Code Review for Teams Too Busy to Review Code Brendan Humphreys, Atlassian

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2. Code Review for Busy Teams
A guide for chronically time-poor developers
Brendan Humphreys, Atlassian
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3. Who am I?
• @brendanh
• Team Lead, FishEye & Crucible
• 12+ years experience doing code review
• 12+ years of trying to do code review better
•
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4. Topics
• Back to basics
• How to we got to where we are
• Three steps towards code review
• Strategies & hurdles
• Some tips for better reviews
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5. #include <stdio.h>
main(t,_,a)char *a;{return!0<t?t<3?main(-79,-13,a+main(-87,1-_,
main(-86,0,a+1)+a)):1,t<_?main(t+1,_,a):3,main(-94,-27+t,a)&&t==2?_<13?
main(2,_+1,"%s %d %dn"):9:16:t<0?t<-72?main(_,t,
"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l,+,/n{n+,/+#n+,/#
;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l
q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;#
){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw'
iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c
;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')#
}'+}##(!!/")
:t<-50?_==*a?putchar(31[a]):main(-65,_,a+1):main((*a=='/')+t,_,a+1)
:0<t?main(2,2,"%s"):*a=='/'||main(0,main(-61,*a,
"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:nuwloca-O;m .vpbks,fxntdCeghiry"),a+1);}
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6. What is it that we do all day?
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10. Relative cost of fixing a bug
$$$
Req. Design Coding Testing QA Production
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11. $500 million
payload
1 line
software
defect
$8 billion
rocket
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13. The Rise of Agile
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18. Machines vs Humans
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19. blocky:~ brendan$ javac hello.java
hello.java:6: cannot find symbol
symbol : variable length
location: class java.lang.String
for (int i = 0; i < s.length; i++) {
^
1 error
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22. Smarter Tools
•Checkstyle, Lint, PMD
•Findbugs
•Clover
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23. Continuous Feedback
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24. Tougher Questions
}
• Meet requirements?
• Architecturally sound?
• Futureproof? Code
• Coding idioms correct? Review
• Potential reuse
• Domain knowledge
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26. Code Review
• “Systematic review of code by peers”
• reduce defects
• spread code ownership
• mentor developers
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27. Formal Code Inspection
Fagan, 1976
Finds Defects Early!
Great for mentoring, knowledge sharing
Printed Source code!
Rigid process,
Face-to-face meetings!
Very slow
Impractical for large
codebases
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28. Pair Programming
Very effective code review, finds
defects early
Great for sharing knowledge,
mentoring
Requires two developers,
co-located
Transient discussion
Personalities
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29. Tool-assisted Code Review
•Managed workflow and notification
•Record of discussion
•Asynchronous
•Change team culture?
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30. 3 steps towards a code review
culture
•Make activity visible
•Make code sharable
•Encourage discussions around code
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31. Making Activity Visible
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32. FishEye: Unlock your repository
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33. Making Activity Visible
• The FishEye
Activity Stream
• Web
• RSS
• Watches
• JIRA
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35. Making Code Sharable
• FishEye makes it easy to share code
pointers
• File revisions
• Source Lines
• Diffs
• ChangeSets
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36. Encouraging
Discussions
Around code
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37. Crucible: Lightweight Code Review
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38. Crucible: ChangeSet Discussions
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40. ChangeSet Discussions
• Simple way to provide ad-hoc feedback
• Threaded discussions
• ChangeSet author notified
• Appear in Activity Stream
• Preserved as annotation to ChangeSet
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41. Crucible: Snippets
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43. Snippets
• Simple “paste-bin” service
• Anyone can comment, reply, raise defect
• All participants notified
• Appear in activity stream
• Durable, sharable
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44. Crucible: “formal” review
• Simple workflow
• draft, review, summarize, close
• Manage review workload
• target particular reviewers
• Advanced features
• Pre-commit, Iterative, create from JIRA
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46. How to get started
•Go slow
•Just the diffs
•Review the scariest code!
•On demand
•On assignment
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47. Common Hurdles to Adoption
• “It takes too much time”
• "Code reviews can get nasty"
• "We have to stick to XYZ process"
• "I don't want to leave my IDE"
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48. Four tips for better reviews
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49. #1:
Strive for
Ego-Free
Reviews
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50. #1: Ego-Free Reviews
• No personal Pronouns
• No point scoring
• Moderator to police
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51. #2:
Don’t be a
Pedant
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52. #2: Don’t be a Pedant
• Use tools to enforce errors
style, catch common
coding
• Look for the forest, not the
trees
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53. #3: Find
Problems,
Not Solutions
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54. #3: Find Problems, Not Solutions
• Except for trivial fixes
• Pair program instead
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55. #4: Embrace Feedback
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56. #4: Embrace Feedback
• You will learn from it!
• You will learn to love it!
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57. #include <stdio.h>
main(t,_,a)char *a;{return!0<t?t<3?main(-79,-13,a+main(-87,1-_,
main(-86,0,a+1)+a)):1,t<_?main(t+1,_,a):3,main(-94,-27+t,a)&&t==2?_<13?
main(2,_+1,"%s %d %dn"):9:16:t<0?t<-72?main(_,t,
"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l,+,/n{n+,/+#n+,/#
;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l
q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;#
){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw'
iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c
;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')#
}'+}##(!!/")
:t<-50?_==*a?putchar(31[a]):main(-65,_,a+1):main((*a=='/')+t,_,a+1)
:0<t?main(2,2,"%s"):*a=='/'||main(0,main(-61,*a,
"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:nuwloca-O;m .vpbks,fxntdCeghiry"),a+1);}
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58. blocky:~ brendan$ ./a.out
On the first day of Christmas my true love gave to me
a partridge in a pear tree.
On the second day of Christmas my true love gave to me
two turtle doves
and a partridge in a pear tree.
On the third day of Christmas my true love gave to me
three french hens, two turtle doves
and a partridge in a pear tree.
On the fourth day of Christmas my true love gave to me
four calling birds, three french hens, two turtle doves
and a partridge in a pear tree.
On the fifth day of Christmas my true love gave to me
five gold rings;
four calling birds, three french hens, two turtle doves
and a partridge in a pear tree.
On the sixth day of Christmas my true love gave to me
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59. #include <stdio.h>
main(t,_,a)char *a;{return!0<t?t<3?main(-79,-13,a+main(-87,1-_,
main(-86,0,a+1)+a)):1,t<_?main(t+1,_,a):3,main(-94,-27+t,a)&&t==2?_<13?
main(2,_+1,"%s %d %dn"):9:16:t<0?t<-72?main(_,t,
"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l,+,/n{n+,/+#n+,/#
;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l
q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;#
){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw'
iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c
;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')#
}'+}##(!!/")
:t<-50?_==*a?putchar(31[a]):main(-65,_,a+1):main((*a=='/')+t,_,a+1)
:0<t?main(2,2,"%s"):*a=='/'||main(0,main(-61,*a,
"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:nuwloca-O;m .vpbks,fxntdCeghiry"),a+1);}
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