RomanNumerals

romanNumberals.js

KT.namespace("algo");

KT.algo.romanNumberals = (function () {
	"use strict";
	
	function getKeyValueObject(number, romanNumber) {
		return {
			"part": number,
			"romanNumber": romanNumber
		};
	}
	
	return function (number) {
		var map = [
			getKeyValueObject(1000,"M"),
			getKeyValueObject(900,"CM"),
			getKeyValueObject(500,"D"),
			getKeyValueObject(400,"CD"),
			getKeyValueObject(100,"C"),
			getKeyValueObject(90,"XC"),
			getKeyValueObject(50,"L"),
			getKeyValueObject(40,"XL"),
			getKeyValueObject(10, "X"),
			getKeyValueObject(9, "IX"),
			getKeyValueObject(5, "V"),
			getKeyValueObject(4, "IV"),
			getKeyValueObject(1, "I")
			];


		function getPart(value) {
			var o = new Array(Math.floor(number / value.part) + 1).join(value.romanNumber);
			number = number % value.part;
			return o;
		}

		return (isNaN(number)) ? "" : map.map(getPart).join('');
	};
})();

romanNumerals.test.js

(function () {
	
	var convert;
	
	TestCase("number to roman number", sinon.testCase({
		setUp: function () {
			convert = KT.algo.romanNumberals;
		},
		
		"test convert is a function":
		function () {
			assertFunction(convert);
		},
		
		"test less then 0":
		function () {
			assertEquals("", convert(-1));
		},
		
		"test 0":
		function () {
			assertEquals("", convert(0));
		},
		
		"test not a number":
		function () {
			assertEquals("", convert(undefined));
			assertEquals("", convert(null));
			assertEquals("", convert("foo"));
		},
		
		"test convert 1,2,3 to I, II, III":
		function () {
			assertEquals("I", convert(1));
			assertEquals("II", convert(2));
			assertEquals("III", convert(3));
			
			assertEquals("VI", convert(6));
			assertEquals("VII", convert(7));
			assertEquals("VIII", convert(8));
			
			assertEquals("X", convert(10));
			assertEquals("XI", convert(11));
			assertEquals("XII", convert(12));
			assertEquals("XIII", convert(13));
			
			assertEquals("MCMXC", convert(1990));
			assertEquals("MMVIII", convert(2008));
		},
		
		"test convert 4 to IV, 9 to IX":
		function () {
			assertEquals("IV", convert(4));
			assertEquals("IX", convert(9));
			assertEquals("XIV", convert(14));
			
		},
		
		"test convert 5 to V":
		function () {
			assertEquals("V", convert(5));
		}
		
	}));
	
})();