Using Class Interfaces and Mock Objects to Unit Test Aspects

82 Pages·2016·0.47 MB·English

Nova Southeastern University
NSUWorks
CEC Theses and Dissertations College of Engineering and Computing
2014
Using Class Interfaces and Mock Objects to Unit
Test Aspects
Michael Bryan Snider
Nova Southeastern University,[email protected]
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Michael Bryan Snider. 2014.Using Class Interfaces and Mock Objects to Unit Test Aspects.Doctoral dissertation. Nova Southeastern
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Using Class Interfaces and
Mock Objects to Unit Test Aspects

by

Michael Bryan Snider

A dissertation submitted in partial fulfillment of the requirements
for the degree of Doctor of Philosophy
in
Computer Science

Graduate School of Computer and Information Sciences
Nova Southeastern University

2014
We hereby certify that this dissertation, submitted by Michael Snider, conforms to acceptable
standards and is fully adequate in scope and quality to fulfill the dissertation requirements
for the degree of Doctor of Philosophy.

_____________________________________________ ________________
Francisco J. Mitropoulos, Ph.D. Date
Chairperson of Dissertation Committee

_____________________________________________ ________________
Sumitra Mukherjee, Ph.D. Date
Dissertation Committee Member

_____________________________________________ ________________
Michael J. Laszlo, Ph.D. Date
Dissertation Committee Member

Approved:

_____________________________________________ ________________
Eric S. Ackerman, Ph.D. Date
Dean, Graduate School of Computer and Information Sciences

Graduate School of Computer and Information Sciences
Nova Southeastern University

2014
An Abstract of a dissertation submitted to Nova Southeastern University in Partial
Fulfillment of the Requirements for the Degree of Doctor of Philosophy

Using Class Interfaces and Mock Objects to Unit Test Aspects

by
Michael B. Snider
May 2014

Aspect oriented programming (AOP) has garnered a great deal of research interest in the
past decade. The research has centered on the ability to implement aspects and to
identify cross-cutting concerns in existing software. Little work has been done on the
ability to test software that is created using AOP constructs.

In object oriented programming (OOP) class objects are individual units of code that
encapsulate the desired functionality of each object. AOP is an attempt to handle the
cross-cutting concerns that represent functionality needed by a class, but is not specific to
that class. The cross-cutting functionality is implemented in AOP by using a class-like
structure, the aspect. Aspects do not have their own context and as such are dependent
upon other objects for their context. By not having their own context it is difficult to test
the functionality of aspects. This study investigated the effectiveness of using class
interfaces and mock objects to unit test aspects. This was accomplished by having the
mock object inherit from the same interface as the base code, so that the mock object
could be swapped in for the aspect.
Acknowledgements

This dissertation would not have been possible without the support and understanding
of many individuals.

I would like to start by thanking my wife Sharon, if it were not for her loving support
this would not have been possible. She put up with all of the hours of studying and
countless trips to Florida that have allowed me to reach this achievement. I also wish to
dedicate this work to my daughters Alexa and Madelyne who continually pushed me to
keep going by asking when I was going to get done and by telling everyone that I was
working on my doctorate.

Next I wish to thank Dr. Frank Mitropoulos. When I started my dissertation I was a
ship lost at sea. Through his guidance I was able to identify a topic of research. He
continued to guide me and advice me so that I continued to make steady progress until
reaching the end. I would also like to thank my committee members Dr. Laszlo and Dr.
Mukherjee.

I wish to thank my father, Bryan William Snider, for his support and faith in me. He
was always there when I needed him no matter where I was or what the need. While he
did not get to see me finish this project he always knew that I would.

Finally I would like to mention my Nova Southeastern doctoral colleagues and study
group. The individuals in this group were there for me providing support and
encouragement during course work and the dissertation process. I would particularly like
to mention Dr. Raymond Halper for being a friend and study partner during the majority
of my course work and Dr. Ron Krawitz for continually providing help and support to
keep me going during the dissertation process.
Table of Contents

Abstract iii
List of Figures vii
List of Tables viii

Chapters

1. Introduction 1
Background 1
Problem Statement 3
Goal 13
Research Questions 13
Relevance and Significance 14
Barriers and Issues 16
Limitations 17
Definitions of Terms 18
Summary 18

2. Review of Literature 20
Unit Testing 20
Data-flow Based Unit Testing 20
State Based Testing 25
Joinpoint Testing 27
Unit Testing of Aspects 29

3. Methodology 34
Research Methods 34
Test Criteria 36
Implementation Strategy 39
Procedures 46
Resource requirements 54

4. Results 55
Analysis 55
Summary of Results 58
How many aspect joinpoint types 60
Is a class interface beneficial 61
Can mock objects supply aspect context 61
Summary 62

5. Conclusions 63
Implications 63
Recommendations 64
v
Summary 65

Reference 71

vi
List of Figures
Figures
1. AOP Weaving Process 2
2. Testing with a stub 6
3. Testing with a mock object 7
4. Interface example 10
5. Stub versus mock 11
6. A stub 12
7. A mock 12
8. Example of an ASM 26
9. Unit test account Id updated 42
10. Person class assigned Id by advice 43
11. Unit test customer class 45
12. Class interface 46
13. Account class in application inheriting interface 48
14. Aspect to validate account class 49
15. Mock account class in test project 51
16. Unit test before aspect weaving 52
17. Unit test after aspect weaving 53
18. Interface usage in an aspect 60

vii
List of Tables
Tables
1. Overview of AspectJ programs evaluated 41
2. Insertion coverage 56
3. Code coverage 57
4. Time comparison 58

viii
1

Chapter 1
Introduction

Background
Aspect Oriented Programming (AOP) was first introduced by Gregor Kickzales in
1996 (Haque, 2011). It was not proposed as a replacement to Object Oriented
Programming (OOP), but as an enhancement. AOP is a methodology that deals with the
problem of cross-cutting concerns found within a software application (Lemos, Ferrari,
Masiero, & Lopes, 2006). In OOP classes are created to represent functional objects that
are specified within the design requirements. However, there exist requirements that
cannot be confined to a single object and do not represent needed functionality of that
object. When a requirement is not a core concern of a class or method and that concern
is needed in numerous places it is considered to be a cross-cutting concern (Monteiro &
Aguiar, 2007). As an example, logging of actions within a method is typically a cross-
cutting concern. Within the method, logging is not a core concern, but it is a requirement
of the application that actions are to be logged. The logging takes place within numerous
methods within the application, but the concern of logging is a functional requirement of
the application.