Ok, this was a good article. And the explanation of all the APIs!!!!
Incidentally, I was looking for more resources to understand sentiment analysis, but my focus was trading. A digression, snapped up a course on Quantra when they introduced Sentiment Analysis in Trading.
At recruiterbox, we try to practice test driven development — our test coverage is above 80%. We have a mix of unit tests, integration tests and functional tests. Our ratio of unit tests to integration tests is not great but reasonable.