Question

I’m starting a new project and I want to use Test Driven Development, but I having trouble understanding how to write tests when you don’t have a data model or interfaces.

IMO, the data model and interfaces should be written. Then a couple of features should be implemented to verify the data model and interfaces have “matured.” (aka changes to either will be minimal). Then I would write the unit tests. After that step, I think you can follow TDD.

Is this the correct approach?

On a side note, does it seem like some of these new techniques like TDD don’t account or document what to do for new projects.

Answer 1

Like they say, “start with a failing unit test”.

• You don’t need a data model until and unless it’s needed in order to fix a failing unit test.
• You don’t need interfaces until they’re necessary (to fix a failing unit test)

Maybe if you give an example of an application, we can help you find the first few failing tests.