Sort factory supporting array of columns and SQL-like ascending/descending sorting

keyed-object-sort.js

// Full sorting factory with SQL-like ascending and descending sort functionality
var keyedSortFactory = (function(){
    'use strict';
    
    function keyedSort(sortArray, a, b){
        var result = 0,
            index = 0,
            sortArrayLength = sortArray.length;
        
        while(result === 0 && index < sortArrayLength){
            result = sortArray[index](a, b);
        }
        
        return result
    }
    
    function keySort(key, a, b){
        var aValue = a[key],
            bValue = b[key],
            result = aValue < bValue ? -1 : 1;
            
        return aValue === bValue ? 0 : result;
    }
    
    function reverseSort(sortFunction){
        return function(a, b){
            return -1 * sortFunction(a, b);
        }
    }
    
    function sortFactory(sortString){
        var sortTokens = sortString.split(' '),
            key = sortTokens[0],
            direction = Boolean(sortTokens[1]) ? sortTokens[1].toLowerCase() : 'asc',
            sortFunction = keyedSort.bind(null, key);
        
        return direction === 'desc' ? reverseSort(sortFunction) : sortFunction;
    }
    
    function keyedSortFactory(sortStrings){
        var sortFunctions = sortStrings.map(sortFactory);
        return keyedSort.bind(null, sortFunctions);
    }

    return {
        build: keyedSortFactory
    };
})();