ghost/core/test/unit/rss/cache_spec.js

var should = require('should'),
    sinon = require('sinon'),
    rewire = require('rewire'),
    configUtils = require('../../utils/configUtils'),
    rssCache = rewire('../../../server/data/xml/rss/cache'),

    sandbox = sinon.sandbox.create();

describe('RSS: Cache', function () {
    var generateSpy, generateFeedReset;

    afterEach(function () {
        configUtils.restore();
        sandbox.restore();
        generateFeedReset();
    });

    beforeEach(function () {
        configUtils.set({url: 'http://my-ghost-blog.com'});

        generateSpy = sandbox.spy(rssCache.__get__('generateFeed'));
        generateFeedReset = rssCache.__set__('generateFeed', generateSpy);
    });

    it('should not rebuild xml for same data and url', function (done) {
        var xmlData1,
            data = {
                title: 'Test Title',
                description: 'Testing Desc',
                permalinks: '/:slug/',
                results: {posts: [], meta: {pagination: {pages: 1}}}
            };

        rssCache.getXML('/rss/', data)
            .then(function (_xmlData) {
                xmlData1 = _xmlData;

                // We should have called generateFeed
                generateSpy.callCount.should.eql(1);

                // Call RSS again to check that we didn't rebuild
                return rssCache.getXML('/rss/', data);
            })
            .then(function (xmlData2) {
                // Assertions

                // We should not have called generateFeed again
                generateSpy.callCount.should.eql(1);

                // The data should be identical, no changing lastBuildDate
                xmlData1.should.equal(xmlData2);

                done();
            })
            .catch(done);
    });
});