SOFTWARE TESTING. Yogesh Singh

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3 SOFTWARE TESTING Yogesh Singh

4 CAMBRIDGE UNIVERSITY PRESS Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo, Delhi, Tokyo, Mexico City Cambridge University Press 4381/4, Ansari Road, Daryaganj, Delhi , India Published in the United States of America by Cambridge University Press, New York Information on this title: Yogesh Singh 2012 This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2012 Printed in India at... A catalogue record for this publication is available from the British Library Library of Congress Cataloguing in Publication data Singh, Yogesh, Software testing / Yogesh Singh. p. cm. Includes bibliographical references. Summary: Discusses the concept of Software Testing with real-life case studies and solved examples -- Provided by publisher. ISBN (hardback) 1. Computer software--testing. 2. Computer software--quality control. I. Title QA76.76.T48S '4--dc ISBN Hardback Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate.

5 Contents List of Figures List of Tables Preface Acknowledgements xi xv xxi xxiii 1. Introduction Some Software Failures The Explosion of the Ariane 5 Rocket The Y2K Problem The USA Star-Wars Program Failure of London Ambulance System USS Yorktown Incident Accounting Software Failures Experience of Windows XP Testing Process What is Software Testing? Why Should We Test? Who Should We Do the Testing? What Should We Test? Some Terminologies Program and Software Verification and Validation Fault, Error, Bug and Failure Test, Test Case and Test Suite Deliverables and Milestones Alpha, Beta and Acceptance Testing Quality and Reliability 23

6 iv Contents Testing, Quality Assurance and Quality Control Static and Dynamic Testing Testing and Debugging Limitations of Testing Errors in the Software Requirement and Specification Document Logical Bugs Difficult to Measure the Progress of Testing The V Shaped Software Life Cycle Model Graphical Representation Relationship of Development and Testing Parts 27 Multiple Choice Questions 28 Exercises 34 Further Reading Functional Testing Boundary Value Analysis Robustness Testing Worst-Case Testing Robust Worst-Case Testing Applicability Equivalence Class Testing Creation of Equivalence Classes Applicability Decision Table Based Testing Parts of the Decision Table Limited Entry and Extended Entry Decision Tables Do Not Care Conditions and Rule Count Impossible Conditions Applicability Cause-Effect Graphing Technique Identification of Causes and Effects Design of Cause-Effect Graph Use of Constraints in Cause-Effect Graph Design of Limited Entry Decision Table Writing of Test Cases Applicability 99 Multiple Choice Questions 102 Exercises 105 Further Reading Essentials of Graph Theory What is a Graph? Degree of a Node Regular Graph 113

7 Contents v 3.2 Matrix Representation of Graphs Incidence Matrix Adjacency Matrix Paths and Independent Paths Cycles Connectedness of a Graph Generation of a Graph from Program Program Graphs DD Path Graphs Identification of Independent Paths Cyclomatic Complexity Graph Matrices 150 Multiple Choice Questions 159 Exercises 161 Further Reading Structural Testing Control Flow Testing Statement Coverage Branch Coverage Condition Coverage Path Coverage Data Flow Testing Define/Reference Anomalies Definitions Identification of du and dc Paths Testing Strategies Using du-paths Generation of Test Cases Slice Based Testing Guidelines for Slicing Creation of Program Slices Generation of Test Cases Mutation Testing Mutation and Mutants Mutation Operators Mutation Score 216 Multiple Choice Questions 223 Exercises 226 Further Reading Verification Methods Peer Reviews 231

8 vi Contents Walkthroughs Inspections Applications Software Requirements Specification (SRS) Document Verification Nature of the SRS Document Characteristics and Organization of the SRS Document SRS Document Checklist Software Design Description (SDD) Document Verification Organization of the SDD Document The SDD Document Checklist Source Code Reviews Issues Related to Source Code Reviews Checklist of Source Code Reviews User Documentation Verification Review Process Issues User Documentation Checklist Software Project Audit Relevance Scale Theory and Practice Scale Project Audit and Review Checklist Case Study 257 Multiple Choice Questions 279 Exercises 282 Further Reading Creating Test Cases from Requirements and Use Cases Use Case Diagram and Use Cases Identification of Actors Identification of Use Cases Drawing of Use Case Diagram Writing of Use Case Description Generation of Test Cases from Use Cases Generation of Scenario Diagrams Creation of Use Case Scenario Matrix Identification of Variables in a Use Case Identification of Different Input States of a Variable Design of Test Case Matrix Assigning Actual Values to Variables Guidelines for generating validity checks Data Type Data Range Special Data Conditions Mandatory Data Inputs Domain Specific Checks Strategies for Data Validity Accept Only Known Valid Data 317

9 Contents vii Reject Known Bad Data Sanitize All Data Database Testing 326 Multiple Choice Questions 331 Exercises 333 Further Reading Selection, Minimization and Prioritization of Test Cases for Regression Testing What is Regression Testing? Regression Testing Process Selection of Test Cases Regression Test Cases Selection Select All Test Cases Select Test Cases Randomly Select Modification Traversing Test Cases Reducing the Number of Test Cases Minimization of Test Cases Prioritization of Test Cases Risk Analysis What is Risk? Risk Matrix Code Coverage Prioritization Technique Test Cases Selection Criteria Modification Algorithm Deletion Algorithm 352 Multiple Choice Questions 363 Exercises 364 Further Reading Software Testing Activities Levels of Testing Unit Testing Integration Testing System Testing Acceptance Testing Debugging Why Debugging is so Difficult? Debugging Process Debugging Approaches Debugging Tools Software Testing Tools Static Software Testing Tools 379

10 viii Contents Dynamic Software Testing Tools Process Management Tools Software Test Plan 382 Multiple Choice Questions 383 Exercises 386 Further Reading Object Oriented Testing What is Object Orientation? Classes and Objects Inheritance Messages, Methods, Responsibility, Abstraction Polymorphism Encapsulation What is Object Oriented Testing? What is a Unit? Levels of Testing Path Testing Activity Diagram Calculation of Cyclomatic Complexity Generation of Test Cases State Based Testing What is a State Machine? State Chart Diagram State Transition Tables Generation of Test Cases Class Testing How Should We Test a Class? Issues Related to Class Testing Generating Test Cases 412 Multiple Choice Questions 415 Exercises 417 Further Reading Metrics and Models in Software Testing Software Metrics Measure, Measurement and Metrics Applications Categories of Metrics Product Metrics for Testing Process Metrics for Testing Object Oriented Metrics Used in Testing 423