Use TDD to write a method to_roman that will accept a single Integer as an argument and return a String with the value being the equivalent Roman Numeral.
Then write a to_arabic method that will accept a single String argument (a Roman Numeral) and will return its equivalent Arabic Numeral as an integer.
This is a common TDD programming challenge. This should work for positive integers from at least 1 to 2000.
You do not need to write any input/output prompts for this program.
- Write a single test that fails
- Write additional code that makes that test pass, and doesn't break prior tests
- Once this passing test is finished, do a git commit with a good commit message that describes your work.
- Repeat until complete
At the end of this exercise, you should have a git commit for every test, and each commit should light up green on Travis when I look at them.
Write a RomanNum class which will hold the above logic. It should have a to_i method that will return the number as an Arabic Numeral. If I attempt to initialize a new RomanNum with an invalid string, it should raise an appropiate error. So I should be able to do the following.
number = RomanNum.new("X")
puts number # prints "X" to the screen
number.to_i # Returns the integer 10Then extend the FixNum class with a to_roman method which will return an instance of the RomanNum class. The following code should work
number = 10
roman_number_object = number.to_roman # Returns a RomanNum object with value of "X"
puts roman_number_object # Prints "X" to the screen