index.js

import path from 'path';

console.log(Object.keys(path));

rollup.config.js

import includePaths from 'rollup-plugin-includepaths';
import builtins from 'rollup-plugin-node-builtins';

let includePathOptions = {
    include: {},
    paths: ['src'],
    external: [],
    extensions: ['.js', '.json', '.html']
};

export default {
    entry: 'index.js',
    format: 'cjs',
    dest: 'app.js',
    plugins: [
        builtins(),
        includePaths(includePathOptions)
    ],
};