Our implementation of the room rate source chain. It executes the source, then runs through all the modifiers

roomRateSouceChain.js

var Promise = require('bluebird');

module.exports = function roomRateSourceChain(originalSource, modifiers) {
    return {
        getRoomRates: function () {
            var originalArguments = [].slice.call(arguments);
            return originalSource.apply(null, originalArguments)
                .then(function (roomRates) {
                    originalArguments.unshift(roomRates);
                    return Promise.reduce(modifiers, function (resultsFromPrevious, modifier) {
                        originalArguments[0] = resultsFromPrevious;
                        return modifier.apply(null, originalArguments);
                    }, roomRates);
                });
        }
    };
};