Challenge

Create a program with twenty commits. Put an error in one of the early commits that won't break the working program (so that it can be hidden). Use bisect to find the error.

The first step is to create a program with 20 commits. I decided to create a program that holds information about a book:

namespace BisectTest
{
    public class Book
    {
        public string Author { get; set; }
        public string BookName { get; set; }
        public double Price { get; set; }
        public double DiscountPrice { get; set; }
        internal double WholeSalePrice { get; set; }
        internal double DiscontinuedPrice { get; set; }
        public void ComputePrice()
        {
            Price = WholeSalePrice + (WholeSalePrice * .5);         
        }
        public void ComputeDiscountPrice()
        {
            DiscountPrice = Price * 2;
        }
        public void ComputeDiscontinued()
        {
            DiscontinuedPrice = DiscontinuedPrice * 0.8;
...