new Class().Function() pattern

Question

I am maintaining an application and have seen something like this

Permission p = new UserModel().GetPermission(userToTestPerrmission, permissionWeCheck);
if(p.CanChange)
   //sometihing
else
   //something else

This approach looks a little "dirty" to me. The part I have problems with is this new UserModel().GetPermission(). Is this a typical way to write something like this or should it be like:

var model = new UserModel();
model.GetPermissions(...);
...

Answer 1

Is this a typical way to write something like

If that’s all the information that is required – yes, why not? I see no problem at all with this approach.

On the other hand, if code lik this is prolific this is a sure sign that the original class design is broken. But from your code it looks like this is outside of your control anyway, since UserModel is a framework class.

In general, if a class is used in such a fashion then it is over-engineered: a static method could have been used just as well (on the other hand, this may make unit testing harder because it prevents mocking).