Coveo JavaScript Search Framework extension to add Tab count

CoveoTabCount.js

Coveo.activateTabCount = (function(searchInterfaceElement, onTabCountResolved) {
    var searchInterfaceDom = Coveo.$$(searchInterfaceElement);
    var tabGroupBys = [];
    searchInterfaceDom.on(Coveo.QueryEvents.doneBuildingQuery, function(event, args) {
        tabGroupBys = [];
        var allTabs = searchInterfaceDom.findAll(".CoveoTab").map(function(tabDom) {
            return Coveo.get(tabDom, Coveo.Tab);
        });
        var allTabsExpressions = allTabs.map(function(tab) {
            return tab.options.expression;
        });
        allTabs.forEach(function(tab) {
            var groupByIndex = args.queryBuilder.groupByRequests.length;

            var tabExpression = new Coveo.ExpressionBuilder();
            tabExpression.add(tab.options.expression || "@uri");

            var expressionsWithoutTabExpression = args.queryBuilder.advancedExpression.parts.filter(function(part) { 
                return allTabsExpressions.indexOf(part) === -1; 
            });
            var advancedExpression = new Coveo.ExpressionBuilder();
            tabExpression.add(expressionsWithoutTabExpression.join(" "));

            var tabQuery = Coveo.ExpressionBuilder.merge(args.queryBuilder.expression, advancedExpression, args.queryBuilder.constantExpression, tabExpression).build();
            var tabRequest = {
                field: '@syssource',
                maximumNumberOfValues: 16,
                sortCriteria: "nosort",
                injectionDepth: 1000,
                completeFacetWithStandardValues: true,
                queryOverride: tabQuery
            };
            args.queryBuilder.groupByRequests.push(tabRequest);
            tabGroupBys.push({
                index: groupByIndex,
                element: tab.element,
                originalText: tab.options.caption
            });
        });
    });
    searchInterfaceDom.on(Coveo.QueryEvents.querySuccess, function(event, args) {
        tabGroupBys.forEach(function(groupBy) {
            onTabCountResolved({
                count: countTotalForGroupByResult(args.results.groupByResults[groupBy.index]),
                element: groupBy.element,
                originalText: groupBy.originalText
            });
        });
    });

    function countTotalForGroupByResult(groupByResult) {
        var totalCount = 0;
        for (var i = 0; i < groupByResult.values.length; i++) {
            totalCount += groupByResult.values[i].numberOfResults;
        }
        return totalCount;
    }
});