public void Post_WithMockedModel_ShouldReturnNewId() { // Arrange var mockRepository = new Mock <IEntryRepository>(); var dbModel = new EntryModel(); var expectedValue = 4399; mockRepository .Setup(m => m.Insert(dbModel)) .Returns(expectedValue); var controller = new EntryController(mockRepository.Object); // Act var result = controller.Post(dbModel) as JsonResult; var actualValue = (int)result.Value; // Assert Assert.AreEqual(expectedValue, actualValue); }