I got syntax highlighting errors in PhhpStorm when using the EcmaScript6 (harmony version) module syntax.
When I use this code (to be sure its not a fault): https://github.com/stefanpenner/ember-app-kit-todos/blob/master/app/models/todo.js
Then I get the following errors in my editor:
I have enabled Ecmascript Harmony for the Javascript syntax highlighting in the settings.
Edit: see here a second example using an import call:
ES6 modules are still unsupported, vote for the issue on JetBrains bug tracker.
Support Harmony modules