I need help with tests

[Manuel Martín]

Hi
I'm trying to modify \tests\strings\unicode.cpp in order to
make a patch for the new function wxCSConv::IsOk().

First I try to compile test without any modification. Later on I will 
modify the file and compile it again to test it.

But gcc shows errors:
In file included from testprec.h:2,
                  from dummy.cpp:28:
./../include/wx/cppunit.h:47:52: error: 
cppunit/extensions/TestFactoryRegistry.h
: No such file or directory

and more like this.

So I discover I need something called cppunit.
What is this and how do I use it?
Can someone explain me a bit of how tests code is written?
Digging into files is too slow and a bit of help would make me write a 
new test more quickly.

TIA
Manolo