Add course pacing item to the course navigation menu

closes LS-3546
flag = course_paces

Test plan:
 - Open a course with course pacing enabled as a teacher
 - Expect a 'Course Pacing' item in the course navigation
 - Expect no 'Course Pacing' button on the modules page
 - Disable course pacing or login as a student and expect to not
   see the Course pacing nav item

Change-Id: Iac8423a6a565c1761cfc1f0211822938bf61a6ea
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/303986
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Eric Saupe <eric.saupe@instructure.com>
QA-Review: Eric Saupe <eric.saupe@instructure.com>
Product-Review: Luis Oliveira <luis.oliveira@instructure.com>

app/models/course.rb

@@ -3012,6 +3012,7 @@ class Course < ActiveRecord::Base
   TAB_COLLABORATIONS_NEW = 17
   TAB_RUBRICS = 18
   TAB_SCHEDULE = 19
+  TAB_COURSE_PACES = 20
 
   CANVAS_K6_TAB_IDS = [TAB_HOME, TAB_ANNOUNCEMENTS, TAB_GRADES, TAB_MODULES].freeze
   COURSE_SUBJECT_TAB_IDS = [TAB_HOME, TAB_SCHEDULE, TAB_MODULES, TAB_GRADES, TAB_GROUPS].freeze
@@ -3179,6 +3180,16 @@ class Course < ActiveRecord::Base
                    else
                      Course.default_tabs
                    end
+
+    if account.feature_enabled?(:course_paces) && enable_course_paces && grants_any_right?(user, :manage_content, *RoleOverride::GRANULAR_MANAGE_COURSE_CONTENT_PERMISSIONS)
+      default_tabs.insert(default_tabs.index { |t| t[:id] == TAB_MODULES } + 1, {
+                            id: TAB_COURSE_PACES,
+                            label: t("#tabs.course_paces", "Course Pacing"),
+                            css_class: "course_paces",
+                            href: :course_course_pacing_path
+                          })
+    end
+
     opts[:include_external] = false if elementary_homeroom_course?
 
     GuardRail.activate(:secondary) do

app/views/context_modules/_content_next.html.erb

@@ -56,9 +56,6 @@
           </button>
         <% end %>
       <% end %>
-      <% if @context.account.feature_enabled?(:course_paces) && @context.enable_course_paces && @context.grants_any_right?(@current_user, session, :manage_content, *RoleOverride::GRANULAR_MANAGE_COURSE_CONTENT_PERMISSIONS) %>
-        <a class="btn" id="course_paces_link" href="<%= course_course_pacing_path(@context) %>"><%= t("Course Pacing") %></a>
-      <% end %>
       <% if @can_add %>
         <button class="btn btn-primary add_module_link">
           <i class="icon-plus" role="presentation"></i>

spec/models/course_spec.rb

@@ -2792,6 +2792,32 @@ describe Course do
         end
       end
 
+      describe "TAB_COURSE_PACES" do
+        it "is included when course paces is enabled" do
+          @course.account.enable_feature!(:course_paces)
+          @course.enable_course_paces = true
+          @course.save!
+          tabs = @course.tabs_available(@user).pluck(:id)
+          expect(tabs).to include(Course::TAB_COURSE_PACES)
+        end
+
+        it "is not included if the flag is off" do
+          @course.account.disable_feature!(:course_paces)
+          @course.enable_course_paces = true
+          @course.save!
+          tabs = @course.tabs_available(@user).pluck(:id)
+          expect(tabs).not_to include(Course::TAB_COURSE_PACES)
+        end
+
+        it "is not included if the course has it disabled" do
+          @course.account.enable_feature!(:course_paces)
+          @course.enable_course_paces = false
+          @course.save!
+          tabs = @course.tabs_available(@user).pluck(:id)
+          expect(tabs).not_to include(Course::TAB_COURSE_PACES)
+        end
+      end
+
       it "returns the defaults if nothing specified" do
         tab_ids = @course.tabs_available(@user).pluck(:id)
         expect(tab_ids).to eql(default_tab_ids)
@@ -3164,6 +3190,16 @@ describe Course do
         course_with_student(active_all: true)
       end
 
+      describe "TAB_COURSE_PACES" do
+        it "is not included" do
+          @course.account.enable_feature!(:course_paces)
+          @course.enable_course_paces = true
+          @course.save!
+          tabs = @course.tabs_available(@user).pluck(:id)
+          expect(tabs).not_to include(Course::TAB_COURSE_PACES)
+        end
+      end
+
       it "returns K-6 tabs if feature flag is enabled for students" do
         @course.enable_feature!(:canvas_k6_theme)
         tab_ids = @course.tabs_available(@user).pluck(:id)

spec/selenium/course_paces/coursepaces_spec.rb

@@ -50,13 +50,6 @@ describe "course pace page" do
 
       expect(driver.current_url).to include("/courses/#{@course.id}/course_pacing")
     end
-
-    it "is not shown when disabled" do
-      disable_course_paces_in_course
-      get "/courses/#{@course.id}/modules"
-
-      expect(course_paces_nav_exists?).to be_falsey
-    end
   end
 
   context "course paces modules" do

spec/selenium/courses/pages/courses_home_page.rb

@@ -48,7 +48,7 @@ module CoursesHomePage
   end
 
   def course_course_pace_selector
-    "#course_paces_link"
+    ".course_paces"
   end
 
   def course_menu_toggle_selector