Code Review for iOS
- 2. Agenda • Goals • Types of Code Review • Tips for Developers during Code Review • Tips for Reviewers during Code Review • General Guidelines • Control Structures • Error Handling • Resource Leaks • Performance • Maintainability and Reusability
- 3. Goal
- 4. • To spot and fix defects early in the process
- 5. • Helps to maintain a level of consistency in design and implementation
- 6. • Better shared understanding of the code base as team members learn from each other
- 8. Formal Code Review • Involves software developers meeting together and reviewing relevant code line by line many times taking the opportunity to analyze printed copies of the materials
- 9. Peer Code Review • Can be done over the shoulder where the reviewer looks over the author’s shoulder as the other goes through the code • Or can be done via email or version control system like Git and online conference
- 10. Tips for Developers during Code Review
- 11. • The primary reviewer is the author. • You
- 12. • Create a checklist for yourself of the things that the code reviews tend to focus on
- 13. • Understand and accept that you will make mistakes
- 14. • No matter how much your knowledge is, someone else will always know more than you
- 15. • Don’t rewrite code without consultation
- 16. • The only constant thing in this world is change
- 17. • Fight for what you believe, but gracefully accept defeat
- 18. • Please note that review meetings are not problem solving meetings
- 19. • Helping to maintain the coding standards
- 20. Tips for Reviewers during Code Review
- 21. • Critique code instead of people – be kind to the coder, not to the code
- 22. • Treat people who know less than you with respect, deference and patience
- 23. • Ask questions rather than make statements
- 24. • Avoid the why questions
- 25. • Remember to praise
- 26. • Make sure you have good coding standards to reference
- 27. • Remember that there is often more than one way to approach a solution
- 28. • You should not rush through a code review – but also, you need to do it promptly
- 29. • Review fewer than 200 – 400 lines of code at a time
- 31. • Is the code following coding guidelines and naming conventions? • Reviewer should have a reference for coding guidelines and conventions
- 32. • Are all compiler warnings fixed?
- 33. • Are there leftover code for testing/development?
- 34. • Is the code complexity under the maximum allowable threshold for a given metric? • *a class is less than 500 lines • *a method does not contain more than 15 control structures
- 36. • Check for infinite loops?
- 37. • Does the loop iterate the correct number of times?
- 38. Error Handling
- 39. • Does the code check for null exceptions?
- 40. • Does the code check for array out of bounds exceptions?
- 41. Resource Leaks
- 42. • Are all allocated memory freed?
- 43. • Do all classes perform thorough cleanup on its destructor (dealloc)?
- 44. • Are all notification observers, event listeners, message receivers or gesture recognizers removed when not needed?
- 45. • Does the code accurately keep track of reference counting?
- 46. Performance
- 47. • Are you using blocking system calls when performance is involved?
- 48. • Will the same data be reloaded often?
- 49. • Will caching data improve performance?
- 50. • Is a large number of big objects being created and destroyed in a small amount of time?
- 51. • Will reusing objects improve performance?
- 52. • Was this optimization really needed?
- 54. • Is the code using magic numbers and magic strings?
- 55. • Does the code comply with the DRY (Don’t Repeat Yourself) principle?
- 56. Thank you!