Sort functionality not robust to missing order

[pgwillia]

A plagarism checking bot has discovered a bug with our sorting. Can reproduce by visiting http://era.lvh.me:3000/search?sort=sort_year in development.

jupiter/app/models/jupiter_core/solr_services/deferred_faceted_solr_query.rb

Lines 71 to 81 in 6fff30c

	criteria[:sort_order] << if sort_attribute == :score
	# When sorting by score it only makes sense to use :desc order from the user
	# perspective so we ignore the order if one is given.
	:desc
	elsif order.present? && POSSIBLE_SORT_ORDERS.include?(order)
	order
	else
	# We could not find the order so we switch to default sort direction
	sort_direction_index = solr_exporter.default_sort_indexes.index(sort_attribute)
	solr_exporter.default_sort_direction[sort_direction_index]
	end

Where

• sort_attribute is "sort_year_isi"
• order is nil
• solr_exporter.default_sort_indexes.index(sort_attribute) is nil

Then on line 81 the TypeError is thrown.

View details in Rollbar: https://rollbar.com/ualbertalib/jupiter/items/1192/

TypeError: no implicit conversion from nil to integer
  File "/var/www/sites/jupiter/app/models/jupiter_core/solr_services/deferred_faceted_solr_query.rb", line 80, in block in sort
  File "/var/www/sites/jupiter/app/models/jupiter_core/solr_services/deferred_faceted_solr_query.rb", line 49, in each
  File "/var/www/sites/jupiter/app/models/jupiter_core/solr_services/deferred_faceted_solr_query.rb", line 49, in each_with_index
  File "/var/www/sites/jupiter/app/models/jupiter_core/solr_services/deferred_faceted_solr_query.rb", line 49, in sort
  File "/var/www/sites/jupiter/app/services/user_search_service.rb", line 37, in results
  File "/var/www/sites/jupiter/app/controllers/search_controller.rb", line 24, in index
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_controller/metal/basic_implicit_render.rb", line 6, in send_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/abstract_controller/base.rb", line 195, in process_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_controller/metal/rendering.rb", line 30, in process_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/abstract_controller/callbacks.rb", line 42, in block in process_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/callbacks.rb", line 135, in run_callbacks
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/abstract_controller/callbacks.rb", line 41, in process_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_controller/metal/rescue.rb", line 22, in process_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_controller/metal/instrumentation.rb", line 33, in block in process_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/notifications.rb", line 180, in block in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/notifications/instrumenter.rb", line 24, in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/notifications.rb", line 180, in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_controller/metal/instrumentation.rb", line 32, in process_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_controller/metal/params_wrapper.rb", line 245, in process_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activerecord-6.0.3.4/lib/active_record/railties/controller_runtime.rb", line 27, in process_action
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/abstract_controller/base.rb", line 136, in process
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionview-6.0.3.4/lib/action_view/rendering.rb", line 39, in process
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_controller/metal.rb", line 190, in dispatch
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_controller/metal.rb", line 254, in dispatch
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/routing/route_set.rb", line 50, in dispatch
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/routing/route_set.rb", line 33, in serve
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/journey/router.rb", line 49, in block in serve
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/journey/router.rb", line 32, in each
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/journey/router.rb", line 32, in serve
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/routing/route_set.rb", line 834, in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/skylight-core-4.3.2/lib/skylight/core/probes/action_dispatch/routing/route_set.rb", line 14, in block in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/skylight-core-4.3.2/lib/skylight/core/fanout.rb", line 25, in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/skylight-core-4.3.2/lib/skylight/core/probes/action_dispatch/routing/route_set.rb", line 13, in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/omniauth-1.9.1/lib/omniauth/strategy.rb", line 420, in call_app!
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/omniauth-saml-1.10.3/lib/omniauth/strategies/saml.rb", line 86, in other_phase
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/omniauth-1.9.1/lib/omniauth/strategy.rb", line 190, in call!
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/omniauth-1.9.1/lib/omniauth/strategy.rb", line 169, in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/omniauth-1.9.1/lib/omniauth/builder.rb", line 45, in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/middleware/stack.rb", line 61, in block in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/notifications.rb", line 180, in block in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/notifications/instrumenter.rb", line 24, in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/notifications.rb", line 180, in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/middleware/stack.rb", line 60, in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/rack-2.2.3/lib/rack/tempfile_reaper.rb", line 15, in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/middleware/stack.rb", line 61, in block in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/notifications.rb", line 180, in block in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/notifications/instrumenter.rb", line 24, in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/activesupport-6.0.3.4/lib/active_support/notifications.rb", line 180, in instrument
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/middleware/stack.rb", line 60, in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/rack-2.2.3/lib/rack/etag.rb", line 27, in call
  File "/var/www/sites/jupiter/vendor/ruby/2.5.0/gems/actionpack-6.0.3.4/lib/action_dispatch/middleware/stack.rb", l