fix sub account cache invalidation

Change-Id: Icb7f6ef46f1c913f3e0a0018e43ba3a59c12012a
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/250387
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Rob Orton <rob@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>

app/models/account.rb

@@ -732,13 +732,13 @@ class Account < ActiveRecord::Base
   end
 
   def invalidate_caches_if_changed
-    if changed?
-      connection.after_transaction_commit do
-        if root_account?
-          Account.invalidate_cache(id)
-        else
-          shard.activate do
-            Rails.cache.delete(["account"/ id].cache_key)
+    if saved_changes?
+      shard.activate do
+        self.class.connection.after_transaction_commit do
+          if root_account?
+            Account.invalidate_cache(id)
+          else
+            Rails.cache.delete(["account2", id].cache_key)
           end
         end
       end

lib/canvas/account_cacher.rb

@@ -20,7 +20,7 @@ module Canvas
   module AccountCacher
     class CacheAccountOnAssociation < ActiveRecord::Associations::BelongsToAssociation
       def find_target
-        key = ["account", owner._read_attribute(reflection.foreign_key)].cache_key
+        key = ["account2", owner._read_attribute(reflection.foreign_key)].cache_key
         return RequestCache.cache([Switchman::Shard.current.id, key].cache_key) { Rails.cache.fetch(key) { super } }
       end  
     end

spec/models/account_spec.rb

@@ -2116,4 +2116,20 @@ describe Account do
       ).to eq %w[AccountAdmin AssistantGrader DesignerEnrollment TeacherEnrollment]
     end
   end
+
+  describe '#invalidate_caches_if_changed' do
+    it 'works for root accounts' do
+      Account.default.name = 'Something new'
+      expect(Account).to receive(:invalidate_cache).with(Account.default.id).at_least(1)
+      Account.default.save!
+    end
+
+    it 'works for sub accounts' do
+      a = Account.default.manually_created_courses_account
+      a.name = 'something else'
+      expect(Rails.cache).to receive(:delete).with("short_name_lookup/account_#{a.id}").ordered
+      expect(Rails.cache).to receive(:delete).with(["account2", a.id].cache_key).ordered
+      a.save!
+    end
+  end
 end