The Diamond Kata is a TDD exercise. We have already provided a small collection of unit tests that correctly assert the expected behaviour of the application.
The task is to get all the tests passing and have the code generate the expected string for a given single character input.
This exercices asks for a 'odd number generator', where each number is the next row of a pyramid.
I tried a simple resolution where the result for the first row is fixed ('A\n') and we calculates each iteration based on index of the letter in the range 'B'..x, where 'x' is the given input.
The easy part of the challenge is once I resolved the pyramid ('A'..'J', by example) the second part is just a mirror of the result without the last element.
input:
A
output:
A
input:
B
output:
_A_
B_B
_A_
input:
E
output:
____A____
___B_B___
__C___C__
_D_____D_
E_______E
_D_____D_
__C___C__
___B_B___
____A____
To run the tests you need to do the following:
- Ensure you are using a compatible ruby version (>= 2.3.0)
bundle installbin/rspec