How to mock the DateTime.Now method?

Posted on 2014-09-11
Last Modified: 2014-09-12
I am using TDD and can't get my mocking of the DateTime.Now method working.  I found this post on the web and am trying to implement the solution:

Here is my relevant code:
    public static class SystemTime
        public static Func<DateTime> Now = () => DateTime.Now;

    public partial class RequestProcessLogic
        IReferralsModelContainerRepository _repository;
        EmployeeProfileRecord _emprec;

        public RequestProcessLogic() : this(new EF_ReferralsModelContainerRepository(), new EmployeeProfileRecord())
        { }
        public RequestProcessLogic(IReferralsModelContainerRepository repository, EmployeeProfileRecord emprec=null)
            _repository = repository;
            _emprec = emprec;
        public virtual NewReferralRequestModel PopulateNewRequestModel(Int32 referraltypeid, string uniquekeyvalues, Int32 employeeprofileid)
            // Get ReferralType informataion for NewRequestMoel
            REF_ReferralType rt = _repository.GetReferralType(referraltypeid);

            // Return null if no data found
            if (rt == null)
                return null;

            // Parse uniquekeyvalues
            string[] keyvalues = uniquekeyvalues.Split(',');

            // Populate the NewRequestModel
            NewReferralRequestModel model = new NewReferralRequestModel();
            model.ReferralTypeID = rt.ReferralTypeID;
            model.ReferralTypeName = rt.ReferralTypeName;
            model.ReferralGroupName = rt.REF_ReferralGroup.ReferralGroupName;
            model.ReferralTypeMoreInfoLink = rt.ReferralTypeMoreInfoLink;
            model.ReferralTypeGeneralGuidelines = rt.ReferralTypeGeneralGuidelines;
            model.ReferralSynopsis = null;
            model.ReferralComments = null;
            model.ReferralPriority = PriorityType.Normal;
            model.ReferralRequesterProfileID = employeeprofileid;
            model.ReferralEstimatedCompletionDate = CalculateSLACompletionDate(DateTime.Now, rt.ReferralTypeSLA);
            model.ReferralTypeSLA = rt.ReferralTypeSLA;
            model.ReferralTypeRoute = rt.ReferralTypeRoute;
            model.ReferralTypeRequiresApproval = rt.ReferralTypeRequiresApproval;

            return model;

        public virtual DateTime CalculateSLACompletionDate(DateTime datetocalculatefrom, int sla)
            // Add SLA calculation code
            return datetocalculatefrom;

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Unit Testing Code
        public void PopulateNewRequestModel_Returns_Model_If_ReferralTypeID_Is_Found_In_ReferralType_Table()
            // Arrange
            InMemoryReferralsModelContainterRepository repository = imr.PopulateInMemoryRepository();
            // Mock the EmployeeProfileRecordClass
            var mockEmployeeProfileRecord = new Mock<EmployeeProfileRecord>(epimr);
                .Setup(epr => epr.GetEmployeeFirstNameLastName(5810))
            SystemTime.Now = () => Convert.ToDateTime("8/18/2014 12:00 PM"); 
            RequestProcessLogic sut = new RequestProcessLogic(repository, mockEmployeeProfileRecord.Object);

            // Act
            NewReferralRequestModel result = sut.PopulateNewRequestModel(10, "DRC Policy, 12345678, 2/14/14", 5810);

            // Assert
            Assert.AreEqual(10, result.ReferralTypeID);
            Assert.AreEqual("URS Test Referral", result.ReferralTypeName);
            Assert.AreEqual("Testing", result.ReferralGroupName);
            Assert.AreEqual(null, result.ReferralTypeMoreInfoLink);
            Assert.AreEqual("Referral Guidelines", result.ReferralTypeGeneralGuidelines);
            Assert.AreEqual(PriorityType.Normal, result.ReferralPriority);
            Assert.AreEqual(5810, result.ReferralRequesterProfileID);
            Assert.AreEqual(Convert.ToDateTime("8/18/2014 12:00 PM"), result.ReferralEstimatedCompletionDate);
            Assert.AreEqual(2880, result.ReferralTypeSLA);
            Assert.AreEqual("RequestProcess", result.ReferralTypeRoute);
            Assert.AreEqual(true, result.ReferralTypeRequiresApproval);

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The call to DateTIme.Now returns the current date/time.  How do I set this up so when testing I can set the datetime to be returned?  Any help is greatly appreciated!
Question by:dyarosh
  • 3
  • 3
LVL 75

Expert Comment

by:käµfm³d 👽
ID: 40318089
How do I set this up so when testing I can set the datetime to be returned?
I'm confused:  Isn't that exactly what you are doing in line 11 of the 2nd snippet?

Author Comment

ID: 40319103
That is what I am trying to do but when I make the call to DateTime.Now it returns the real time not the time I set.
LVL 75

Expert Comment

by:käµfm³d 👽
ID: 40319184
Where are you actually using this SystemTime class? I see where you assign to it, but I don't see anywhere else that you refer to it.
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Author Comment

ID: 40319269
I make a call to DateTime.Now in the PopulateNewRequestModel method:

model.ReferralEstimatedCompletionDate = CalculateSLACompletionDate(DateTime.Now, rt.ReferralTypeSLA);

I tried replacing DateTime.Now with SystemTime.Now but then I get the following Compiler error and I can't figure out how to get rid of it.

Error      2      The best overloaded method match for 'UniversalReferrals.BusinessLogic.RequestProcessLogic.CalculateSLACompletionDate(System.DateTime, int)' has some invalid arguments      
Error      3      Argument 1: cannot convert from 'System.Func<System.DateTime>' to 'System.DateTime'
LVL 75

Accepted Solution

käµfm³d   👽 earned 500 total points
ID: 40319355
Invoke it:


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Author Closing Comment

ID: 40319491
Figures it would be something stupid that I wasn't doing.  Thank you so much.  That solved my problem!

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