public void GetAllCountries_ReturnsAllRecords() { //This test is the basic layout if you want to simulate database queries using linq. //Arrange var countries = new List <CountryIdentifiers> { new CountryIdentifiers() { CountryId = 1, CountryCode = "NZ", PhoneExtension = "64" }, new CountryIdentifiers() { CountryId = 2, CountryCode = "AU", PhoneExtension = "61" } }.AsQueryable(); var mockSet = new Mock <DbSet <CountryIdentifiers> >(); mockSet.As <IQueryable <CountryIdentifiers> >().Setup(m => m.Provider).Returns(countries.Provider); mockSet.As <IQueryable <CountryIdentifiers> >().Setup(m => m.Expression).Returns(countries.Expression); mockSet.As <IQueryable <CountryIdentifiers> >().Setup(m => m.ElementType).Returns(countries.ElementType); mockSet.As <IQueryable <CountryIdentifiers> >().Setup(m => m.GetEnumerator()).Returns(countries.GetEnumerator()); var mockContext = new Mock <StudentContext>(); mockContext.Setup(c => c.CountryIdentifiers).Returns(mockSet.Object); //Act var service = new CountryIdentifiersRepository(mockContext.Object); var results = service.GetAllCountries().ToList(); //Assert Assert.AreEqual(2, results.Count()); Assert.AreEqual("NZ", results[0].CountryCode); Assert.AreEqual("AU", results[1].CountryCode); }