public void GetExpenseCategories_ShouldReturnIEnumerableOfExpenseCategory_WhenItIsCalled()
        {
            // Arrange
            var expenseService = new ExpenseService(unitOfWorkMock.Object, expenseRepoMock.Object, expenseCategoryRepoMock.Object, expenseFactoryMock.Object, commentFactoryMock.Object);

            // Act
            var result = expenseService.GetExpenseCategories();

            // Assert
            Assert.IsInstanceOf <IEnumerable <ExpenseCategory> >(result);
        }
        public void ExpenseCategoryRepo_ShouldCallGetAllOnce_WhenGetExpenseCategoriesIsCalled()
        {
            // Arrange
            var expenseService = new ExpenseService(unitOfWorkMock.Object, expenseRepoMock.Object, expenseCategoryRepoMock.Object, expenseFactoryMock.Object, commentFactoryMock.Object);

            // Act
            expenseService.GetExpenseCategories();

            // Assert
            this.expenseCategoryRepoMock.Verify(x => x.GetAll(), Times.Once);
        }