Question

I’m trying to get rid of all DateTime.Now method calls and replace them with my own GetNow() method, which may sometimes return a fixed date for testing purposes.

How can I enforce that no one adds a DateTime.Now call in the future? Can I use NDepend or StyleCop to check this on my continuous integration server?

Answer 1

With NDepend it is very easy to write this rule:

// <Name>Forbid DateTime.Now, use xxx.GetNow() instead</Name>
WARN IF Count > 0 IN 
SELECT METHODS WHERE 
IsDirectlyUsing "OPTIONAL:System.DateTime.get_Now()"

Notice:

• The prefix WARN IF Count > 0 IN that transforms the CQL query into a rule
• The way the property is referenced through the string System.DateTime.get_Now()
• The prefix OPTIONAL that means “Don’t emit a compilation error if the property get_Now is not found”. This makes sense since if your code doesn’t use anymore get_Now(), it is not anymore referenced from NDepend analysis.

Also, to generate the original query…

SELECT METHODS WHERE 
IsDirectlyUsing "OPTIONAL:System.DateTime.get_Now()"

…just right-click DateTime.get_Now() and choose Select methods … that are directly using me