[Python-Dev] Socket servers in the test suite

[Nick Coghlan]

On Thu, Apr 28, 2011 at 7:23 AM, Vinay Sajip <vinay_sajip at yahoo.co.uk> wrote:
> I've been recently trying to improve the test coverage for the logging package,
> and have got to a not unreasonable point:
>
> logging/__init__.py 99% (96%)
> logging/config.py 89% (85%)
> logging/handlers.py 60% (54%)
>
> where the figures in parentheses include branch coverage measurements.
>
> I'm at the point where to appreciably increase coverage, I'd need to write some
> test servers to exercise client code in SocketHandler, DatagramHandler and
> HTTPHandler.
>
> I notice there are no utility classes in test.support to help with this kind of
> thing - would there be any mileage in adding such things? Of course I could add
> test server code just to test_logging (which already contains some socket server
> code to exercise the configuration functionality), but rolling a test server
> involves boilerplate such as using a custom RequestHandler-derived class for
> each application. I had in mind a more streamlined approach where you can just
> pass a single callable to a server to handle requests, e.g. as outlined in
>
> https://gist.github.com/945157
>
> I'd be grateful for any comments about adding such functionality to e.g.
> test.support.

If you poke around in the test directory a bit, you may find there is
already some code along these lines in other tests (e.g. I'm pretty
sure the urllib tests already fire up a local server). Starting down
the path of standardisation of that test functionality would be good.

For larger components like this, it's also reasonable to add a
dedicated helper module rather than using test.support directly. I
started (and Antoine improved) something along those lines with the
test.script_helper module for running Python subprocesses and checking
their output, although it lacks documentation and there are lots of
older tests that still use subprocess directly.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia