* Much of ansible's testing needs are in integration, not unit tests. We're working on releasing wide array of integration tests that use modules in a live environment.
* That being said, there are unit tests
* Code written must absolutely pass unit tests (i.e. "make tests")
* Much of ansible's testing needs are in integration, not unit tests. Add module tests there.
* That being said, there are unit tests too!
* Code written must absolutely pass tests (i.e. "make tests")
* You should anticipate any error paths in your code and test down those error paths.
* Additions to unit tests for core code is welcome, but modules tend to be more integration-testey, so it's not always possible to add them (examples: ec2, etc).
* Additions to tests for core code is welcome, but not always possible. Be sure things are at least well tested manually in that case.