Question

I’m trying to be better about unit testing my code, but right now I’m writing a lot of code that deals with remote systems. SNMP, WMI, that sort of thing. With most classes I can mock up objects to test them, but how do you deal with unit testing a real system? For example, if my class goes out and gets the Win32_LogicalDisk object for a server, how could I possibly unit test it?

Answer 1

Assuming you meant ‘How do I test against things that are hard/impossible to mock’:

If you have a class that ‘goes out and gets the Win32_LogicalDisk object for a server’ AND does something else (consumes the ‘Win32_LogicalDisk’ object in some way), assuming you want to test the pieces of the class that consume this object, you can use Dependency Injection to allow you to mock the ‘Win32_LogicalDisk’ object. For instance:

class LogicalDiskConsumer(object):      def __init__(self, arg1, arg2, LogicalDiskFactory)         self.arg1=arg1         self.arg2=arg2         self.LogicalDisk=LogicalDiskFactory()      def consumedisk(self):         self.LogicalDisk.someaction() 

Then in your unit test code, pass in a ‘LogicalDiskFactory’ that returns a mock object for the ‘Win32_LogicalDisk’.