TDD Overview. Efficient Bug fixing

Transcript

1. TDD Overview. Efficient bug fixing by Vladislav Matelski
2. About me contact@vladds.com Lead software engineer Vladislav Matelski Icons made by Freepik from Flaticon are licensed by CC 3.0 BY
3. Agenda 1. TDD Overview 2. TDD Overview Overview 3. Efficient Bug fixing 4. Q&A
4. TDD Overview
5. Kent Beck “Rather than apply minutes of suspect reasoning, we can just ask the computer by making the change and running the tests.” Test Driven Development: By Example
6. Laws of TDD 1. You can’t write any production code until you have fi rst written a failing unit test. 2. You can’t write more of a unit test than is su ffi cient to fail, and not compiling is failing. 3. You can’t write more production code than is su ff i cient to pass the currently failing unit test.
7. TDD Overview
8. TDD Overview 1. Iterative process 2. Tests First 3. The simplest thing that should work
9. DEMO
10. TDD Advantages • design before you code • documentation for design • proof that code implements design • encouraging design of testable code
11. TDD Caveats • some things are too hard to test • some tests are too trivial • over-testing is possible • test cycle should take little time
12. Kent Beck “ Do The Simplest Thing That Could Possibly Work”
13. TDD Overview Overview
14. Kent Beck “I'm not a great programmer; I'm just a good programmer with great habits.”
15. TDD Overview Overview TDD is a process When the same thing gets repeated over and over It may look as just a waste of time And we could have written code faster if we didn’t write tests!
16. Why should I spend time on washing my hands!? I would have saved more people if I didn’t! TDD Overview Overview
17. Why should we engineer this building!? 
 
 Just give us bricks! TDD Overview Overview
18. TDD Overview Overview Process No Process Surgery Cutting People Open Architecture Putting bricks Software Engineering Programming
19. Aristotle “Quality is not an act, it is a habit.”
20. Efficient Bug Fixing
21. Fail fast • code style • test coverage • CI • code quality tools • knowledge sharing Efficient bug fixing
22. Bram Cohen “The trick is to fix the problem you have, rather than the problem you want.”
23. • Don’t panic • Reproduce the bug • Understand the root cause • understand the expected behavior • fi nd misbehaving place in the code • look around for similar patterns Bug Analysis
24. • implement the correction • test the correction • clean the code • test the correction again Correction of the bug
25. Richard Pattis “When debugging, novices insert corrective code; experts remove defective code.” Senior lecturer at University of California, Irvine
26. Q&A
27. Thanks!