UnitTesting with DateTime.Now

Today I needed to unit test a component which uses System.DateTime.Now (C# .NET) ...

The good answer:this actually works using System.Fakes (sorry, no idea in which edition, but in ultimate it works perfectly). In the past microsoft seemed to use "moles" (see: http://research.microsoft.com/en-us/projects/moles/ ) instead of "fakes".

Using fakes:

• Create a Unit-Test Project
• Select References
• Right-Click on "add fakes assembly" 
• this adds ref to "...Fakes.dll"
• Fakes Folder with xml stuff
• now you enabled fakes for system (most of the time mscorlib will be faked too by VS)... 
• start to use it

Code:

1 2 3 4 5 6 7 8 9 10 11 12 13

[TestMethod] public void CheckCurrentDate_ResultFixed2012() { // Arrange using (ShimsContext.Create()) { // Act System.Fakes.ShimDateTime.NowGet = () => new DateTime(2012, 12, 31); // Assert Assert.AreEqual(2012, DateTime.Now.Year); } }

Kind regards, Daniel