transform id columns when calling pluck on array

Change-Id: I0c8e8417bcead9d9e1243dabae1444fae3e3634b
Reviewed-on: https://gerrit.instructure.com/150278
Reviewed-by: Mysti Sadler <mysti@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
Tested-by: Jenkins
Product-Review: James Williams  <jamesw@instructure.com>
QA-Review: James Williams  <jamesw@instructure.com>

config/initializers/active_support.rb

@@ -105,3 +105,13 @@ module RaiseErrorOnDurationCoercion
   end
 end
 ActiveSupport::Duration.prepend(RaiseErrorOnDurationCoercion)
+
+module Enumerable
+  def pluck(*keys)
+    if keys.many?
+      map { |o| keys.map { |key| o.is_a?(ActiveRecord::Base) ? o.send(key) : o[key] } }
+    else
+      map { |o| o.is_a?(ActiveRecord::Base) ? o.send(keys.first) : o[keys.first] }
+    end
+  end
+end

spec/initializers/active_support_spec.rb

@@ -15,7 +15,7 @@
 # You should have received a copy of the GNU Affero General Public License along
 # with this program. If not, see <http://www.gnu.org/licenses/>.
 
-require_relative "../spec_helper"
+require_relative "../sharding_spec_helper"
 
 describe 'ActiveSupport::JSON' do
   it "encodes hash keys correctly" do
@@ -28,3 +28,14 @@ describe ActiveSupport::TimeZone do
     expect(ActiveSupport::TimeZone['America/Denver'].to_json).to eq "America/Denver".to_json
   end
 end
+
+describe "enumerable pluck extension" do
+  specs_require_sharding
+
+  it "should transform ids" do
+    u = User.create!
+    @shard1.activate do
+      expect([u].pluck(:id)).to eq [u.global_id]
+    end
+  end
+end