Refactoring & Testing software.
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The document discusses the challenges of refactoring and testing a legacy software application with over 60 bugs and 70 enhancements. It emphasizes the importance of improving code design while preserving functionality, using industry techniques, and implementing robust testing practices like unit tests to maintain user trust. Key questions addressed include necessary changes, verification of correctness, and ensuring stability during refactoring.
Refactoring & Testing software.
- 1. REFACTORING AND TESTING SOFTWARE By: Stephen O’Dwyer
- 2. SUPPORTED LEGACY APPLICATION System is a main value driver Main system current state 60+ REPORTED bugs 70+ enhancements Managed by many teams and developers Refactoring and acceptance testing A way to advance the legacy system to a usable state Manageable for developers
- 3. LEGACY CODE Legacy code is Code we’ve gotten from someone else Slang for difficult to change code that developers don’t understand No acceptance, unit or integration test
- 4. BEHAVIOR OF SYSTEM Users depend on behavior Adding new features currently follows the edit and pray mentality Edit code base and pray it dose not have adverse side effects Users trust Trust is lost when changing functionality unintentionally and unknowingly
- 5. REFACTORING The act of improving design wile preserving existing functionality Time consuming in the beginning Use Industry refactoring techniques Sprout Method and class Reveal hidden dependency Identify Interception points Reduce constructor blob
- 6. REDUCE RISK OF REFACTORING QUESTIONS 1. What changes do we have to make? 2. How will we know that we’ve done them correctly? 3. How will we know that we haven’t broken anything?
- 7. TESTING Regression Performed by QA team Unit test A piece of code that checks the correctness of production code Frameworks XUnit NUnit
- 8. QUALITY TEST 1. They run fast 2. They help us localize problems
- 9. CODE DEMO
- 10. CALL TO ACTION Write your first unit test Refactor a method Buy and read Working Effectively with Legacy code by Michael Feathers
- 11. REFERENCES Feathers, Michael - Working Effectively with Legacy Code Roy Osherove – The Art of Unit Testing