How to automate integration testing?

Question

I\'d like to know something, I know that to make your test easier you should use mock during unit testing to only test the component you want, without external dependencies. But

Answer 1

I'd like to know how do you do in the real world ?

In the real world there isn't a simple prescription about what to do, but there is one guiding truth: you want to catch mistake/bugs/test failures as soon as possible after they are introduced. Let that be your guide; everything else is technique.

A couple common techniques:

• Tests running in parallel. This is my preference; I like to have two systems, each running their own instance of CruiseControl* (which I'm a committer for), one running the unit tests with fast feedback (< 5 minutes) while another system runs the integration tests constantly. I like this because it minimizes the delay between when a checkin happens and a system test might catch it. The downside that some people don't like is that you can end up with multiple test failures for the same checkin, both a unit test failure and an integration test failure. I don't find this a major downside in practice.

• A life-cycle model where system/integration tests run only after unit tests have passed. There are tools like AnthillPro* that are built around this kind of model and the approach is very popular. In their model they take the artifacts that have passed the unit tests, deploy them to a separate staging server, and then run the system/integration tests there.

If you've more questions about this topic I'd recommend the Continuous Integration and Testing Conference (CITCON) and/or the CITCON mailing list.

• There are lots of CI and build|process automation tools out there. These are just representatives of their class of tools.