PyDev unittesting: How to capture text logged to a logging.Logger in “Captured Output”

Question

I am using PyDev for development and unit-testing of my Python application. As for unit-testing, everything works great except the fact that no content is logged to the logg

Answer 1

I grew tired of having to manually add Fabio's great code to all setUps, so I subclassed unittest.TestCase with some __metaclass__ing:

class LoggedTestCase(unittest.TestCase):
    __metaclass__ = LogThisTestCase
    logger = logging.getLogger("unittestLogger")
    logger.setLevel(logging.DEBUG) # or whatever you prefer

class LogThisTestCase(type):
    def __new__(cls, name, bases, dct):
        # if the TestCase already provides setUp, wrap it
        if 'setUp' in dct:
            setUp = dct['setUp']
        else:
            setUp = lambda self: None
            print "creating setUp..."

        def wrappedSetUp(self):
            # for hdlr in self.logger.handlers:
            #    self.logger.removeHandler(hdlr)
            self.hdlr = logging.StreamHandler(sys.stdout)
            self.logger.addHandler(self.hdlr)
            setUp(self)
        dct['setUp'] = wrappedSetUp

        # same for tearDown
        if 'tearDown' in dct:
            tearDown = dct['tearDown']
        else:
            tearDown = lambda self: None

        def wrappedTearDown(self):
            tearDown(self)
            self.logger.removeHandler(self.hdlr)
        dct['tearDown'] = wrappedTearDown

        # return the class instance with the replaced setUp/tearDown
        return type.__new__(cls, name, bases, dct)

Now your test case can simply inherit from LoggedTestCase, i.e. class TestCase(LoggedTestCase) instead of class TestCase(unittest.TestCase) and you're done. Alternatively, you can add the __metaclass__ line and define the logger either in the test or a slightly modified LogThisTestCase.