Sum Trello Points

trello-sum-points.js

/* 
 * Reads trello card titles of the format "My Trello card (4)" where the number in parentheses 
 * is some number of sprint points. It sums up the points in list, and adds it to the list header.
 * 
 * To use it as a bookmarklet on Trello, make a new bookmark, and set the bookmark URL to the 
 * below javascript, prefixed by "javascript:"
 * Example Bookmark:
 *   Name: Sum Trello Points
 *   URL: javascript:(function() {var pointsIn...
 */
(function() {
    var pointsInTitleRegex = /.*\((\d)\)$/;
    $("#board .list").each(function(_, list) {
        var points = sumList(list);
        $(".list-header-name", list).append(" (" + points + ")");
    });
    function sumList(list) {
        return $(".list-card-title", list).toArray()
            .map(function(elem) {
                return extractPoints(elem.textContent);
            })
            .reduce(function(accumulate, current) {
                return accumulate + current;
            }, 0);
    }
    function extractPoints(cardTitle) {
        var match = cardTitle.match(pointsInTitleRegex);
        return match && match.length === 2 ? parseInt(match[1], 10) : 0;
    }
})();