How can I write test cases for operations performed on the randomly generated numpy array?

I have a numpy array generated using the random function.

n = [43, 20, 15, 29, 11]

Function do_something(n) takes numpy array as parameter and returns the result after performing the operation.

result = do_something(n)

How can I write the test cases for the function do_something(n) and verify the expected and actual result?