LES | DI | PUC-Rio - Brasil OPUS Research Group

Refactoring Impact on Software Maintainability

Diego Cedrim

–Martin Fowler

“A change made to the internal structure of software to make it easier to understand and

cheaper to modify without changing its observable behavior.”

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–Kent Beck

“A code smell is a surface indication that usually corresponds to a deeper problem in the

system.”

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Refactoring is the process of improving the structure of a program without changing its behavior

Code smells can be used as an indication of relevant structural problems

Refactoring can be used to remove code smells

Software maintainability is increased when code smells are removed

Refactoring / Code Smells

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Do refactoring activities improve software maintainability after the

transformations?

Dataset: 13 versions of the version histories of OODT, Heath Watcher and Mobile Media systems

Method: for each pair of versions, we compute the number of anomalies before and after each refactoring

Analysis: observe the behavior of increasing or decreasing number of anomalies

Used Solving Method

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Code Smells Number After Refactoring

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Increased Decreased Unchanged

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910

Inspiration

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RQ1: Do refactoring activities improve software maintainability after the transformations?

RQ2: Is there any pattern between refactoring types and created/removed code smells?

Research Questions

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Ref-Finder: Refactoring Activities Collection

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PMD: Code smell detector

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Target: GitHub

New Solving Method

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Ref-Finder run as a Eclipse plugin

How to run it outside of Eclipse?

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False positives/negatives

Unsolved Problems

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LES | DI | PUC-Rio - Brasil OPUS Research Group

Refactoring Impact on Software Maintainability

Diego Cedrim