function makePromisesTraceable() {
    var NativePromise = window.Promise;
    window.promiseRegistry = [];
    window.Promise = function(cb) {
        var state = {};
        var p = new NativePromise(function(resolve, reject) {
            var res = function(v) { state.status = 'resolved'; state.value = v; resolve(v); };
            var rej = function(v) { state.status = 'rejected'; state.value = v; reject(v); };
            return cb(res, rej);
        });
        p.callback = cb;
        p.state = state;
        window.promiseRegistry.push(p);
        return p;
    };

    Promise.resolve = function(item) {
        return new Promise(function(resolve) { resolve(item); });
    };

    Promise.all = function(arr) {
        return new Promise(function(resolve) {
            var results = [];
            if (arr.length === 0) resolve(results);

            var pendingCount = arr.length;
            arr.forEach(function(val, index) {
                Promise.resolve(val).then(function(res) {
                    results[index] = res;
                    pendingCount--;
                    if (pendingCount === 0) resolve(results);
                });
            });
        });
    };
}