Although software developers are usually reluctant to use static analysis to detect issues in their source code, our automatic just-in-time static analysis assistant was integrated into an Integrated Development Environment, and was evaluated positively by its users. We conducted interviews to understand the impact of the tool on experienced developers, and how it performs in comparison with other static analyzers. We learned that the availability of our tool as a default IDE feature and its automatic execution are the main reasons for its adoption. Moreover, the fact that immediate feedback is provided directly in the related development context is essential to keeping developers satisfied, although in certain cases feedback delivered later was deemed more useful. We also discovered that static analyzers can play an educational role, especially in combination with domain- specific rules.

1. JIT Feedback — what Experienced
Developers like about Static Analysis
Yuriy Tymchuk
Swisscom, Switzerland
Mohammad Ghafari
UniBern, Switzerland
Oscar Nierstrasz
UniBern, Switzerland
3

2. How do Developers use Static Analysis
When They use Static Analysis
Mohammad Ghafari
UniBern, Switzerland
Oscar Nierstrasz
UniBern, Switzerland
*WITH A TWIST
4
@yuriy_tymchuk
Swisscom, Switzerland

3. Wouldn’t Make it Alone
Mohammad Oscar
5

4. 6
The research presented here was all
done in the University of Bern.
Nothing Swisscom-related in this
presentation, folks.

5. Static Analyzers
7

6. 8
Static Analyzers

7. 9
Static Analysis Camps

8. 9
Static Analysis Camps

9. 10
Static Analysis Camps
Continuous quality assessment with
inCode.
Ganea, Verebi, Marinescu.
Science of Computer Prog. 2017
Usage contracts: Offering imme-
diate feedback on violations of
structural source-code regularities.
Lozano, Mens, Kellens
Science of Computer Prog. 2015
Using Static Analysis to Find Bugs.
Ayewah, Hovemeyer, Morgenthaler,
Penix, Pugh.
IEEE Software 2008

10. 11
Static Analysis Camps
We have new
useful analyzers!

11. 12
Static Analysis Camps
We have new
useful analyzers!
Analyzing the State of Static
Analysis: A Large-Scale Evaluation
in Open Source Software.
Beller, Bholanath, McIntosh,
Zaidman.
SANER 2016.
Why Don’t Software Developers Use
Static Analysis Tools to Find Bugs?
Johnson, Song, Murphy-Hill,
Bowdidge.
ICSE 2013

12. 13
Static Analysis Camps
We have new
useful analyzers!
Nobody uses
static analyzers

13. 14
Static Analysis Camps
We have new
useful analyzers!
Nobody uses
static analyzers
But they are
not used?

14. 15
Static Analysis Camps
We have new
useful analyzers!
Nobody uses
static analyzers
But they are
not used?
But do they
know about…

15. We shape our tools, and thereafter
our tools shape us. — McLuhan/Culkin
16

16. 17
Context: Pharo

17. 18
Context: Pharo
Object-Oriented
Dynamically Typed

18. 19
Context: Pharo
Object-Oriented
Dynamically Typed
Language and IDE

19. 20
Central Tool: Code Editor

20. 21
Central Tool: Code Editor

21. 22
Intrusive Quality Assistant

22. 23
Is QA Useful or Distracting?

23. 24
0%
20%
40%
< 1 1–3 4–6 7–10 10+
Smalltalk Pharo
N/A
4% Academia 75% Industry 21%
24 Participants
(years)
Is QA Useful or Distracting?
Survey

24. 25
UsefulSOMETIMES
Sometimes Distracting
VERY
Neutral
0% 25% 50% 75% 100%8%
Is QA Useful or Distracting?
Survey
0%
20%
40%
< 1 1–3 4–6 7–10 10+
Smalltalk Pharo
N/A
4% Academia 75% Industry 21%
24 Participants
(years)

25. 26
Why/How Quality Assistant?

26. 27
14 Researcher 36%
Sen. Engineer
14%Engineer 50%
0% 20% 40% 60% 80% 100%
<5 5–10 10–20 20+
0% 20% 40% 60% 80% 100%
<3 3–6 6+
Development Experience Pharo Experience
Interview
Why/How Quality Assistant?
532 5342 392
7 25

27. 28
It’s Always There

28. 29
“No installation required”
“No execution required”
It’s Always There

29. 30
Not Always There

30. 31
Adds a Final Drop
Maybe just once?

31. 32
No!
Adds a Final Drop
Maybe just once?

32. 34
Instant and Scoped Feedback

33. 35

34. 36
Scoped Feedback

35. 37
Scoped Feedback

36. 38
Scoped Feedback
~8.5
~1.5

37. 39
The Bad Side of QA

38. 40
“There is this ‘missing yourself’ rule with many
false positives”
The Bad Side of QA

39. 41
“Uncommented class? Meh…”
The Bad Side of QA
“There is this ‘missing yourself’ rule with many
false positives”

40. 42
“Sometimes not clear what is the problem”
“Uncommented class? Meh…”
The Bad Side of QA
“There is this ‘missing yourself’ rule with many
false positives”

41. 43
“Sometimes not clear what is the problem”
“Takes too much of the editor space”
“Uncommented class? Meh…”
The Bad Side of QA
“There is this ‘missing yourself’ rule with many
false positives”

42. 44
Part of Something More

43. 45
Part of Something More

44. 46
Part of Something More

45. 47
Part of Something More
Fast SlowSlow

46. 48
Part of Something More
Fast SlowSlow
PersonalPersonal Shared

47. 49
Part of Something More
Fast SlowSlow
PersonalPersonal Shared
Overview Glimpse Summary

48. 50
QualityAssistant as a Teacher

49. 51
QualityAssistant as a Teacher
nodes select: [ :node | node isUsed not ]

50. 52
QualityAssistant as a Teacher
nodes select: [ :node | node isUsed not ]
nodes reject: [ :node | node isUsed ]
“I learned how to program better”
— Student

51. 53
QA as Communication Medium

52. 54
QA as Communication Medium

53. 55
QA as Communication Medium

54. 55
QA as Communication Medium

55. 56
QA as Communication Medium

56. 56
QA as Communication Medium

57. 57
QA as Communication Medium
return presentation.list()
.title("Best movies")
.display(...)
.sorting(...)
.items(downloadMovies())

58. 58
QA as Communication Medium
return presentation.list()
.title("Best movies")
.display(...)
.sorting(...)
.items(downloadMovies())

59. 59
QA as Communication Medium
return presentation.list()
.title("Best movies")
.display(...)
.sorting(...)
.items(λ(downloadMovies()))

60. 60
QA as Communication Medium

61. 61
QA as Communication Medium

62. 62
QA as Communication Medium
“The most
useful rules!”

63. 63
Automatic,constant feedback

64. 64
Automatic,constant feedback
Narrow,contextual scope

65. 65
Automatic,constant feedback
Static analysis as a teacher
Narrow,contextual scope

66. 66
Automatic,constant feedback
Static analysis as a teacher
Narrow,contextual scope
Common static analysis issues

67. 67
Do you want to see developers
using static analyzers?