Sales Taxes
Basic sales tax is applicable at a rate of 10% on all goods, except books, food, and medical products that are exempt. Import duty is an additional sales tax applicable on all imported goods at a rate of 5%, with no exemptions.
When I purchase items I receive a receipt which lists the name of all the items and their price (including tax), finishing with the total cost of the items, and the total amounts of sales taxes paid. The rounding rules for sales tax are that for a tax rate of n%, a shelf price of p contains (np/100 rounded up to the nearest 0.05) amount of sales tax.
Write an application that prints out the receipt details for these shopping baskets...
Project Structure
The structure is simple. The model is just the class Item which contains immutable data representing a product. The class TaxCalculator contains the domain of the program. It has two main methods, one to add items to the cart and other to get the receipt as a String. Both classes have their tests associated.
To build the project and run the tests use Gradle.
Notes
- Use of BigDecimal for computations for the precision that it offers and to avoid rounding errors.
- Sales taxes are composed by Basic sales taxes and Import taxes. Therefore an imported item should have applied both if applicable.
- Round rule is applied separately to each tax increment.
- The data source is out of the scope and it is the tests that use files to load the test data into the program.
Input files for testing:
Input files have LF Unix type Line Separators (\n). Each line of the input files for testing are in the format:
(\d+) (.*) at (\d+\.\d{2})\n
- Where the first group in the regular expression is the quantity of the product.
- Second group is the description which it doesn't contain the substring " at " inside.
- Third group is the single product price. More details here