Trello dev challenge, for the fun of it

trello-challenge.js

var TrelloSolver = (function solver() {
    
	var ALLOWED_LETTERS = 'acdegilmnoprstuw';

	function hash(str) {
	
		var h = 7;
		
		for ( var i = 0, iLimit = str.length; i < iLimit; i++ ) {				
			h = ( h * 37 + validate(ALLOWED_LETTERS.indexOf(str[i])));		
		}	
		
		return h;
	}
	
	function validate(idx) {
	
		if (idx === -1) {
			throw new Error('The word should only contain letters in '  + ALLOWED_LETTERS);
		}	
		
		return idx;
	}

	return {
		hash : hash
	};

})();

function test() {

	var solutionMapping = {
		'leepadg': 680131659347,
		'egilmnopr' : 920662602668674,
		'a' : 259,
		'wut': 375637,
		'-':''
	};

	function assertTrue(arg1, arg2) {
		return arg1 === arg2;
	}

	for (var s in solutionMapping) {
	
		try {
			var calculated = TrelloSolver.hash(s);
			console.log('Calculated hash for ' + s + ' is ' + calculated + ' which is ' + assertTrue( calculated, solutionMapping[s] ));
		} catch (e) {
			console.log(e);
		}		
	}
}

test();