TestDriven Development, Why How and Smells
- 2. Scrum is Hot, but… Many Scrum teams are struggling • Slow down (fewer features/sprint) – More and more production issues – Increased fragility • Requests for ‘refactoring’ stories from development team
- 3. Scrum is Hot, but… • Regression testing is demanded – Takes up lots of time in a sprint – Sprints start to lengthen • Documentation becomes an issue because Agile teams “don’t do” documentation. • Technical debt is introduced via “Copy and paste coding”.
- 4. 10 Year Agile Manifesto meet up 2011 concluded “As a group, we agreed on the following four belief statements: •Demand technical excellence •Promote individual change and lead organizational change •Organize knowledge and improve education •Maximize value creation across the entire process”
- 5. Combine Scrum with XP
- 9. Uncle Bob About TDD “The act of writing a unit test is more an act of design than of verification. It is also more an act of documentation than of verification. The act of writing a unit test closes a remarkable number of feedback loops, the least of which is the one pertaining to verification of function”
- 10. Kent Beck about TDD “TDD encourages simple designs and inspires confidence”
- 12. About Unit Testing “A procedure used to validate that individual units of source code are working properly. A unit is the smallest testable part of an application. In procedural programming a unit may be an individual program, function, procedure, etc., while in object oriented programming, the smallest unit is a method.”
- 13. Why Unit Tests? • Avoid Combinatorial Complexity • Fine grained makes it easy to pin-point defects • Coded documentation that stays in sync • Supports changing the code • Supports collective code ownership
- 14. Source: Agile in a Flash by Jeff Langr and Tim Ottinger
- 16. Things we forget while coding • SOLID principle – Lower Complexity – Loosely Coupled – Tighter cohesion • Keep focus on Simple Design – YAGNI, DRY • Continues Refactoring
- 18. Source: Agile in a Flash by Jeff Langr and Tim Ottinger
- 19. TDD mantras
- 20. TDD mantras Given, When, Then or Arrange, Act, Assert
- 21. Source: Agile in a Flash by Jeff Langr and Tim Ottinger
- 22. Source: Agile in a Flash by Jeff Langr and Tim Ottinger
- 23. START NOW!