Check for onload event in async scripts

asyncOnLoad.js

(function(d) {

    /**
     * asyncOnLoad - Initilize all functions that depend on document.ready
     * Since we load script async we must check if document already loaded or listen for DOMContentLoaded event.
     * @param  {Function} cb - callback function - put all stuff that must run here
     */
    var asyncOnLoad = function(cb) {
        // cut the mustard
        if ('addEventListener' in d) {
            if (d.readyState !== "loading") {
                cb();
            } else {
                 d.addEventListener('DOMContentLoaded', cb);
            }
        } else {
            console.log('browser not supported!');
        }
    
    };

    // commonjs
    if (typeof module !== 'undefined') {
        module.exports = asyncOnLoad;
    } else {
        window.asyncOnLoad = asyncOnLoad;
    }

})(document);

function test(str) {
    console.log(str);
}

// Init stuff
asyncOnLoad(function() {
    test('hello world');
});