It’s not easy to perform a good code review. Often done in a hurry just to get it done, it only makes things worse. People treat it as an obstacle, not a helpful thing. I am gonna tell you why code reviews are important and how they can help you maintain good quality code. I will not only tell who are the code reviews for, how to raise a useful code review, but also how to perform a good code review in the quickest time possible.

1. code reviews
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2. • a Pole living in Sheffield
• over 12 years in
development
• Pascal, C++, PHP, perl,
python, Java
• co-author of 2 PHP
books
• big fan of process
automation
• TDD and CI
• occasionally contributes
to open source projects
• wants to be a knight
https://joind.in/6947
@proofek

3. Who does code reviews?

4. All characters
appearing in this
presentation are
fictitious.
Any resemblance to
real persons, living or
dead, is purely
coincidental.
Disclaimer

5. Tom “I Need It Now” –
The Owner
Harry “Just Get It Done” –
The Manager
The Team

6. Adam “The Night Coder” –
developer
Kris “Hackety Hack” –
master code reviewer
Bruno “It Will Work” –
apprentice reviewer
The Team

7. How much time do we need to
get this project done?
Well, design, coding, code
reviews, testing…
Do we really need to code review the
code? You surely know how to code,
and you have tested it and it works…
Right?
Scenario 1

8. We're nearly done, just need
to get this code reviewed.
Hmmm… all the developers are busy,
we have no one spare. Let's skip it and
get it straight into QA…
Scenario 2

9. Hello Harry,
I need John to review my code.
John is busy, you can have Rob.
But Rob is a junior developer, and
he doesn't know this system.
You want it code reviewed or
not? Rob is all we've got!
Scenario 3

10. We do all these code review, spend
a lot of time on this, but the code
that hits production is still buggy.
It's a waste of time!
Scenario 4

11. Code review
Adam The Developer 9:31 PM (0 minutes ago)
to Kris The Reviewer
Kris,
I got this code I need you to review.
Can you do it for me please? The code is in my repository on problem-fix branch.
Thanks
---
Adam
Click here to Reply or Forward

12. No (e)mail!
Raising a code review

13. Bug tracking systems
- JIRA
- Bugtrak
- Mantis
Code review tools
- Crucible/Fisheye
- Gerrit
- Github
Raising a code review

14. Code review
Adam The Developer 9:31 PM (13 minutes ago)
to Kris The Reviewer
Kris,
I got this code I need you to review.
Can you do it for me please? The code is in my repository on problem-fix branch.
Thanks
---
Adam
Kris The Reviewer 9:44 PM (0 minutes ago)
to Adam The Developer
Adam,
No problem at all, but where did you branch the code from?
I can’t identify the change set without it.
---
Kris
Click here to Reply or Forward

15. Version control
• Specific change
sets
• avoid specific
commits
• Reviewing patches
risky, unless
automated
What to review

16. Code review
Adam The Developer 9:31 PM (25 minutes ago)
Kris, I got this code I need you to review. Can you do it for me please? …
Kris The Reviewer 9:44 PM (12 minutes ago)
to Adam The Developer
Adam,
No problem at all, but where did you branch the code from?
I can’t identify the change set without it.
---
Kris
Adam The Developer 9:56 PM (0 minutes ago)
to Kris The Reviewer
Kris,
Ah yes. Sorry. It’s branched from my master branch.
---
Adam

17. What
and
Why?
The purpose of the review

18. Bruno “It will work”
Usual feedback produced:
• Makes sense
• Works
• Syntactically correct
• Approved
One way of doing things…

19. Kris “The Master
Reviewer”
Tools used:
• PHP linter
• PHP Code Sniffer
• PHPUnit
• phpDocumentor
• PHP Depend
• PHP Mess Detector
• Sonar
Being smarter…

20. $ php -l Libraries/Action.class.php
No syntax errors detected in Libraries/Action.class.php
$ php -l Libraries/Action.class.php
Errors parsing Libraries/Action.class.php
$ phpcs –standard=Zend Libraries/Action.class.php
FILE: /Volumes/git/modules/AccountChange/Libraries/Action.class.php
--------------------------------------------------------------------------------
FOUND 2 ERROR(S) AND 1 WARNING(S) AFFECTING 3 LINE(S)
--------------------------------------------------------------------------------
44 | ERROR | Protected member variable "arrOptions" must contain a leading
| | underscore
66 | WARNING | Line exceeds 80 characters; contains 82 characters
97 | ERROR | Line exceeds maximum limit of 120 characters; contains 135
| | characters
--------------------------------------------------------------------------------
Time: 0 seconds, Memory: 5.75Mb
Speed up with automation - PHP linter and PHP CodeSniffer

