If I import foundation as

import {} from './node_modules/foundation-sites/dist/foundation.js';

only last _createClass helper definition stays, others gets removed. Problem is that every definition of _createClass helper is in their own iffe scope, so I am getting 'undefined' on _createClass helpers calls.

If I import foundation plugins one by one as

import {} from './node_modules/foundation-sites/dist/plugins/foundation.core.js';
import {} from './node_modules/foundation-sites/dist/plugins/foundation.abide.js';
import {} from './node_modules/foundation-sites/dist/plugins/foundation.orbit.js';

it works as expected, _createClass helpers gets namespacing and they are not removed.

rollup 0.31.0, no plugins