Re: XML and unit testing

["Thomas B. Passin" <tpassin@home.com>]

I'd recommend you look at Martin Fowler's excellent book, "Refactoring -
Improving the Design of Existing Code" (Addison-Wesley).  He has a lot of
good material on unit testing, including making objects self-testing by
including test() methods.  He does talk about using JUnit.

Basically, you can make a piece of code self-testing, or you can write test
wrappers to exercise it.  Either way, you want to make each test
self-checking, so you don't have to pore over printouts (which isn't that
reliable anyway).  That means you have to come up with a canonical, correct
result for each test that can in some way be checked automatically.  This is
more important, I would say, than which specific test harness you use and
exactly how it works.

There is a Python PyUnit, too.  I would imagine it would work with Jython as
well (don't know that for a fact, though).  That might make it quicker to
set up a test harness.

That DeltaXML tool (http://www.deltaxml.com) that was just announced on the
list might be useful for comparing two pieces of xml.  You could run it from
the command line or from java.

Cheers,

Tom P

[Simon St.Laurent]

> I've been considering a unit testing approach for my Regular
> Fragmentations processor [1], trying to figure out what kinds of unit
> testing make sense for a SAX filter [2].  I've looked at things like
> JUnit [3], JXUnit [4], XSLTUnit[5], and XMLUnit[6], and I think I'm now
> more confused than when I started.
>
> In testing a filter, I need to be able to test component pieces, some of
> which are plain old objects and some of which are representations of
> those objects as SAX events and/or XML.  I've had a number of cases
> involving shallow copying (finally fixed) where the objects looked great
> at the time of their creation but morphed by the time they reached the
> XML output, so I really need to be able to test these things in a
> variety of situations.
>
> So far, I've been using a set of test cases and my own eyeballs.  It's
> worked pretty well as far as figuring out high-level pass/fail, but does
> very little to help me track down where the pass/fail came from.
>
> I doubt I'm the only person dealing with these kinds of issues on
> xml-dev, but I still wonder if anyone's really explored how unit testing
> and XML fit together.  Validation is something that comes naturally to
> XML, but it's a different kind of testing than the finer-grained object
> unit testing approach I'm looking for.
>