fix nil context in NewQuizzesFeaturesHelper placements check

There are instances where @context is undefined in the feature
helper. This updates the method to take a passed context and
default to the class define context.

fixes QUIZ-8516
flag=new_quizzes_account_course_level_item_banks

Test Plan:
1. specs pass
2. open up the broswer dev console for your local canvas
3. Run `fetch('http://canvas.docker/api/v1/courses?include[]=tabs'}`
4. You should not get an error.

Change-Id: I331e921f626651244738ca6bc7d7007f06d30d9a
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/267422
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Stephen Kacsmark <skacsmark@instructure.com>
QA-Review: Mark McDermott <mmcdermott@instructure.com>
Product-Review: Stephen Kacsmark <skacsmark@instructure.com>

app/helpers/application_helper.rb

@@ -347,7 +347,7 @@ module ApplicationHelper
       if (tab[:id] == @context.class::TAB_COLLABORATIONS rescue false)
         Collaboration.any_collaborations_configured?(@context) && !@context.feature_enabled?(:new_collaborations)
       elsif (quiz_lti_tab?(tab) rescue false)
-        new_quizzes_navigation_placements_enabled?
+        new_quizzes_navigation_placements_enabled?(@context)
       elsif (tab[:id] == @context.class::TAB_COLLABORATIONS_NEW rescue false)
         @context.feature_enabled?(:new_collaborations)
       elsif (tab[:id] == @context.class::TAB_CONFERENCES rescue false)

app/helpers/new_quizzes_features_helper.rb

@@ -35,14 +35,14 @@ module NewQuizzesFeaturesHelper
     @context.root_account.feature_enabled?(:migrate_to_new_quizzes_by_default) || new_quizzes_require_migration?
   end
 
-  def new_quizzes_navigation_placements_enabled?
-    Account.site_admin.feature_enabled?(:new_quizzes_account_course_level_item_banks) && @context.feature_enabled?(:quizzes_next)
+  def new_quizzes_navigation_placements_enabled?(context = @context)
+    Account.site_admin.feature_enabled?(:new_quizzes_account_course_level_item_banks) && context.feature_enabled?(:quizzes_next)
   end
 
   module_function
 
   def new_quizzes_enabled?(context = @context)
-      context.feature_enabled?(:quizzes_next) && context.quiz_lti_tool.present? && !new_quizzes_require_migration?(context)
+    context.feature_enabled?(:quizzes_next) && context.quiz_lti_tool.present? && !new_quizzes_require_migration?(context)
   end
 
   def new_quizzes_require_migration?(context = @context)

app/helpers/section_tab_helper.rb

@@ -112,7 +112,7 @@ module SectionTabHelper
           elsif tab_is?(tab, 'TAB_CONFERENCES')
             !WebConference.config(context: @context)
           elsif quiz_lti_tab?(tab)
-            !new_quizzes_navigation_placements_enabled?
+            !new_quizzes_navigation_placements_enabled?(context)
           end
         end
       end

lib/api/v1/tab.rb

@@ -118,7 +118,7 @@ module Api::V1::Tab
       elsif (tab[:id] == context.class::TAB_CONFERENCES rescue false)
         tab[:href] && tab[:label] && feature_enabled?(:web_conferences)
       elsif (quiz_lti_tab?(tab) rescue false)
-        tab[:href] && tab[:label] && new_quizzes_navigation_placements_enabled?
+        tab[:href] && tab[:label] && new_quizzes_navigation_placements_enabled?(context)
       else
         tab[:href] && tab[:label]
       end

spec/helpers/new_quizzes_features_helper_spec.rb

@@ -126,4 +126,31 @@ describe NewQuizzesFeaturesHelper do
       expect(new_quizzes_require_migration?).to eq true
     end
   end
+
+  describe "#new_quizzes_navigation_placements_enabled" do
+    before(:each) do
+      allow(@context).to receive(:feature_enabled?).with(:quizzes_next).and_return(true)
+      Account.site_admin.enable_feature!(:new_quizzes_account_course_level_item_banks)
+    end
+
+    it 'should be true when new_quizzes_account_course_level_item_banks and quizzes_next are true' do
+      expect(new_quizzes_navigation_placements_enabled?).to eq true
+    end
+
+    it 'should be false when new_quizzes_account_course_level_item_banks is disabled' do
+      Account.site_admin.disable_feature!(:new_quizzes_account_course_level_item_banks)
+      expect(new_quizzes_navigation_placements_enabled?).to eq false
+    end
+
+    it 'should be false when quizzes_next is disabled' do
+      allow(@context).to receive(:feature_enabled?).with(:quizzes_next).and_return(false)
+      expect(new_quizzes_navigation_placements_enabled?).to eq false
+    end
+
+    it 'should accept a context' do
+      fake_context = Course.create(name: 'fake context')
+      fake_context.disable_feature!(:quizzes_next)
+      expect(new_quizzes_navigation_placements_enabled?(fake_context)).to eq false
+    end
+  end
 end