Adding Caching Adapter, allows caching of _Role and _User queries (fixes #168) (#1664)

* Adding Caching Adapter, allows caching of _Role and _User queries.

spec/CacheController.spec.js

@@ -0,0 +1,74 @@
+var CacheController = require('../src/Controllers/CacheController.js').default;
+
+describe('CacheController', function() {
+  var FakeCacheAdapter;
+  var FakeAppID = 'foo';
+  var KEY = 'hello';
+
+  beforeEach(() => {
+    FakeCacheAdapter = {
+      get: () => Promise.resolve(null),
+      put: jasmine.createSpy('put'),
+      del: jasmine.createSpy('del'),
+      clear: jasmine.createSpy('clear')
+    }
+
+    spyOn(FakeCacheAdapter, 'get').and.callThrough();
+  });
+
+
+  it('should expose role and user caches', (done) => {
+    var cache = new CacheController(FakeCacheAdapter, FakeAppID);
+
+    expect(cache.role).not.toEqual(null);
+    expect(cache.role.get).not.toEqual(null);
+    expect(cache.user).not.toEqual(null);
+    expect(cache.user.get).not.toEqual(null);
+
+    done();
+  });
+
+
+  ['role', 'user'].forEach((cacheName) => {
+    it('should prefix ' + cacheName + ' cache', () => {
+      var cache = new CacheController(FakeCacheAdapter, FakeAppID)[cacheName];
+
+      cache.put(KEY, 'world');
+      var firstPut = FakeCacheAdapter.put.calls.first();
+      expect(firstPut.args[0]).toEqual([FakeAppID, cacheName, KEY].join(':'));
+
+      cache.get(KEY);
+      var firstGet = FakeCacheAdapter.get.calls.first();
+      expect(firstGet.args[0]).toEqual([FakeAppID, cacheName, KEY].join(':'));
+
+      cache.del(KEY);
+      var firstDel = FakeCacheAdapter.del.calls.first();
+      expect(firstDel.args[0]).toEqual([FakeAppID, cacheName, KEY].join(':'));
+    });
+  });
+
+  it('should clear the entire cache', () => {
+    var cache = new CacheController(FakeCacheAdapter, FakeAppID);
+
+    cache.clear();
+    expect(FakeCacheAdapter.clear.calls.count()).toEqual(1);
+
+    cache.user.clear();
+    expect(FakeCacheAdapter.clear.calls.count()).toEqual(2);
+
+    cache.role.clear();
+    expect(FakeCacheAdapter.clear.calls.count()).toEqual(3);
+  });
+
+  it('should handle cache rejections', (done) => {
+
+      FakeCacheAdapter.get = () => Promise.reject();
+
+      var cache = new CacheController(FakeCacheAdapter, FakeAppID);
+
+      cache.get('foo').then(done, () => {
+          fail('Promise should not be rejected.');
+      });
+  });
+
+});