I've been thinking about test-driven development and how it could be used for developing my window manager.
I've started composing a list of tests which a bare-bones window manager must be expected to pass in order to be of any use at all: e.g. moving, resizing and closing windows - but also honouring a number of 'hints' programs can pass such as window title, resize increments, whether or not the window should be decorated.
The last one has been giving me some trouble but perhaps writing the opposite program might help. I.e. writing a bare-minimum Xlib program which sets this hint. Such a program would be part of the test-cycle but could be checked in other window managers too.
The currently checked-out copy still can't cope with complex window programs like mozilla or xmms but we'regetting there