Has anyone created any cool rules for FxCop/StyleCop?

Question

I'm just looking for some inspiration. Especially in the area of performance and security, naming conventions are important but not as 'cool' ;)

Even if your rule was only applicable to your domain/project but demonstrates how powerful a rule can be, please let me know.

I work with C#, but I'm interested in rules for any language.

Answer 1

In my experience, the developers that have started out creating custom rule sets for FxCop, usually give up after pulling out much hair. It seems like a great idea, but the pain is just not worth the effort.

Answer 2

An alternative to the mess of writing FxCop custom rules would be to use NDepend and its Code Query language (CQL). CQL is dedicated to write code quality rules that can be verified live in Visual Studio, or that can be verified during build process and reported in a HTML report. Here are a few samples of CQL rules (designed to be highly customizable):

Code refactored recently should be 100% covered by test:

WARN IF Count > 0 IN SELECT METHODS WHERE CodeWasChanged AND PercentageCoverage < 100

Complex methods should be commented:

WARN IF Count > 0 IN SELECT METHODS WHERE CyclomaticComplexity > 15 AND PercentageComment < 10

I don’t want that my User Interface layer to depend directly on the DataBase layer:

WARN IF Count > 0 IN SELECT NAMESPACES WHERE IsDirectlyUsing "DataLayer" AND NameIs "UILayer"

Static fields should not be named m_XXX (Custom naming conventions):

WARN IF Count > 0 IN SELECT FIELDS WHERE NameLike "^m_" AND IsStatic

Methods out of MyAssembly and MyAssembly2 should not have more than 30 lines of code:

WARN IF Count > 0 IN SELECT METHODS OUT OF ASSEMBLIES "MyAssembly1", "MyAssembly2" WHERE NbLinesOfCode > 30

Public methods should not be removed to avoid API breaking changes:

WARN IF Count > 0 IN SELECT METHODS WHERE IsPublic AND IsInOlderBuild AND WasRemoved

Types tagged with the attribute MyNamespace.FullCoveredAttribute must be thoroughly covered by tests:

WARN IF Count > 0 IN SELECT TYPES WHERE HasAttribute "MyNamespace.FullCoveredAttribute" AND PercentageCoverage < 100