IMPACT OF CODE OWNERSHIP IMPACT OF CODE OWNERSHIP ON ATIPATTERNS - - PowerPoint PPT Presentation

IMPACT OF CODE OWNERSHIP IMPACT OF CODE OWNERSHIP ON ATIPATTERNS ON ATIPATTERNS

Stéphane BUNOD Engineering school student at Polytech’Montpellier 3 month internship Supervisor : Foutse KHOMH

OUTLINE OUTLINE

• Context
• Goal
• Implementation
• Results
• Conclusion
• Personal experience

CONTEXT CONTEXT

 Foutse’s research interests  Developping techniques and tools to assess the quality of systems  Design patterns, design defects : their impact on the quality of systems and their evolution in systems  Foutse “Antipatterns are more fault prone” . 2012  Christian Bird. Don’t Touch My Code! Examining the Effects of Ownership on Software Quality. 2011

GOAL GOAL

IMPLEMENTATION IMPLEMENTATION –

– EXISTING WORK EXISTING WORK

 Previous work from Francis NAHM:

 List of AntiPatterns for each version of the Argouml project (APs example : ComplexClass, LongMethod, LongParameterList)

IMPLEMENTATION IMPLEMENTATION –

– COLLECT COLLECT

 Collect information about the Argouml project:

• SVN log

IMPLEMENTATION IMPLEMENTATION –

– WHAT IS INTERESTING IN WHAT IS INTERESTING IN « « SVN LOG SVN LOG » »

IMPLEMENTATION IMPLEMENTATION –

– KEEP INTERESTING INFORMATION KEEP INTERESTING INFORMATION

• Get the list of contributors
• Get the date of commits
• Get the files/classes that had been modified

IMPLEMENTATION IMPLEMENTATION –

– EVALUATE MAJOR CONTRIBUTOR RATE EVALUATE MAJOR CONTRIBUTOR RATE

• 3rd quartile of all contributors statistics on each classes : 71%

Major contributor: A developer who has made changes to a component and whose

• wnership is at or above X% is a major contributor to the component and a commit

from such a developer is a major contribution.

IMPLEMENTATION IMPLEMENTATION –

– ADD INFORMATION OF MC ON EACH VERSION ADD INFORMATION OF MC ON EACH VERSION

• Know the kind of contributor for each version on each class.
• Add it beside the number of AntiPatterns on each version of each class.

IMPLEMENTATION IMPLEMENTATION –

– WHAT THE CSV LOOKS LIKE WHAT THE CSV LOOKS LIKE

IMPLEMENTATION IMPLEMENTATION –

– METHOD TO ESTIMATE THE EVOLUTION OF A CLASS METHOD TO ESTIMATE THE EVOLUTION OF A CLASS List of the occurrence of AntiPatterns for each class. Example: [5, 3, 4, 4, 1, 2, 5] [0]: A-A-A-A-A-S [1]: D-D-A-A-D [2]: S-A-A-D [3]: A-A-D [4]: D-D [5]: D A = 11 ; D = 8 ; S = 2

• A > D > S  This class is considered to have a global amelioration tendency

IMPLEMENTATION IMPLEMENTATION –

– DIFFERENT CATEGORIES OF LIST DIFFERENT CATEGORIES OF LIST

• Classes with only Major Contributor (MC) on each version of the project.
• Classes without any MC.
• Classes with a MC, only on the first version.
• Classes with a developer who becomes MC after few versions without any.
• Classes where there is no longer MC after few versions with a MC.

RESULTS RESULTS

Only MC No MC Only MC on the 1st version Become MC No longer MC Stable 58% 73,63% 74,40% 87,13% 79,18% Amelioration 24% 11,55% 7,76% 1,98% 14,46% Degradation 18% 14,82% 20,84% 10,89% 6,36%

CONCLUSION CONCLUSION

• Linus Law. “Given a large enough developers, almost every problem will be

characterized quickly and the fix will be obvious to someone“

• AntiPatterns have the same characteristics of Bugs correlate with
• wnership.
• Of course, this work should be reproduced on other projects.

PERSONAL EXPERIENCE PERSONAL EXPERIENCE

• Lab experience
• Met new people
• Learnt Python language (enjoyed coding for once)
• Not sure I would be a good researcher ^^