Unable to Mock when using Entity Functions

[John]

I have been attempting to learn how we can mock out calls to entity framework in our project. I ran into this problem where we are using EntityFunctions.TruncateTime. The error says: this function can only be invoked from linq to entities. If this should be supported help on what i'm doing wrong, if its not then i guess we are out of luck for those scenarios.

from audit in _context.Audits
where audit.DTS < EntityFunctions.TruncateTime(mydate)
select audit

var fakeEntities = Mock.Create<SomeDBEntities>();
var audits = GetAudits();
Mock.Arrange(() => fakeEntities.Audits).ReturnsCollection(audits);
var target = new ReportRepository(fakeEntities);

var result = target.test(DateTime.Now);

Assert.AreEqual(2, result.Count());

Thanks
John

[Ricky]

Hi John,

Thanks again for reporting the problem. It could be the issue that
EntityFunctions.TruncateTime could not be used in this context but will investigate more on that and therefore creating an PITS entry.

You can further check the progress of the task here:
http://www.telerik.com/support/pits.aspx#/public/justmock/9290

Kind Regards,
Mehfuz
the Telerik team

[Motheo]

Hi Guys,

 

Didi you get solution to the above problem.

[Stefan]

Hi Motheo,

The EntityFunctions.TruncateTime method doesn't actually do anything - it just gets translated into the equivalent DB function when the LINQ query is translated to SQL.

You can arrange the function to implement the semantical behavior of that DB call.

Mock.Arrange(() => EntityFunctions.TruncateTime(Arg.IsAny<DateTime?>())).Returns((DateTime? dt) => dt != null ? dt.Value.Date : null);

Regards,
Stefan
Telerik