Wrapping other async tasks

wrapping-with-when.js

// assume that getUsers returns a promise but
// the service may not be written in angular
$q.when(service.getUsers()).then(function(result) {
    ctrl.userList = result;
});

// $q.when() can also be useful when writing stubs
function getUsers() {
    // this function is supposed to return a promise
    // but in test, it doesn't make sense to do that
    // so use $q.when() to return an immediately
    // resolving promise.
    return $q.when(_userList);
}