[v6] default route redirects

[bokelley]

Hi there. We are trying to upgrade our product to v6, and are running into an issue with default routes. We have a component TradeScreen that displays trades for a certain date, and use the path /trades/:yyyy/:mm/ to get there. We also want the path /trades/ to route to the current year and month.

The naive approach to this was something like this:

<Routes>
  <Route path="/" element={<Navigate to={"/trades/" + year + "/" + month}/>}/>
</Routes>

This sort of works, but because <Navigate> uses an effect, it actually renders the page, then does the redirect.

I understand why this needs to be an effect, but I wonder if it would make sense to have a callback that we could use, like translatePath() where we could say "please route /trades as if it were /trades/2020/07". Or maybe there is just a routing table that we pass in with the original <Router>. That keeps the underlying component independent of this routing logic but doesn't force a client-side redirect.

Open to other approaches to this, but feels like we need something here. (Also, before you say "why don't you just make the default year/month in your component if nothing is passed... sure... but how about a simple case where I want to route / to /trades when the user logs in?)

[timdorr]

Please see the discussion in #7267.