It seems to me that StyleCop is not very suitable tool for doing things like this. When writing C# code, there are many principles that could be formulated as non-parametrized conditions.
When analysing project files, almost everything turns out to be parametrized - you are running csproj checks, passing different required parameters for each project, e.g.:
- ProjectName = Project1
- VisualStudioVersion = 2008
- TargetPlatform = x86
- TargetConfiguration = Release
- DebugInfo = PdbOnly
- ProjectName = Project2
- VisualStudioVersion = 2010
- TargetPlatform = x64
- TargetConfiguration = Debug
- DebugInfo = Full
... so the purpose of such "project checker" will be mainly to check correctness of filling project properties, not some general things like identation or layout in C# code.
Of course there are some things that could be checked for every project, but often they are specific for you company or departament, e.g. in our company we are checking for so called "default configs", which have our own style. Another example
is that you may have own "references principle" that you might want to check automatically.
All that I say is just my IMHO, but I am saying this because I have a huge experience in creating such "project checker" (now it checks more than a hundred of projects). And this expirience says that it is better to have custom own-written tool
that checks all you want to check, in your own way. This tool could be also run as a part of your build process (or continious integration system).
Especially because there is really nothing difficult in parsing XML documents.