JSFiddle - React, Tailwind, and code Playground

JavaScript

function checkSource(src) {
    var def = $.Deferred(),
        res = ['620x350', '180x60', '180x60'];

    (function s(i) {
        $('<img />', {src : (src + '_' + res[i] + '.jpg')}).on({
            load: function() {
                def.resolve(this.src);
            },
            error: function() {
                if (i != res.length-1) {
                    s(++i);
                }else{
                    def.resolve(this.src);
                }
            }
        });
    }(0));
    return def.promise();
};


checkSource('banner').done(function(file) {
    console.log(file)
});