diff --git a/spec/MongoStorageAdapter.spec.js b/spec/MongoStorageAdapter.spec.js
new file mode 100644
index 00000000..785772b4
--- /dev/null
+++ b/spec/MongoStorageAdapter.spec.js
@@ -0,0 +1,37 @@
+'use strict';
+
+const MongoStorageAdapter = require('../src/Adapters/Storage/Mongo/MongoStorageAdapter');
+const MongoClient = require('mongodb').MongoClient;
+
+describe('MongoStorageAdapter', () => {
+  it('auto-escapes symbols in auth information', () => {
+    spyOn(MongoClient, 'connect').and.returnValue(Promise.resolve(null));
+    new MongoStorageAdapter('mongodb://user!with@+ symbols:password!with@+ symbols@localhost:1234/parse', {})
+      .connect();
+    expect(MongoClient.connect).toHaveBeenCalledWith(
+      'mongodb://user!with%40%2B%20symbols:password!with%40%2B%20symbols@localhost:1234/parse',
+      jasmine.any(Object)
+    );
+  });
+
+  it("doesn't double escape already URI-encoded information", () => {
+    spyOn(MongoClient, 'connect').and.returnValue(Promise.resolve(null));
+    new MongoStorageAdapter('mongodb://user!with%40%2B%20symbols:password!with%40%2B%20symbols@localhost:1234/parse', {})
+      .connect();
+    expect(MongoClient.connect).toHaveBeenCalledWith(
+      'mongodb://user!with%40%2B%20symbols:password!with%40%2B%20symbols@localhost:1234/parse',
+      jasmine.any(Object)
+    );
+  });
+
+  // https://github.com/ParsePlatform/parse-server/pull/148#issuecomment-180407057
+  it('preserves replica sets', () => {
+    spyOn(MongoClient, 'connect').and.returnValue(Promise.resolve(null));
+    new MongoStorageAdapter('mongodb://test:testpass@ds056315-a0.mongolab.com:59325,ds059315-a1.mongolab.com:59315/testDBname?replicaSet=rs-ds059415', {})
+      .connect();
+    expect(MongoClient.connect).toHaveBeenCalledWith(
+      'mongodb://test:testpass@ds056315-a0.mongolab.com:59325,ds059315-a1.mongolab.com:59315/testDBname?replicaSet=rs-ds059415',
+      jasmine.any(Object)
+    );
+  });
+});