How to test APIs

Question

I've started unit testing and I'm trying to perform unit tests on an API wrapper I built for a WSDL Resource I'm using.

I can unit test my classes just fine, but what are the best practices for testing the external API? Should I ever bother testing it? Aside from the tests I to verify connection and parameters and stuff, what are the best methods for making sure my data got properly updated(if I should even be doing that)?

Answer 1

What your seeking is called Blackbox Testing which stands basically for testing functionallity of the API instead of its structure.

What you normally look for is:

• Incorrect or missing functions
• Interface errors
• Errors in data structures or external database access
• Behaviour or performance errors
• Initialization and termination errors

Google for Equivalence Partitioning and Boundary Value Analysis. That should give you an idea of what to test and how.