[added] router.replaceRoutes(children)

[gaearon]

Supersedes #606, that's the only missing piece. Let me know if you want tests for this; I'm not sure where to put them because there are not tests for addRoutes either. But this has been working for me for a few weeks so I don't think it's problematic.

[gaearon]

Don't know what's failing Travis but locally tests run fine.

[gaearon]

Note: I slightly tweaked this PR to include force parameter in dispatch.
This is necessary to force dispatch in case replaceRoutes affected current route.

[gaearon]

This still doesn't quite work as desired.

We talked with @mjackson about this and maybe it's worth extracting either some parts of dispatch or run into some kind of refresh method.

The scenario I need to support is following:

1. User goes to /a, A matches
2. I call replaceRoutes with new route config where /a maps to B
3. Router should be smart enough to figure out route config changed and dispatch a change

Right now, dispatch exits early with prevPath === path.

In this PR, I tried to fix this with force parameter, but it will only kick off dispatch if I call stop() and then run() after replacing routes. This is not correct either because we want to dispatch immediately after replaceRoutes.

[gaearon]

Changed the code to add refresh() method that works correctly regardless of whether the router is running or not. I removed callback argument from dispatch because it was always the same dispatchHandler. I already needed to move dispatchHandler outside run to implement refresh. Now that dispatchHandler was at the top, passing it as the last argument in each dispatch call seemed redundant. This also removes some of the perceived cognitive load IMO (dispatch always called the same callback but it wasn't apparent until you looked closely at the source).

[yaru22]

+1. This seems to be what I'm looking for. Can't wait to try it out.

[gaearon]

Rebased on top of current master. Can we please get this in?

[mjackson]

@gaearon This looks great. Thank you :)

[gaearon]

YEAAH