Hey, I had an issue on Chrome 56.x when I got:
Uncaught TypeError: $export is not a function console message on upon running the server first time.
My issue seems to be solved by finding this post on stack. And changing transform-runtime to following:
plugins: [
'add-module-exports',
'transform-decorators-legacy',
'transform-class-properties',
'transform-object-rest-spread',
['transform-runtime', {helpers: false, polyfill: false, regenerator: true}]
]