Simple String Calculator using TDD

Before you start:

• Make sure you only test for correct inputs. There is no need to test for invalid inputs for this kata.
• Do one task at a time. The trick is to learn to work incrementally.

Why is TDD important?

TDD helps keep productivity high by narrowing focus of the developers.

Language :- Java

Tool :- Eclipse

Dependencies :- junit 3

Steps:

1. Create int Add(string numbers). This method is defined as a public and return addition of two number.
2. This method can take string as a perimeter.
3. Check for empty string. Example : " "
4. Allow the Add method to handle an unknown amount of numbers like : "1", "1,2"
5. Allow the Add method to handle an unknown amount of numbers like : I) the following input is valid : “1,2,3,4”
6. Allow the Add method to handle new lines between numbers like : I) the following input is ok: “1\n2,3” II) the following input is ok: “1\n2;3,4” III) the following input is NOT ok: “1,\n”
7. Beginning of the string will contain a separate line that looks like this: I) “//;\n1;2” should return 1+2 = 3 where the default delimiter is ‘;’ . II) The first line is optional. all existing scenarios should still be supported
8. Method also works for negative number and it will throw an exception “negatives not allowed” - and the negative that was passed.
9. add method does not contain number which is bigger than 1000 should be ignored, so adding 2 + 1001 = 2

commit

Here, every test has it's own commit which show that what kind of operation will be performed.