Sunday, March 23, 2008
Testing? Aren't I a Developer?

Aren't developers just supposed to write their code and let the test team test it?

ahem.

no.

As a developer, I take pride in delivering *working* software. If I don't test my own software, I think that I'm really failing to do my job. Testing is not just for "testers."

As a professional software engineer, I need have not only unit tests for my code (a Development practice by the way), but I also need to write automated functional tests to make sure that all the functionality works as I think it should. Then, I need to have automated Acceptance tests that tell me if indeed the whole system works together to deliver the business solution that the story or requirements describe.

Acceptance Tests
  Why do I start with acceptance tests?

Because... they should drive the entire development process. Test-Driven Development doesn't necessarily have to *always* mean Unit Test-Driven Development...

The Acceptance tests drive me to write code.
In order to write code, I need a unit test.
Then I can write the code that passes the unit test and the acceptance test.

job well done.

Unit Tests
  I write enough unit tests to be able to make sure that the functionality I write works as I intended. Not too many - tests require maintenance as well as the code they test - but enough to ensure that it's safe to refactor just about anything in the code and make sure that it still works as intended. This is the safety net that unit tests provide.

Code
  Write some. It should make the tests pass. Failure is not an option.

Functional Tests
  We need to make sure that all the pieces of functionality behave in a known way. This is what functional testing does.



Integration Tests
  We need to make sure that all the systems co-operate. Integration tests are deeper yet than functional tests, these are more like "end-to-end" tests of particular scenarios. Usually these scenarios cover all the happy paths of end-to-end, and most likely a couple of failure scenarios as well, to illustrate how the system overall behaves in failure modes.

Deployment Tests
  You DID want to INSTALL the software and use it, right?

So... you got a test for that?

Sure you do.

Deployment tests are essential for making sure the software delivers and configures the binary bits in a way that's useful to the user. Uninstall is a particularly critical issue as well. Make sure that you have complete testing around these critical fundamental features of the software.

ATDD | TDD | Testing
Sunday, March 23, 2008 9:47:08 PM (Pacific Standard Time, UTC-08:00)  #    Comments [0]  | 
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