Add paste visibility option for completed only (#588)

* Add paste visibility option for completed only

* Restrict protected/secured paste_visibility option

Author: Redande

app/controllers/submissions_controller.rb

@@ -317,15 +317,17 @@ def check_access!
       end
 
       paste_visible = @submission.paste_visible_for?(current_user)
-      return if paste_visible
+
       paste_visibility = @exercise.paste_visibility
       paste_visibility ||= @course.paste_visibility
       paste_visibility ||= 'open'
       case paste_visibility
       when 'protected', 'secured'
-        respond_forbidden unless can?(:teach, @course) || @submission.user_id.to_s == current_user.id.to_s || paste_visible
+        respond_forbidden unless can?(:teach, @course) || @submission.user_id.to_s == current_user.id.to_s
       when 'no-tests-public'
         respond_forbidden unless can?(:teach, @course) || @submission.created_at > 2.hours.ago || @submission.user_id.to_s == current_user.id.to_s
+      when 'completed-only'
+        respond_forbidden("You cannot see this paste because you haven't completed this exercise.") unless can?(:teach, @course) || @submission.user_id.to_s == current_user.id.to_s || @submission.exercise.completed_by?(current_user) || current_user.submissions.where(exercise_name: @exercise.name, pretest_error: nil, all_tests_passed: true).any?
       when 'everyone'
         nil
       else

app/models/course.rb

@@ -189,7 +189,7 @@ def links_as_json(view_context)
   scope :with_certificates_for, ->(user) { select { |c| c.visible_to?(user) && c.certificate_downloadable_for?(user) } }
 
   enum disabled_status: %i[enabled disabled]
-  enum paste_visibility: %i[open secured no-tests-public everyone]
+  enum paste_visibility: %i[open secured no-tests-public everyone completed-only]
 
   def destroy
     # Optimization: delete dependent objects quickly.

app/models/exercise.rb

@@ -122,7 +122,7 @@ class Exercise < ApplicationRecord
   }
 
   enum disabled_status: %i[enabled disabled]
-  enum paste_visibility: %i[open secured no-tests-public everyone]
+  enum paste_visibility: %i[open secured no-tests-public everyone completed-only]
 
   def relative_path
     name.tr('-', '/')