[Dev] Mock Reactor for tests?

[Phillip J. Eby]

At 11:59 AM 6/6/2005 -0700, Brian Kirsch wrote:
>Hi Phillip,
>I am not sure if we really need the mock reactor. Twisted provides very 
>good trial test support for creating local loopbacks between
>Twisted clients and Twisted servers. What is the issue with run and stop 
>of a reactor? To my knowledge this should not be a problem.

I'm not personally aware of one, but there were references to such problems 
in past OSAF IRC logs and commit messages, that I assumed were based on 
OSAF experience.


>Also if all the unit tests were running in the same process why would you 
>need to stop and start the reactor?

Maybe you and Heikki need to get together to see if there is actually a 
problem, then.  :)


>I have attached my recent submissions to twisted core which include a 
>pop3TestServer, a pop3Client, and a unittest illustrating how to set up 
>local client server communication.
>
>Thoughts?

As I mentioned, the last time I hacked on Twisted was a couple of years 
ago, but as recently as 2004 it was reported that Twisted doesn't support 
"simulated time" in the reactor.  If we need simulated-time tests, it might 
be worth implementing the 'installClock()/now()' methods that were 
suggested in the posting I referenced.

At the time I last worked with Twisted, I don't think twisted.trial even 
existed, and I hadn't looked at it until now.  I'll need to take a closer 
look at it if we're going to use it with run_tests, as it looks at first 
glance like twisted.trial re-implements its own incompatible version of the 
Python unittest module.

I'll take a look at it some more when I have some downtime, but my first 
impression is to worry when I see comments like "it is crappy crap, awful 
dreadful crap" (in twisted.trial.runner).  ;)  Anyway, it'll probably take 
a bit of work to integrate with the built-in unittest facility, as it 
doesn't look like it was ever designed to.  :(  Also, I've already spotted 
at least one apparent typo/bug ("moudleName" where "moduleName" was 
apparently intended).  On the plus side, however, trial is interface-based, 
so that might help a lot in getting it integrated.