Create a customer basket that allows a customer to add products and provides a total cost of the basket including applicable discounts.

• Buy 2 Butter and get a Bread at 50% off
• Buy 3 Milk and get the 4th milk for free

• Given the basket has 1 bread, 1 butter and 1 milk when I total the basket then the total should be £2.95
• Given the basket has 2 butter and 2 bread when I total the basket then the total should be £3.10
• Given the basket has 4 milk when I total the basket then the total should be £3.45
• Given the basket has 2 butter, 1 bread and 8 milk when I total the basket then the total should be £9.00

The solution should be in C#.

While we are looking for a solution that shows a good understanding of the SOLID principles, object�oriented programming (or functional) and that displays a working knowledge of TDD (a git repository will be appreciated!), please keep things simple- do not over-engineer anything, make sure your code is manageable and easy to follow. We are not looking for submissions that contain UIs or databases.

If you think your solution is too short, feel free to add some commentary to justify the decisions you have taken, if possible, by quoting books, blog posts or talks that have influenced you in the way you have coded.

Above all, code as if you're coding for yourself