Question

I am about to make a game using python and libtcod roguelike game library.

More to the point, I am using PyMock because I am just starting to learn Test-Driven Development, and I am determined not to cheat. I really want to get into the habit of doing it properly, and according to TDD I need a failing unit test before I write my first line of code.

I figure my first test of my “production” code should be that its dependency, libcotdpy, is imported.

My testing file:

#!/usr/bin/python
import pymock   # for mocking and unit testing
import game     # my (empty) production code file, game.py

class InitializeTest(pymock.PyMockTestCase):
    def test_libtcod_is_imported(self):
        # How do I test that my production file imports the libtcodpy module?

if __name__=="__main__":
    import unittest
    unittest.main()

Please:

1) (python people) How do I test that the module is loaded?

2) (TDD people) Should I be unit testing something this basic? If not, what is the first thing I should be testing?

Answer 1

1) 'your_module' in sys.modules.
Don’t actually use that, though:

2)
What should your library should do?
Is it “have a dependency on libcotdpy”? I think not.

You’ve just made a design choice that wasn’t test-driven!

Write a test that demonstrates how you want to use the library. Don’t think about how you’re going to implement it. For example:

player = my_lib.PlayerCharacter()
assert player.position == (0, 0)  # or whatever assert syntax `pymock` uses
press_key('k')
assert player.position == (0, 1)

Or something similar. (I don’t know what you want your library to do, or how much libtcod provides.)