As an end-user, I want the calculator to accept a list of numbers with any length, so that I may calculate the sum of a collection of numbers.
- Calculator can accept a list of n numbers in a single string format
- Calculator correctly sums the string of numbers
- Numbers are separated by a comma
"1,2,3,5"=> 11
- Start with the simplest test case of an empty string and move to 1 and 2 numbers
- Solve things as simply as possible so that you force yourself to write tests you did not think about
- Refactor after each passing test