clear cached context short names after update

test plan:
* add a rubric to a course
* update the course's course code
* use the "find rubric" to add an existing
 rubric to an assignment
* the course code listed on the left side
 should match the new course code

closes #OUT-1781

Change-Id: Iebc77716ecfef90ae9e099367c2305314dbf265e
Reviewed-on: https://gerrit.instructure.com/136576
Tested-by: Jenkins
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
QA-Review: Andrew Porter <hporter-c@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>

app/models/account.rb

@@ -108,6 +108,8 @@ class Account < ActiveRecord::Base
   after_save :invalidate_caches_if_changed
   after_update :clear_special_account_cache_if_special
 
+  after_update :clear_cached_short_name, :if => :name_changed?
+
   after_create :create_default_objects
 
   serialize :settings, Hash

app/models/context.rb

@@ -54,6 +54,12 @@ module Context
       Eportfolio: :Eportfolio
   }.freeze
 
+  def clear_cached_short_name
+    self.class.connection.after_transaction_commit do
+      Rails.cache.delete(['short_name_lookup', self.asset_string].cache_key)
+    end
+  end
+
   def add_aggregate_entries(entries, feed)
     entries.each do |entry|
       user = entry.user || feed.user

app/models/course.rb

@@ -209,6 +209,8 @@ class Course < ActiveRecord::Base
   after_save :set_self_enrollment_code
   after_commit :update_cached_due_dates
 
+  after_update :clear_cached_short_name, :if => :course_code_changed?
+
   before_update :handle_syllabus_changes_for_master_migration
 
   before_save :touch_root_folder_if_necessary

app/models/group.rb

@@ -71,6 +71,8 @@ class Group < ActiveRecord::Base
 
   after_create :refresh_group_discussion_topics
 
+  after_update :clear_cached_short_name, :if => :name_changed?
+
   delegate :time_zone, :to => :context
 
   include StickySisFields

app/models/stream_item.rb

@@ -207,7 +207,7 @@ class StreamItem < ActiveRecord::Base
       raise "Unexpected stream item type: #{object.class}"
     end
     if self.context_type
-      res['context_short_name'] = Rails.cache.fetch(['short_name_lookup', self.context_type, self.context_id].cache_key) do
+      res['context_short_name'] = Rails.cache.fetch(['short_name_lookup', "#{self.context_type.underscore}_#{self.context_id}"].cache_key) do
         self.context.short_name rescue ''
       end
     end

app/models/user.rb

@@ -36,6 +36,8 @@ class User < ActiveRecord::Base
 
   before_save :infer_defaults
   after_create :set_default_feature_flags
+  after_update :clear_cached_short_name, if: -> (user) {user.short_name_changed? || (user.read_attribute(:short_name).nil? && user.name_changed?)}
+
   serialize :preferences
   include TimeZoneHelper
   time_zone_attribute :time_zone

spec/models/stream_item_spec.rb

@@ -54,6 +54,23 @@ describe StreamItem do
     expect(de.reload.discussion_topic_id).not_to be_nil
   end
 
+  it "uses new context short name" do
+    user_factory
+    context = Course.create!(:course_code => "some name")
+    enable_cache do
+      dt1 = DiscussionTopic.create!(:context => context)
+      dt1.generate_stream_items([@user])
+      si1 = StreamItem.where(:asset_id => dt1.id).first
+      expect(si1.data.context_short_name).to eq "some name"
+
+      context.update_attribute(:course_code, "some other name")
+      dt2 = DiscussionTopic.create!(:context => context)
+      dt2.generate_stream_items([@user])
+      si2 = StreamItem.where(:asset_id => dt2.id).first
+      expect(si2.data.context_short_name).to eq "some other name"
+    end
+  end
+
   describe "destroy_stream_items_using_setting" do
     it "should have a default ttl" do
       si1 = StreamItem.create! { |si| si.asset_type = 'Message'; si.data = { notification_id: nil } }