Suggestion: Throw error if user calls UIRouterReact.start() twice

[telekid]

I burned a few hours attempting to fix an issue that was actually a side-effect of unintentionally calling start() on my router object twice – once in my router.config file (inspired by the sample app,) and then once again by passing router to the UIRouter component.

The trouble is, it isn't particularly obvious that passing a UIRouterReact class to a UIRouter component (<UIRouter router={router}></UIRouter>) automatically calls the start() method on router.

Since I can't actually think of any reason why a user would choose to call router.start() twice in the same application, it may be prudent to throw an error if a user attempts to do so.

[elboman]

Yeah, we should definitely warn the user if the start method is called more than once.

The thing is, since the UIRouter component takes care of start()ing the router whether you pass it an instance or let it create the instance for you, I don't think you ever need to do it yourself.

We should definitely update the sample app (as it's using the old version/syntax) as well as migration guide from the 0.4.x

Thanks for the heads up!