Write a program and associated unit tests that can price a basket of goods taking into account some special offers.
The goods that can be purchased, together with their normal prices are:
- Soup – 65p per tin
- Bread – 80p per loaf
- Milk – £1.30 per bottle
- Apples – £1.00 per bag
Current special offers:
- Apples have a 10% discount off their normal price this week
- Buy 2 tins of soup and get a loaf of bread for half price
The program should accept a list of items in the basket and output the subtotal, the special offer discounts and the final price.
Input should be via the command line in the form node index.js item1 item2 item3 ...
For example:
node index.js Apples Bread Milk
Output should be to the console, for example:
Subtotal: £3.10
Apples 10% off: -10p
Total: £3.00
If no special offers are applicable the code should output:
Subtotal: £1.30
(No offers available)
Total price: £1.30
The code and design should meet these requirements, but be sufficiently flexible to allow future changes to the product list and/or discounts applied.
The code should be well structured, commented, have error handling and be tested.