The document discusses the challenges of making legacy applications testable, highlighting issues of limited resources, commitment, and the need for incremental improvements. It emphasizes a systematic approach to testing by breaking down tasks and ensuring quality through automation and clear definitions. The key takeaway is to prioritize small, manageable changes while avoiding compromises on quality.

1. testing the
Legacy
making existing applications testable
without epic efforts
Alex Leonov
alex@knowledgelab.nz
@alexanderleonov

2. Why is it not done yet?
• no people
• no time
• no money

4. Why is it not done yet?
• no people
• no time
• no money
doesn’t hurt enough

6. How to eat an elephant?
• piece
• by
• piece

7. How to make it testable?
• bug
• by
• bug

8. if they say it’s
Impossible
remember that it’s
impossible for them

9. you need to get
The Commitment

11. Old Application
Old Code

12. Automated Tests
Bubble Wrap
Old Application
Old Code
Logic

13. Automated Tests
Bubble Wrap
Old Application
Old Code
Proxy
New Application
Services

14. Automated Tests
Old Application
Old Interfaces
New Application
Interfaces
Services

17. The Easy Way
or
The Good Way

18. The Easy Way
• make code with bugfix testable
• write down gherkins
• hope someone updates them

20. The Good Way
• make bugfix testable
• make “feature” testable
• make executable gherkins
• add this to the Definition of Done

21. Things to Remember
• view features as services
• stateless is better than stateful
• don’t test the whole all the time
• don’t let it slip

22. Recap
• get commitment
• don’t compromise on quality
• automate everything you touch
• bubble-wrap old stuff
• start small and grow over time

23. Alex Leonov
alex@knowledgelab.nz
@alexanderleonov
testing the
Legacy