Test programs assumptions

[Bernhard Herzog]

Martin Schulze <joey at infodrom.org> writes:

> ogclib contains class WMSClient
>
> [..]
> from ogclib import WMSClient
>
> class TestWMSClient (unittest.TestCase, WMSClient)
>       def...
>       def
> 	  skip_if_no_ogclib()
> [..]
>
> This won't work since if the class TestWMSClient cannot be created
> since WMSClient is not available.
>
> Any idea how to solve this dilemma?

Is it really necessary that TestWMSClient is a subclass of WMSClient?

You could do something like this instead:

_ogc_import_error = ""
try:
    from ogclib.WMSClient import WMSClient
except ImportError, e:
    _ogc_import_error = str(e)

def skip_if_no_ogclib():
    if _ogc_import_error:
        raise support.SkipTest(_ogc_import_error)

class TestWMSClient(unittest.TestCase):

    def setUp(self):
        skip_if_no_ogclib()

    def test_foo(self):
        client = WMSClient()
        ...


WMSClient is a mix-in class and therfore is usually used by deriving a
class from it, so it might be a bit cleaner to derive a special client
class, like it's done in the tests in PyOGCLib itself.


   Bernhard

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