Need a way to set session user ID for testing

api_v3_ActivityTest::testActivityCreateWithMissingContactId fails due to there not being a userID in the session

if ( !CRM_Utils_Array::value('source_contact_id',$params ))

{ $session = CRM_Core_Session::singleton( ); $params['source_contact_id'] = $session->get( 'userID' ); }

We need a way to force session to hold specific variables (contact_id in this case & presumably uf_id) for testing purposes.

Note that I also want to call this from my drupal tests - I am using simpletest to test custom code as that allows me to test with the combination of modules on my site (rules etc). I doubt this has any bearing on the fix though.