MatteoVaccariBirthdayGreetingsKataInSCBCN2013

Presentation for Matteo Vaccari's Birthday Greetings Refactoring Kata that we did in SCBCN

Transcript

1. Birthday Greetings Kata Manuel Rivero @trikitrok
2. The kata ­ Created by Matteo Vaccari. ­ Alistair Cockburn's: Ports and Adapters. a. k. a. Hexagonal Architecture ­ Refactoring version.
3. The initial code  Clone it from: https://github.com/trikitrok/BirthdayGreetingsKata SCBCN2013InitialCode
4. The initial code 1. Read employee records from a file. 2. Filter employees whose birthday is today. 3. Send a personalized greetings message by email.
5. Problems  BirthdayService  Has too many responsibilities.  Depends on low level APIs.  Talks with external systems.  ...
6. Ports and Adapters
7. In the ports and adapters architecture  Domain Model depends on nothing  Everything depends on the domain model
8. Ports and Adapters
9. Benefits  Easier to change as requirements change  Easier to test  Easier to understand
10. Ports and Adapters
11. Ports and Adapters
12. Ports and Adapters  Port Façade (interface) →  Adapter Concrete → implementation
13. Ports and Adapters
14. Refactoring technique  Small steps!  Keep tests green at all times!
15. Refactoring approach 1. Identify a responsibility 2. Extract a method 3. Create a new class 4. Move that method to the new class
16. Refactoring guides  Single Responsibility Principle  First at function level, then at class level.  Dependency Inversion Principle
18. Let's start!