How to stop wasting your time and start performing useful code reviews

Devoxx Belgium 2015

Transcript

1. @mariakhalusova #Devoxx #UsefulCodeReview How to stop wasting your time and start performing useful code reviews Maria Khalusova JetBrains
2. @mariakhalusova #Devoxx #UsefulCodeReview Code review • Team collaboration • Knowledge sharing • Faster on-boarding • Increased bus factor • Improved code quality • Easier code maintenance • Finding bugs Better team Better software
3. @mariakhalusova #Devoxx #UsefulCodeReview https://twitter.com/pcweenies/status/649954658794913792
4. @mariakhalusova #Devoxx #UsefulCodeReview Contents • Smooth start • Making code reviews useful • What to look for in a code review • Human factor
5. @mariakhalusova #Devoxx #UsefulCodeReview Where to start? Key aspects: • Team • Change impact • Process • New tool
6. @mariakhalusova #Devoxx #UsefulCodeReview The Team • Communicate clearly • Listen to concerns • Cultivate code review culture
7. @mariakhalusova #Devoxx #UsefulCodeReview Change impact • Who? • What? • When?
8. @mariakhalusova #Devoxx #UsefulCodeReview Process • Decide on the process • Keep workflow simple • Iterations are good • Average 2 reviewers • Review often
9. @mariakhalusova #Devoxx #UsefulCodeReview New tool • Yes, you need a code review tool • Find the right tool: • Fits in your environment • Supports chosen workflow • Meets your particular needs • Keeps you in the loop without spamming
10. @mariakhalusova #Devoxx #UsefulCodeReview Summary • Have an open dialog with the team • Have a good plan • Find the right tool
11. @mariakhalusova #Devoxx #UsefulCodeReview Making code reviews useful
12. @mariakhalusova #Devoxx #UsefulCodeReview Automate what can be automated • Tests • Continuous Integration • Static code analysis • Spellchecker • etc.
13. @mariakhalusova #Devoxx #UsefulCodeReview Code review is not a place for coding style wars
14. @mariakhalusova #Devoxx #UsefulCodeReview As a code author • Review your own code • Commit small changes • Document your code • Provide meaningful commit message
15. @mariakhalusova #Devoxx #UsefulCodeReview As a reviewer • Don’t postpone it • Don’t spend too much time • Keep in mind your project’s priorities • Apply your expertise
16. @mariakhalusova #Devoxx #UsefulCodeReview What to look for?
17. @mariakhalusova #Devoxx #UsefulCodeReview General and business logic • Correctness • Coding errors • Business rules and logic • User facing messages
18. @mariakhalusova #Devoxx #UsefulCodeReview Architecture and design • Is the code in the right place? • Reusability • Data structures • SOLID principles • YAGNI
19. @mariakhalusova #Devoxx #UsefulCodeReview Readability and maintainability Always code as if the person who ends up maintaining your code is a violent psychopath who knows where you live. - John F. Woods (1991) • Naming • Readability • Documentation • Test coverage
20. @mariakhalusova #Devoxx #UsefulCodeReview Performance • Performance requirements • Performance tests • Common causes of performance problems: • Unnecessary network calls • Using locks to access shared resources • Potential memory leaks • Not closed connections/streams • Calls to the database
21. @mariakhalusova #Devoxx #UsefulCodeReview Performance: calls to the database
22. @mariakhalusova #Devoxx #UsefulCodeReview Security • Third party libraries • Authentication • Data encryption • Proper management of passports, encryption keys, etc. • Review potential problems
23. @mariakhalusova #Devoxx #UsefulCodeReview Security: useful read • Common weakness enumeration: CWE.mitre.org • OWASP.org Code Review Guide Book v. 2.0 ALPHA
24. @mariakhalusova #Devoxx #UsefulCodeReview Upsource quick wins • Static code analysis • Code navigation • Find usages • IDE plugin
25. @mariakhalusova #Devoxx #UsefulCodeReview Human factor
26. @mariakhalusova #Devoxx #UsefulCodeReview
27. @mariakhalusova #Devoxx #UsefulCodeReview
28. @mariakhalusova #Devoxx #UsefulCodeReview It is personal!
29. @mariakhalusova #Devoxx #UsefulCodeReview Code review level Linus
30. @mariakhalusova #Devoxx #UsefulCodeReview Learn to give feedback • Don’t be rude • Don’t dictate • Ask questions • Engage in a discussion • It’s ok to disagree and argue • Be sensitive to cultural differences
31. @mariakhalusova #Devoxx #UsefulCodeReview
32. @mariakhalusova #Devoxx #UsefulCodeReview Learn to receive feedback • Contain your immediate reaction • Give it a thought • Ask followup questions
33. @mariakhalusova #Devoxx #UsefulCodeReview It doesn’t have to be all criticism Praise good work!
34. @mariakhalusova #Devoxx #UsefulCodeReview Maria Khalusova JetBrains Thank you!