[Feature Request] Raise a specific error class for missing view

[ryanmccarthypdx]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe

A common pattern for using Blueprinter (at least at Procore) is to have the API consumers / clients request a specific blueprinter view via query params when making an http request. When the view they request does not exist, Blueprinter currently raises an error that looks like:

DEVELOPMENT(main)> WidgetBlueprint.render(Widget.last, view: :non_existent_view)
Blueprinter::BlueprinterError: View 'non_existent_view' is not defined

In this situation, we would want to raise a 400 and not a 500 for the end user. Blueprinter::BlueprinterError, however, is a very generic error and is used for things that could also be 500s.

Describe the feature you'd like to see implemented

I propose adding a new error class that inherits from Blueprinter::BlueprinterError for backwards compatibility purposes but which can be rescued separately and converted into 400s. Perhaps named Blueprinter::MissingViewError?

Describe alternatives you've considered

Currently, the workaround is to do something like this in the app:

      def blueprint_view
        return @blueprint_view if defined?(@blueprint_view)

        @blueprint_view = if DEFAULT_BLUEPRINT.view?(params[:serializer_view])
          params[:serializer_view]
        else
          self.class::DEFAULT_BLUEPRINT_VIEW
        end
      end

While #view? is a public method, I feel like the apps should not have to duplicate this effort that Blueprinter needs to do.

Additional context

No response

[jhollinger]

+1 from me. The V2 branch has an error for this already - maybe we just port that forward and add to V1? https://github.com/procore-oss/blueprinter/blob/e8fab6d369a353b8629b66d8161485fb3d2a0b35/lib/blueprinter/errors/unknown_view.rb