LG-5025: Create separate throttle error screen for proof_ssn throttle type

[aduth]

Why: So that each throttle error screen corresponds to exactly one throttle type, to accommodate accurate time labels proposed in #5301 (LG-4637).

[aduth]

Could make a query parameter for the failure route, I suppose? 🤔

[zachmargolis]

If we wanted to have one route and parameterize, I'd consider a path param:

      get '/session/errors/:error' => 'session_errors#show'

and then have #show do a 404 or something with an unknown params[:error]

[aduth]

If we wanted to have one route and parameterize, I'd consider a path param:

      get '/session/errors/:error' => 'session_errors#show'

and then have #show do a 404 or something with an unknown params[:error]

I explored this a bit, and I think there's room for refactoring here, though ultimately I struggled to find a reasonable improvement over just keeping the separate method here.

A few factors:

• There's several different warnings and errors for this controller, so it's unclear if we'd want a route segment for just the failures, or for every one of the possible screens. Maybe we could refactor this for one controller method which builds a presenter object for the specific throttle / messaging to be shown?
• We use a lot of URL helpers for these routes, which would need to be updated, e.g. idv_session_errors_failure_url to idv_session_errors_url(:failure). Not difficult, but widespread.
• Maybe at some point we'd want to have specific texts for the SSN proofing failure, at which point we'd not need to reuse the failure template like we are here, and can follow the established pattern.
• Considering LG-4637: Show accurate time remaining for IAL2 throttle screens #5301, we'll also need to set an instance variable for the appropriate throttle type, else we could just point directly to the controller method i.e. get '/session/errors/ssn_failure' => 'session_errors#failure'

[zachmargolis]

bummer, thanks for checking!

[zachmargolis]

If we wanted to have one route and parameterize, I'd consider a path param:

      get '/session/errors/:error' => 'session_errors#show'

and then have #show do a 404 or something with an unknown params[:error]

[zachmargolis]

LGTM