fix tests

Author: dplewis

src/__tests__/Storage-test.js

@@ -207,11 +207,14 @@ describe('IndexDB StorageController', () => {
   });
 
   it('handle indexedDB is not accessible', async () => {
-    jest.spyOn(idbKeyVal, 'createStore')
-      .mockImplementationOnce(() => { throw new Error('Protected'); });
-    const dbController = require('../IndexedDBStorageController');
-    expect(idbKeyVal.createStore).toHaveBeenCalled();
-    expect(dbController).toBeUndefined();
+    jest.isolateModules(() => {
+      global.indexedDB = mockIndexedDB;
+      jest.spyOn(idbKeyVal, 'createStore')
+        .mockImplementationOnce(() => { throw new Error('Protected'); });
+      const dbController = require('../IndexedDBStorageController');
+      expect(dbController).toBeUndefined();
+      expect(idbKeyVal.createStore).toHaveBeenCalled();
+    });
   });
 });