default export should behave differently when it's the only export

[miloxeon]

When I don't use esmify and I write

module.exports = () => { ... }

and I build it like

browserify source.js -o dist.js -s "foo"

I can just write foo() and my function will be executed. However, when I use esmify and I write

export default () => {}

and build it the same way, foo actually represents an object that contains default property, so if I want to call it, I should write

foo.default()

I think that if there is a default export and there are no more exports, that exported value should be set to window.foo instead of an object.

[miloxeon]

I discovered a Rollup solution that does exactly what Browserify and Esmify can't and it does it much quicker.