unit test roll die

[stullis]

In test_die(), mock.patch() isn't being used in your with statements. When using "with", you need to assign the operation as a variable and reference that variable in the following code body. From the documentation:

with patch('__main__.Class') as MockClass:
    instance = MockClass.return_value
    instance.method.return_value = 'foo'
    assert Class() is instance
    assert Class().method() == 'foo'

In test_die on line 8, there will be an assertion error because rolldie.run() does not return a range object. Your next two assertions would work because those strings are returned by rolldie.run(). A proper test passes a known value to a function/method and validates that the returned value matches expectations.

The third problem I see is that rolldie.run() isn't supportive of testing because of the input() calls. In fact, that's likely why it's freezing; rolldie.run() isn't receiving the inputs it wants so the program cannot move forward. Unit tests are best used with functions that return a value. I rewrote the code to support unit testing though there isn't really enough there to test:

from random import randint

def run():
    while True:
        num = integer_input("Enter an number to roll: ")

        if validate(num):
            return "Game terminated"

        roll = randint(1,6)
        print(format_result(roll))

def integer_input(message):
    while True:
        try:
            x = int(input(message))
            return x
        except ValueError:
            print("\nInvalid value, please enter an integer.")

def validate(num):
    return num == 0

def format_result(num):
    return f"Result {num}"

With that code, you could test both validate() and format_result() because they have predictable outputs with known inputs. So, you could ensure that validate returns True if a 0 is passed in or that "Result 5" is returned by format_result is a 5 is provided. However, we already know those would work since those functions merely do basic behaviors of Python.