Скачать или смотреть Kotlin TDD - Outside In or Inside Out?

Today we'll look at adding pricing to our product listing from the outside in.

There are two styles of Test Driven Development. When we work inside out, we model the domain and then build whole features by bolting together the models that we have built. This can work well when we are experienced, but risks building low level code that can't actually implement a particular feature.

The alternative, Outside In TDD, starts by implementing a feature against fake or mock low level models as interfaces, and then implements these interfaces with real versions. This way we know that we can implement the feature, even if we don't know how hard it will be to replace the fakes with production code.

Inside out is also known as Classic TDD, sometimes the Chicago School. Outside in is associated with the London eXtreme Tuesday Club, and popularised by Steve Freeman and my co-author Nat Price in Growing Object Oriented Software Guided By Tests.

This is Part 39 of an exploration of where a Test Driven Development implementation of the Gilded Rose stock control system might take us in Kotlin. You can see the whole series as a playlist
   • All Gilded Rose Episodes  
and the code on GitHub https://github.com/dmcg/gilded-rose-tdd

If you like this, you’ll probably like the book Java to Kotlin, A Refactoring Guidebook
http://java-to-kotlin.dev. We have a whole chapter, "Maps to Mocks", covering using replacing mocks with functions implemented by Map::getValue.