RuboCop: Style/EmptyCaseCondition

some auto, some manual if there was a better fitting construct than
an if/elsif/else

Change-Id: Ifee268f80d411b7b4c98a024c209d2014c7d0c9f
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/277998
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Simon Williams <simon@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>

.rubocop.common.yml

@@ -132,6 +132,8 @@ Style/ConditionalAssignment:
   Severity: error
 Style/Documentation:
   Enabled: false # most things don't need to be documented
+Style/EmptyCaseCondition:
+  Severity: error
 Style/Encoding:
   Severity: error
 Style/FrozenStringLiteralComment:

app/controllers/calendar_events_api_controller.rb

@@ -804,12 +804,12 @@ class CalendarEventsApiController < ApplicationController
     respond_to do |format|
       format.ics do
         name = t('ics_title', "%{course_or_group_name} Calendar (Canvas)", :course_or_group_name => @context.name)
-        description = case
-                      when @context.is_a?(Course)
+        description = case @context
+                      when Course
                         t('ics_description_course', "Calendar events for the course, %{course_name}", :course_name => @context.name)
-                      when @context.is_a?(Group)
+                      when Group
                         t('ics_description_group', "Calendar events for the group, %{group_name}", :group_name => @context.name)
-                      when @context.is_a?(User)
+                      when User
                         t('ics_description_user', "Calendar events for the user, %{user_name}", :user_name => @context.name)
                       else
                         t('ics_description', "Calendar events for %{context_name}", :context_name => @context.name)

app/controllers/pseudonyms_controller.rb

@@ -286,12 +286,7 @@ class PseudonymsController < ApplicationController
 
   def get_user
     user_id = params[:user_id] || params[:user].try(:[], :id)
-    @user = case
-            when user_id
-              api_find(User, user_id)
-            else
-              @current_user
-            end
+    @user = user_id ? api_find(User, user_id) : @current_user
     true
   end
   protected :get_user

app/controllers/submissions_controller.rb

@@ -305,10 +305,9 @@ class SubmissionsController < SubmissionsBaseController
         log_asset_access(@assignment, "assignments", @assignment_group, 'submit')
         format.html do
           flash[:notice] = t('assignment_submit_success', 'Assignment successfully submitted.')
-          tardiness = case
-                      when @submission.late?
+          tardiness = if @submission.late?
                         2 # late
-                      when @submission.cached_due_date.nil?
+                      elsif @submission.cached_due_date.nil?
                         0 # don't know
                       else
                         1 # on time

app/models/alert.rb

@@ -41,14 +41,14 @@ class Alert < ActiveRecord::Base
     include_teachers = false
     admin_role_ids = []
     self.recipients.try(:each) do |recipient|
-      case
-      when recipient == :student
+      case recipient
+      when :student
         include_student = true
-      when recipient == :teachers
+      when :teachers
         include_teachers = true
-      when recipient.is_a?(String)
+      when String
         admin_role_ids << find_role_by_name(recipient).id
-      when recipient.is_a?(Hash)
+      when Hash
         admin_role_ids << recipient[:role_id]
       else
         raise "Unsupported recipient type!"

app/models/discussion_topic.rb

@@ -597,12 +597,11 @@ class DiscussionTopic < ActiveRecord::Base
   def subscription_hold(user, session)
     return nil unless user
 
-    case
-    when initial_post_required?(user, session)
+    if initial_post_required?(user, session)
       :initial_post_required
-    when root_topic? && !child_topic_for(user)
+    elsif root_topic? && !child_topic_for(user)
       :not_in_group_set
-    when context.is_a?(Group) && !context.has_member?(user)
+    elsif context.is_a?(Group) && !context.has_member?(user)
       :not_in_group
     end
   end

gems/attachment_fu/lib/attachment_fu.rb

@@ -159,14 +159,9 @@ module AttachmentFu # :nodoc:
     end
 
     def load_related_exception?(e) # :nodoc: implementation specific
-      case
-      when e.kind_of?(LoadError), e.kind_of?(MissingSourceFile), $!.class.name == "CompilationError"
-        # We can't rescue CompilationError directly, as it is part of the RubyInline library.
-        # We must instead rescue RuntimeError, and check the class' name.
-        true
-      else
-        false
-      end
+      # We can't rescue CompilationError directly, as it is part of the RubyInline library.
+      # We must instead rescue RuntimeError, and check the class' name.
+      e.is_a?(LoadError) || e.is_a?(MissingSourceFile) || e.instance_of?(CompilationError)
     end
     private :load_related_exception?
   end

spec/selenium/helpers/conversations_common.rb

@@ -228,18 +228,18 @@ module ConversationsCommon
 
   # Allows you to select between
   def click_more_options(opts, message = 0)
-    case
     # First case is for clicking on message gear menu
-    when opts[:message]
+    if opts[:message]
       # The More Options gear menu only shows up on mouse over of message
       driver.action.move_to(ff('.message-item-view')[message]).perform
       wait_for_ajaximations
       f('.actions li .inline-block .al-trigger').click
     # This case is for clicking on gear menu at conversation heading level
-    when opts[:convo]
+    elsif opts[:convo]
       f('.message-header .al-trigger').click
     # Otherwise, it clicks the topmost gear menu
-    else f('#admin-btn.al-trigger').click
+    else
+      f('#admin-btn.al-trigger').click
     end
     wait_for_ajaximations
   end