rollup.config.js

import babel from 'rollup-plugin-babel'
import commonjs from 'rollup-plugin-commonjs'
import external from 'rollup-plugin-peer-deps-external'
import resolve from 'rollup-plugin-node-resolve'
import url from 'rollup-plugin-url'
import json from 'rollup-plugin-json'

import pkg from './package.json'

export default {
  input: 'src/index.js',
  output: [
    {
      file: pkg.main,
      format: 'cjs',
      sourcemap: true
    },
    {
      file: pkg.module,
      format: 'es',
      sourcemap: true
    },
    { file: 'dist/bundle.js', format: 'iife' }
  ],
  plugins: [
    external(),
    url({ exclude: ['**/*.svg'] }),
    babel({
      exclude: 'node_modules/**'
    }),
    resolve(),
    commonjs(),
    json({
      // All JSON files will be parsed by default,
      // but you can also specifically include/exclude files
      include: 'node_modules/**',
      exclude: ['node_modules/foo/**', 'node_modules/bar/**'],

      // for tree-shaking, properties will be declared as
      // variables, using either `var` or `const`
      preferConst: true, // Default: false

      // specify indentation for the generated default export —
      // defaults to '\t'
      indent: '  ',

      // ignores indent and generates the smallest code
      compact: true, // Default: false

      // generate a named export for every property of the JSON object
      namedExports: true // Default: true
    })
  ]
}