rollup.config.js
// rollup.config.js
import resolve from 'rollup-plugin-node-resolve';
import babel from 'rollup-plugin-babel';
import uglify from 'rollup-plugin-uglify';
import sourcemaps from 'rollup-plugin-sourcemaps';
export default {
entry: 'es6/index.js',
format: 'cjs',
sourceMap: 'inline',
external: ['node-fetch'],
plugins: [
resolve({jsnext: true}),
sourcemaps(),
babel({
exclude: 'node_modules/**' // only transpile our source code
}),
uglify()
],
dest: 'es5/index.js'
};