Python: How to run unittest.main() for all source files in a subdirectory?

I am developing a Python module with several source files, each with its own test class derived from unittest right in the source. Consider the directory structure:

dirFoo\
    test.py
    dirBar\
        __init__.py
        Foo.py
        Bar.py

To test either Foo.py or Bar.py, I would add this at the end of the Foo.py and Bar.py source files:

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

And run Python on either source, i.e.

$ python Foo.py
...........
----------------------------------------------------------------------
Ran 11 tests in 2.314s

OK

Ideally, I would have "test.py" automagically search dirBar for any unittest derived classes and make one call to "unittest.main()". What's the best way to do this in practice?

I tried using Python to call execfile for every *.py file in dirBar, which runs once for the first .py file found & exits the calling test.py, plus then I have to duplicate my code by adding unittest.main() in every source file--which violates DRY principles.

Solution 1:

As of Python 2.7, test discovery is automated in the unittest package. From the docs:

Unittest supports simple test discovery. In order to be compatible with test discovery, all of the test files must be modules or packages importable from the top-level directory of the project (this means that their filenames must be valid identifiers).

Test discovery is implemented in TestLoader.discover(), but can also be used from the command line. The basic command-line usage is:

cd project_directory
python -m unittest discover

By default it looks for packages named test*.py, but this can be changed so you might use something like

python -m unittest discover --pattern=*.py

In place of your test.py script.

Solution 2:

Here is my test discovery code that seems to do the job. I wanted to make sure I can extend the tests easily without having to list them in any of the involved files, but also avoid writing all tests in one single Übertest file.

So the structure is

myTests.py
testDir\
    __init__.py
    testA.py
    testB.py

myTest.py look like this:

import unittest

if __name__ == '__main__':
    testsuite = unittest.TestLoader().discover('.')
    unittest.TextTestRunner(verbosity=1).run(testsuite)

I believe this is the simplest solution for writing several test cases in one directory. The solution requires Python 2.7 or Python 3.

Solution 3:

I knew there was an obvious solution:

dirFoo\
    __init__.py
    test.py
    dirBar\
        __init__.py
        Foo.py
        Bar.py

Contents of dirFoo/test.py

from dirBar import *
import unittest

if __name__ == "__main__":

    unittest.main()

Run the tests:

$ python test.py
...........
----------------------------------------------------------------------
Ran 11 tests in 2.305s

OK

Solution 4:

You should try nose. It's a library to help create tests and it integrates with unittest or doctest. All you need to do is run nosetests and it'll find all your unittests for you.

% nosetests # finds all tests in all subdirectories
% nosetests tests/ # find all tests in the tests directory

Solution 5:

In case it happens to help anyone, here is the approach I arrived at for solving this problem. I had the use case where I have the following directory structure:

mypackage/
    tests/
        test_category_1/
            tests_1a.py
            tests_1b.py
            ...
        test_category_2/
            tests_2a.py
            tests_2b.py
            ...
        ...

and I want all of the following to work in the obvious way and to be able to be supplied the same commandline arguments as are accepted by unittest:

python -m mypackage.tests
python -m mypackage.tests.test_category_1
python -m mypackage.tests.test_category_1.tests_1a

The solution was to set up mypackage/tests/__init__.py like this:

import unittest

def prepare_load_tests_function (the__path__):
    test_suite = unittest.TestLoader().discover(the__path__[0])
    def load_tests (_a, _b, _c):
        return test_suite
    return load_tests

and to set up mypackage/tests/__main__.py like this:

import unittest
from . import prepare_load_tests_function, __path__

load_tests = prepare_load_tests_function(__path__)
unittest.main()

and to copy and paste an empty __init__.py and the following __main__.py in each mypackage/tests/test_category_n/:

import unittest
from .. import prepare_load_tests_function
from . import __path__

load_tests = prepare_load_tests_function(__path__)
unittest.main()

and also to add the standard if __name__ == '__main__': unittest.main() in each actual tests file.

(Works for me on Python 3.3 on Windows, ymmv.)