21. $ phpunit
PHPUnit 3.6.12 by Sebastian Bergmann.
Configuration read from phpunit.xml.dist
..................IIII................IIIIIIIIIIIIIIIIIIIIIII.. 63 / 240 ( 26%)
.............................................I.....I........... 126 / 240 ( 52%)
............................................................... 189 / 240 ( 78%)
...................................................
Time: 02:01, Memory: 26.75Mb
OK, but incomplete or skipped tests!
Tests: 240, Assertions: 514, Incomplete: 29.
Verify whether the code works with PHPUnit

22. PHP_Depend 0.10.6 by Manuel Pichler
Parsing source files:
.................... 20
Executing CyclomaticComplexity-Analyzer:
............. 261
Executing ClassLevel-Analyzer:
............ 247
Executing CodeRank-Analyzer:
. 28
Executing Coupling-Analyzer:
............. 267
Executing Hierarchy-Analyzer:
............ 246
Executing Inheritance-Analyzer:
. 30
Executing NPathComplexity-Analyzer:
.............. 283
Executing NodeCount-Analyzer:
........ 174
Executing NodeLoc-Analyzer:
.......... 205
Generating pdepend log files, this may take a moment.
Time: 00:05; Memory: 25.50Mb
Static analysis and code quality with PHP Depend

23. Static analysis and code quality with PHP Mess Detector

24. Static analysis and code quality with Sonar

25. Static analysis and code quality with Sonar

26. Static analysis and code quality with Sonar

27. Static analysis and code quality with Sonar

28. Static analysis and code quality with Sonar

29. Static analysis and code quality with Sonar

30. Kris “The Master
Reviewer”
Things checked:
• clarity • duplications
• performance • code quality
• excessive complexity • potential deployment
• impact on other issues
systems • design flaws
• does the solution
solves the problem
…by looking at things all important

31. • Knowledge sharing
• Mentoring new starters
• Find bugs/design flaws
early
• Improve overall code quality
• Fostering collective code
ownership
The benefits of a code review – they are for you!

32. DEVELOPERS
• Understand and accept that you will make
mistakes.
• You are not your code.
• No matter how much "karate" you know,
someone else will always know more.
• Don't rewrite code without consultation.
The soft side - developers

33. CODE REVIEWERS
• The only true authority stems from
knowledge, not from position.
• Critique code instead of people
The soft side – code reviewers

34. • Location of your changes
WHAT?
– Repository name, branch name, branch base
• Subject of your changes
– What have you changed
• Reason for the change
– Why have you change it
Summary - what include in the code review

35. WHO?
• Seek the experts
– If you're not sure ask around
• Question the solution
– Make sure it fits the purpose
Summary - who assign the code review to?

36. WHERE?
• Make it traceable
– Bug trucking system, ie. Jira, Trac, Mantis, etc
– Code review tool, ie. Fisheye/Crucible, gerrit
• Conversation/Pair programming
– Just make sure outcome is captured
Summary – where to raise a code review?

37. • Use tools, don’t be a tool
• Check for duplications/
HOW?
complexity
• Asses impact on other systems
• Make sure code is clear and
self-descriptive
Summary - how to perform a good code review?

39. http://www.atlassian.com/angrynerds/
http://georgegant.deviantart.com/art/Angry-Nerds-217554774
http://www.flickr.com/photos/dawgbyte77/3058349367/
http://www.flickr.com/photos/zzpza/3269784239/
http://www.flickr.com/photos/toolmantim/6170448143/
http://www.flickr.com/photos/coyau/7630782996/
http://www.flickr.com/photos/73885983@N02/6729908421/
http://www.osnews.com/story/19266/WTFs_m
Credits…

40. The Ten Commandments of Egoless Programming: http://alturl.com/
q4dpa
The Code review: http://www.soulbroken.co.uk/blog/2010/07/the-code-
review/
Fisheye/Crucible: http://www.atlassian.com/software/crucible/overview
Gerrit: http://code.google.com/p/gerrit/
Github: https://github.com/
PHPUnit: http://phpunit.de
PHP CodeSniffer: http://pear.php.net/PHP_CodeSniffer
PHP Depend: http://pdepend.org/
PHP Mess Detector: http://phpmd.org/
Sonar: http://www.sonarsource.org/
…and references

41. Questions?
https:// /6947
Q&A