I use webpack path aliases for ES6 module loading.
E.g. If I define an alias for utils instead of something like
import Foo from \".
You can define custom paths, so WebStorm/PhpStorm can understand your aliases. But make sure, they are identical with your aliases. Create file in your root directory and call it something like this: webStorm.config.js (any js file will be ok). Then configure your paths inside:
System.config({
"paths": {
"components/*": "./src/components/*",
"core/*": "./src/core/*",
...
}
});
WebStorm/PhpStorm will recognize System as it's own module and will treat this file as configuration.