delegated_auth_redirect_uri for easier testing of delegated_auth_redirect

This way we can run specs with overrides in a sane way.

test plan: n/a

Change-Id: Iffa749feb04c531a5abd6892a48e6dcd7894e8be
Reviewed-on: https://gerrit.instructure.com/7728
Tested-by: Hudson <hudson@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>

lib/authentication_methods.rb

@@ -284,7 +284,11 @@ module AuthenticationMethods
   end
 
   def delegated_auth_redirect(uri)
-    redirect_to(uri)
+    redirect_to(delegated_auth_redirect_uri(uri))
+  end
+
+  def delegated_auth_redirect_uri(uri)
+    uri
   end
 
   # if true, the user is currently stepping through the oauth2 flow for the canvas api

spec/apis/oauth_spec.rb

@@ -211,7 +211,7 @@ describe "OAuth2", :type => :integration do
         CASClient::Client.stubs(:new).returns(cas)
 
         get response['Location']
-        response.should redirect_to(cas.add_service_to_login_url(login_url))
+        response.should redirect_to(@controller.delegated_auth_redirect_uri(cas.add_service_to_login_url(login_url)))
 
         get '/login', :ticket => 'ST-abcd'
         response.should be_redirect

spec/controllers/accounts_controller_spec.rb

@@ -215,7 +215,7 @@ describe AccountsController do
     config = { :cas_base_url => account.account_authorization_config.auth_base }
     cas_client = CASClient::Client.new(config)
     get 'show', :id => account.id
-    response.should redirect_to(cas_client.add_service_to_login_url(login_url))
+    response.should redirect_to(@controller.delegated_auth_redirect_uri(cas_client.add_service_to_login_url(login_url)))
   end
 
   it "should count total courses correctly" do