Cannot read property 'x' of undefined

[cmalven]

I've built a few sites using roadtrip, and there's an infrequent bug I've been noticing when navigating between routes:

Uncaught TypeError: Cannot read property 'x' of undefined

Here's the roadtrip code related to the error (though I imagine you can guess what it is):

_target = {
  href: location$1.href,
  scrollX: scroll.x, // <--- the source of the error
  scrollY: scroll.y,
  popstate: true, // so we know not to manipulate the history
  fulfil: noop,
  reject: noop
};

Steps to reproduce

• Open a page powered by roadtrip
• Navigate to any route
• Click the browser back button in the browser UI to return to the previous route
• Refresh the page using the browser UI
• Press the forward button in the browser UI to return to the previous route

I believe what is likely happening here is that refreshing the page clears road trip's scrollHistory, but roadtrip doesn't have a fallback for when a matching entry in the scroll history doesn't exist. Maybe?

[Kiho]

Hi @mrkishi,
Can you merge my PR and bump-up version in NPM?