public void CanUpdate() { // setup string tweet1 = "Hello world"; string tweet2 = "World Hello"; // record Expect.Call(_twitterApiClient.UpdateWithSource(tweet1, TweetsManager.APP_NAME)).Return(new Status { Text = tweet1 }); Expect.Call(_twitterApiClient.UpdateWithSource(tweet2, TweetsManager.APP_NAME)).Return(new Status { Text = tweet2 }); // playback _mocks.ReplayAll(); _tweetsManager.Update(tweet1); _tweetsManager.Update(tweet2); // assert Assert.AreEqual(2, _tweetsManager.All.Count); Assert.AreEqual(tweet2, _tweetsManager.All[0].Text); Assert.AreEqual(tweet1, _tweetsManager.All[1].Text); _mocks.VerifyAll(); }