CString and Unit Tests

Right at the head of the link errors was the CString class and most of it's methods. Early on in the port I copied the class declaration from MFC, commented out almost all of the methods and then uncommented the ones that as I got compile errors. It is surprising just how few of the class methods are used. At the time I knew that I wanted to implement it as a CFString so I added constructors and accessors so that I could freely convert from CFString.

Implementing the CString methods was fairly straightforward - so much so that I paused before writing any UnitTests, not wanting to waste time.


I retire some hours later with renewed belief in writing unit tests. Many of the tests worked straight off the bat - but I found serious problems in my implementation of CString::Format that would have bitten me later and would have taken longer to fix at a later date. Also using the accesors to get the underlying CFString it has been possible to check that the owner counts of the CFString are being handled correctly - I am using boost::intrusive_pointer for the actual management - but the copy constructor and assignment operations should share the underlying pointers. Unit test identified some problems here.

There is an interesting post about unit testing by Will Shipley (Delicious Monster). As well as some good info about unit testing by Chris Hanson (where I found the link to the Will Shipely post).