JS: GA tracker with support for Modernizr tests

ga-tracker.js

/**
 * A Google Analytics event tracking proxy.
 *
 * This lobal allows us to do tests for the instantiation of _gaq 
 * and also allows us easier debugging in a test environment.
 *
 * Hat-tip to @stugoo for most the self-invoked function features!
 * 
 */
window.track  = function (args) {
    args = args || {};

    // defaults
    var category = args.category || '',
        action = args.action || '',
        label = args.label || '',
        value = args.value || null;

    if (_gaq) {
        _gaq.push(['_trackEvent', category, action, label, value]);
    }
};


(function (Modernizr) {

	// set what you want to track here
    var trackpasses = true,
		trackfails = true,


		/**
		 * Staging - check on our requirements of what to track
		 */
		trackFeature = function (results) {

	        if (trackpasses) {
				SDM.track({ category: 'modernizr', action: 'passes', label: results.passed });
			}

			if (trackfails) {
				SDM.track({ category: 'modernizr', action: 'fails', label: results.failed });
			}

	    },


	    /**
	     * Run through all the Modernizr tests
	     */
	    log = function() {
	    	
	        var tests = { passed: [], failed: [] };

	        // avoid functions, arrays and other objects
	        for (test in Modernizr) {
	            if (typeof Modernizr[test] === 'function' || typeof Modernizr[test] === 'array' || typeof Modernizr[test] === 'object') continue;
	            if (Modernizr[test]) {
	            	tests.passed.push(test);
	            } else {
	            	tests.failed.push(test);
	            }
	        }

	        // commas will break the GA _trackEvent method
	        tests.passed = tests.passed.join('|');
	        tests.failed = tests.failed.join('|');
	        
	        trackFeature(tests);
	    };

    if (trackpasses || trackfails)  return log();

})(Modernizr);