ARIES: An Eclipse Plug-in To Support Extract Class Refactoring

ARIES: An Eclipse plug-in to Support Extract Class RefactoringGabriele Bavota#, Andrea De Lucia*, Andrian Marcus❊

Rocco Oliveto✢, Fabio Palomba*, Michele Tufano*

*University of Salerno, Italy❊Wayne State University, USA✢University of Molise, Italy

#University of Sannio, Italy

8th Italian Workshop on Eclipse Technologies, Crema19/09/2013

sabato 14 settembre 13

Refactoring Software Systems: why?

Extract Class Refactoring

ARIES: Automated Refactoring In EclipSe

A Graph-theory based method for Extract Class Refactoring

Context

ClassClass

Class

Supporting Extract Class Refactoring in Eclipse


Refactoring Software SystemsContext


CohesionCoupling

W. Stevens, G. Myers, and L. Constantine. Structured Design.

IBM Systems Journal, 13(2): 115 - 139, 1974


Tibor Gyimóthy, Rudolf Ferenc, and István Siket. Empirical validation of object-oriented metrics on open source software for fault prediction. IEEE Transactions on Software Engineering (TSE), 2005.

M. Abbes, F. Khomh, Y.-G. Guéhéneuc, and G. Antoniol. An empirical study of the impact of two antipatterns, blob and spaghetti code, on program comprehension. European Conference on Software Maintenance and Reengineering, CSMR 2011.

L. C. Briand, J. Wüst, J. W. Daly, and V. D. Porter. Exploring the relationship between design measures and software quality in object- oriented systems. Journal of Systems and Software (JSS), 2000.

Restructuring... why?ProducvyCompnsibily# Defect


Refactoring is...“Refactoring is a disciplined technique for restructuring an

existing body of code, improving its non-functional attributes without changing its external behavior.”


BLOB


Splitting a class having many responsibilities into different classes

InputClass C

BLOB

Class C1Output

Class C2

cohesion = 0.2 cohesion = 0.5 cohesion = 0.4



How?

InputClass C

BLOB

Class C1Output

Class C2

cohesion = 0.2 cohesion = 0.5 cohesion = 0.4



ClassClass

Class

A Graph-theory based method for Extract Class Refactoring

G. Bavota, A. De Lucia, A. Marcus, and R. Oliveto.Automating Extract Class Refactoring: an Improved Method and its Evaluation.

Empirical Software Engineering (EMSE), 2013


GRAPH theory-based


GRAPH theory-basedClass C

BLOBmethod-by-methodmatrix construction

m1 m2 ........ mnm1m2........mn

n methods




m1 m2 ........ mnm1m2........mn

SSM CIM CSMStructural Similarity

between MethodsCall-based Interaction

between MethodsConceptual Similarity

between Methods

n methods




m1 m2 ........ mnm1m2........mn

SSM CIM CSMStructural Similarity

between MethodsCall-based Interaction

between MethodsConceptual Similarity

between Methods

n methods

ci,j = wSSM · SSM + wCIM · CIM + wCSM · CSM


GRAPH theory-basedm1 m2 ........ mn

m1m2........mn

method-by-method matrixfiltering and transitive closure

0.8

0.70.5

0.70.6

Chain 1

Chain 2Chain 3


GRAPH theory-basedm1 m2 ........ mn

m1m2........mn

method-by-method matrixfiltering and transitive closure

0.8

0.70.5

0.70.6

Chain 1

Chain 2Chain 3

0.8

0.70.5

0.70.6

Chain 1

Chain 2Chain 3

merging trivialchains

Chain 1

Candidate Class 1

Chain 2Chain 3

Candidate Class 2


Metric basedevaluation


Considered Metrics


Considered Metrics

Lack of Cohesion of Methods (LCOM)The pairs of methods in a class do not sharing any attribute


Considered Metrics

Lack of Cohesion of Methods (LCOM)The pairs of methods in a class do not sharing any attributeConceptual Cohesion of Classes (C3)Semantic similarity between methods of a class


Considered Metrics

Lack of Cohesion of Methods (LCOM)The pairs of methods in a class do not sharing any attributeConceptual Cohesion of Classes (C3)Semantic similarity between methods of a classMessage Passing Coupling (MPC)The number of calls between a pair of classes


Considered Metrics

Lack of Cohesion of Methods (LCOM)

Conceptual Cohesion of Classes (C3)

Message Passing Coupling (MPC)

The pairs of methods in a class do not sharing any attribute

Semantic similarity between methods of a class

The number of calls between a pair of classes


Considered Metrics

+82%Lack of Cohesion of Methods (LCOM)







