In part 1, I went over the module structure of a simple module, and a summary of the unit tests I would execute. In this post, I cover the actual nose tests.
1. Test module arguments
Mocking is important to unit testing Ansible modules. It took me a while and several videos to understand how Python Mock works. Do not pull your hair out if you do not get it the first time around.
mock.patch has a quirk that took a while to get used to. Notice that check_if_route_exists and AnsibleModule is mocked in that order. But in the test_module_args call, variables holding those mocks are in reverse order. the order is reversed, that is mock_modules first, followed by mock_route_check..Weird!
2. Test Exit functionality
In these tests, the “check route found” mocked function has a return value.
This needs to be set before the prefix_check.main() function is called.
I broke out the success and failure test case into 2 separate functions, just
to make it clear what I’m doing. Normally, I’m lazy and just keep my test cases
in the same function and use reset_mock() to reinitialize the mocks before each use case. Probably bad practise though :)
Test route check function
The hardest trick in these tests was mocking the time.sleep function. Wanted to be
sure that it polls ip route show correctly.
The final test, ensures that future modifications don’t mess up the ip route show call.
In part 3, I show how I run the tests.