RE: [Cppunit-devel] Parameterizing tests by using XML

[Michel A. <Arm...@si...>]

> -----Original Message-----
> From: Robert Wenner [mailto:ro...@po...]
> Sent: Freitag, 19. Juli 2002 09:01
> To: Michel Armin; cpp...@li...
> Subject: Re: [Cppunit-devel] Parameterizing tests by using XML
> 
> 
> Hi,
> 
> On Friday 19 July 2002 08:36, Michel Armin wrote:
> > Hi all.
> >
> > Actually I was thinking about a little bit different solution here.
> > It differs mainly in two points:
> >
> > 1. the framework should be responsible for parsing the xml file and
> > invoke the test with a particular set of parameters (as opposed to
> > let each of the test cases perform the parsing)
> >
> > 2. the DTD of the xml file is a less sophisticated
> 
> These are _very_ important points -- you would not want to need test 
> cases for your test cases, right?
> 
> I still see two big drawbacks on using a XML driven test.
> 
> First it drops the advantage of having the tests written in the same 
> language as the code under test. Developers have to learn another new 
> language / syntax / semantics and can not focus on their real work. 
> Even though XML looks easy, it has some pitfalls you will most likely 
> uncover and which will cost really lots of time, nerves, and sanity.

That's of course true, but I do not want to get rid of the current flavor of
programming tests; I just want to add a new possibility to write tests.

> Second I don't think the XML overhead justifies the results. How many 
> tests do you have that run the same way that you just need to 
> exchange 
> the input and output values? (And how many of those use primitive 
> inputs and outputs?) If I ever have to write more than three 
> tests for 
> the same method, I think hard about abetter design, usually 
> the method 
> has just too much responsibilities.

Actually almost all of my tests would benifit from such a parameterized
testing approach. (Most of our code is concerned with manipulating images.
Of course, we support a number of different types of images. Our functions
should be able to deal with all of these types of images in a transparent
way. If I have a possibility to parameterize the type of the image used for
a test, I could greatly improve the test coverage.)

Armin.