'd3',
        file: 'build/d3-let.js',
        extend: true
    },
    plugins: [
        json(),
        node(),
        babel({
            babelrc: false,
            plugins: ['external-helpers'],
            presets: ['es2015-rollup'],
            externalHelpers: true
        }),
        commonjs({
            include: ['node_modules/**']
        })
    ]
};