Add a helper to stub authorization when visiting backend pages

For some reason the core authorization helper is not working.

admin/spec/features/accounts_spec.rb

@@ -5,6 +5,7 @@
 describe "Accounts", type: :feature do
   it "shows account info" do
     user = create(:admin_user, email: '[email protected]')
+    stub_authorization! user
     sign_in user
 
     visit "/admin/account"

admin/spec/support/solidus_admin/feature_helpers.rb

@@ -3,5 +3,16 @@ module FeatureHelpers
     def sign_in(user)
       allow_any_instance_of(SolidusAdmin::BaseController).to receive(:spree_current_user).and_return(user)
     end
+
+    def stub_authorization!(user)
+      ability = Spree::Ability.new(user)
+      if block_given?
+        yield ability
+      else
+        ability.can :manage, :all
+      end
+      allow_any_instance_of(SolidusAdmin::BaseController).to receive(:current_ability).and_return(ability)
+      allow_any_instance_of(Spree::Admin::BaseController).to receive(:current_ability).and_return(ability)
+    end
   end
 end