pytest and coverage combination does not work

Question

I installed plugin for pytest from here:http://pypi.python.org/pypi/pytest-cov. Then I have a simple test code:

pytest.py:

class TestNumbers:
    def test_int_float(self):
        assert 1 == 1.0

    def test_int_str(self):
        assert 1 == 1

I tried to test it with command: 'py.test --cov-report term --cov pytest.py'. But it doesn't work. Even if I gave the entire absolute path of pytest.py it was still no data for collecting. However if I use py.test pytest.py, surely it tested Ok.

I am very confusing about this problem, thanks for help.

Solution

Try:

py.test --cov-report term --cov=. test.py

The --cov parameter takes an argument saying which paths to cover. In your example, --cov would consume test.py, but then there were no arguments left for py.test about which files to test.

UPDATE: as @hpk42 points out, you need to call your example something other than pytest.py. When I did this locally, I called it test.py instead.

Comments

[hpk42]

If "pytest.py" is the user-module, it will not work. It shadows the the actual py.test (because you do "import pytest" to import helpers/things).

[John Szakmeister]

Whups... that was meant to be test.py in my example. You're absolutely right of course. py.test does at least output a decent error message informing you of this problem though.

[user1067671]

Thank you so much. The problem is that used 'pytest.py' as filename. After change it all tests went through Ok. You answer is right. Command should be "py.test --cov-report term --cov=. test.py"

[floer_m]

If anybody's wondering how to get coverage numbers from doctests (A coworker of mine thought this wasn't supported) -- $ py.test --doctest-modules . --cov-report term --cov=. or $ py.test --doctest-modules mymodule --cov-report term --cov=mymodule