middleware.js is not loaded by webpack and thus not transpiled by babel

[ndelangen]

I just attempted to load a middleware.js.

From the commit it would appear to be meant to support ES6 modules, but it doesn't.

This is my middleware.js:

const routes = (req, res, next) => {
  console.log('Hello world!');
  next();
};

export { routes as default };

When I run storybook this is the error I get:

> start-storybook -p 9009 -s public

@kadira/storybook v2.34.0

=> Loading static files from: /Users/dev/Projects/Playground/styled-components/public .
=> Loading custom addons config.
=> Loading custom webpack config.
/Users/dev/Projects/Playground/styled-components/.storybook/middleware.js:6
export { routes as default };
^^^^^^
SyntaxError: Unexpected token export
    at Object.exports.runInThisContext (vm.js:76:16)
    at Module._compile (module.js:542:28)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)
    at Module.require (module.js:497:17)
    at require (internal/module.js:20:19)
    at getMiddleware (/Users/dev/Projects/Playground/styled-components/node_modules/@kadira/storybook/dist/server/utils.js:53:28)
    at exports.default (/Users/dev/Projects/Playground/styled-components/node_modules/@kadira/storybook/dist/server/middleware.js:11:47)

[arunoda]

For now, you need to use ES5 and whatever the features supported by your node environment.
It's not going through webpack and we don't have plans either to do something similar.

Anyway, it's better if we document that.

[ndelangen]

Ok, I understand, it's just that addons.js actually is transpiled and so is config.js. So I was expeciting all files in the config folder to be transpiled.

Would you be interested in a PR that would allow ES6 in middleware.js?
Thanks.