Testing database logic

Hi,

I want to test some database logic. I've written a test which calls a class which simply logs the current date:

[Fact]
public async Task LogCurrentDate_DbIsEmptyTest()
{
	var emptyData = new List<DateTimeLog>
	{
	};

	var mockDateTimeSet = new Mock<DbSet<DateTimeLog>>();
	mockDateTimeSet.As<IQueryable<DateTimeLog>>().Setup(m => m.Provider).Returns(emptyData.AsQueryable().Provider);
	mockDateTimeSet.As<IQueryable<DateTimeLog>>().Setup(m => m.Expression).Returns(emptyData.AsQueryable().Expression);
	mockDateTimeSet.As<IQueryable<DateTimeLog>>().Setup(m => m.ElementType).Returns(emptyData.AsQueryable().ElementType);
	mockDateTimeSet.As<IQueryable<DateTimeLog>>().Setup(m => m.GetEnumerator()).Returns(emptyData.GetEnumerator());
	mockDateTimeSet.As<IListSource>().Setup(m => m.GetList()).Returns((List<DateTimeLog>)emptyData);

	var mockDbContext = new Mock<QlcContext>();
	mockDbContext.Setup(repo => repo.DateTimeLog).Returns(mockDateTimeSet.Object);

	DateTimeLogger dateTimeLogger = new DateTimeLogger(mockDbContext.Object);
	await dateTimeLogger.LogCurrentDate();

	var entries = mockDateTimeSet.Object.ToList(); // List is still empty!
	Assert.Equal(DateTime.UtcNow.Date, entries[0].DateTimeActivityLog); // Test fails!
}

I'm providing a mockup and I expect, that the emptyData mock gets filled by thedateTimeLogger instance, but when I test the result at the end, the list is still empty.

My DateTimeLogger class uses code like:

await _dbContext.DateTimeLog.AddAsync(newLogEntry);
await _dbContext.SaveChangesAsync();

Where's the problem?

Thanks in advance!
Stefano