Considered Metrics

+82%+105%








Considered Metrics

+82%+105%+3%








Evaluation based on historical information


Class1

Class2

Class3

rel1 rel2

Generic Change Refactoring Operation


Class1

Class2

Class3

rel1 rel2

Generic Change Refactoring Operation

Class 1 rel1Class 1 rel2

Rename Field

Class 2 rel1Class 2, Class 3 rel2

Extract Class


System Original Class Extracted Classes

Apache HSQLDB

Database (41) Database (27)

Apache HSQLDB

Database (41)SchemaManager(14)

Apache HSQLDB Select (14) Select (7)Apache HSQLDB Select (14)Result (7)

Apache HSQLDB

UserManager (13) UserManager (10)

Apache HSQLDB

UserManager (13)GranteeManager (3)

ArgoUMLFileGeneratorAdapter (9) FileGeneratorAdapter (3)

ArgoUMLFileGeneratorAdapter (9)

TempFileUtils (6)ArgoUMLImport (10) Import (7)

ArgoUMLImport (10)

ImportCommon (3)

JEdit JEditTextArea (214)JEditTextArea (22)

JEdit JEditTextArea (214) SelectionManager (11)JEdit JEditTextArea (214)TextArea (181)

JFreeChartJFreeChart (24) JFreeChart (16)

JFreeChartJFreeChart (24)

Plot (8)JFreeChartNumberAxis (20) NumberAxis (16)

JFreeChartNumberAxis (20)

ValueAxis (4)

JHotDraw DefaultApplicationModel (14) DefaultApplicationModel (4)JHotDraw DefaultApplicationModel (14)AbstractApplicationModel (10)

XercesXMLDTDValidator (69) XMLDTDValidator (38)

XercesXMLDTDValidator (69)

XMLDTDProcessor (31)XercesXMLSerializer (25) XMLSerializer (12)

XercesXMLSerializer (25)

DOMWriterImpl (13)sabato 14 settembre 13

Class MoJoFMDatabase (41) 97%

Select (14) 83%

UserManager (13) 93%

FileGeneratorAdapter (9) 86%

Import (10) 100%

JEditTextArea (214) 84%

JFreeChart (24) 95%

NumberAxis (20) 94%

DefaultApplicationModel (14) 92%

XMLDTDValidator (69) 88%

XMLSerializer (25) 91%

Average 91%


Developers Evaluation


Subjects50 Master’s students

Meaningfulness of the suggested refactoring operations

Objects17 Blobs used in the metric-based evaluation

What we askedAgreement to the claim: “The proposed refactoring results in a better division of responsibilities”

Five point Likert scale: “1: Strongly disagree; 2: Disagree; 3: Neutral; 4: Agree; 5: Fully agree”


5

4

3

2

1

approach random approach randomGanttProject Xerces


5

4

3

2

1

approach random approach randomGanttProject Xerces

Average Score4.3


More qualitative feedback


Subjects15 Master’s students

Objects11 Blobs refactored by original developers

What we askedWould you split this class?

if YES:i. Why? ii. Would you split the class differently than the provided refactoring solution? Why? iii. Did you find the provided refactoring solution useful as starting point to perform your refactoring? Why?

if NO:i. Why?:


Usefulness of the provided refactoring1. it eases code comprehension; 2. it highlights the main responsibilities implemented in a class; 3. the extracted classes are cohesive.


Usefulness of the provided refactoring1. it eases code comprehension; 2. it highlights the main responsibilities implemented in a class; 3. the extracted classes are cohesive.

“without the refactoring suggestion it would be too difficult to identify the main responsibilities of the classes”


MoJoFM between refactorings performed by students and those by the original

developers

93%sabato 14 settembre 13

DEMO


Conclusions & Future work


...conclusion...

G. Bavota, A. De Lucia, A. Marcus, R. Oliveto, and F. Palomba. Supporting Extract Class Refactoring in Eclipse: The ARIES Project.

In Proceedings of the 34th International Conference on Software Engineering (ICSE 2012), Zurich, Switzerland, 2012. IEEE Press. Formal Tool Demo. pp. 1419-1422


...future work...

implement other refactoring operations,and more sophisticated approaches to detect Blobs

release ARIES asaphttp://www.dmi.unisa.it/people/bavota/www/pages/projects.html

Dec

1


http://www.dmi.unisa.it/people/bavota/www/pages/projects.html








Fabio Palombafabiopalomba13

[email protected]

http://www.linkedin.com/pub/fabio-palomba/4a/542/60

Thank you!Questions and/or comments

ARIES: An Eclipse plug-in to Support Extract Class Refactoring

University of Salerno


mailto:[email protected]

mailto:[email protected]



ARIES: An Eclipse Plug-in To Support Extract Class Refactoring

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