Removing the catch all route.

[T4rk1n]

There is a catch all route in dash, it catch any route that doesn't exist and return a 200 with the index. I think this is bad and should be removed as it swallow errors.

dash/dash/dash.py

Lines 214 to 217 in a6388be

	# catch-all for front-end routes
	add_url(
	'{}<path:path>'.format(self.config['routes_pathname_prefix']),
	self.index)

Example of unexpected behavior coming from this:
The browser tries to get the /favicon.ico from the server and dash replies OK here's the index. That means the browser will try to get the favicon everytime you load the index since it returns a 200 instead of a 404.

[T4rk1n]

cc @plotly/dash

[rmarren1]

Will this break multi-page apps that rely on the Location? (e.g. this)

I always thought this catch-all was to support this functionality, especially in the case where a user navigates directly to a page rather than manipulating the Location via a callback.

[T4rk1n]

I see, it's probably because of that, it's a good reason to keep it then.

[chriddyp]

Yeah, that's why we have it

[ned2]

I wonder if it might be nice to at least fix the special case of the /favicon.ico route (as discussed in #152). As it can be a little confusing to see the index being returned as the body of the favicon response.