Home > Articles > Software Development & Management > Object Technology

Introduction to Testing Object-Oriented Software

Testing object-oriented software is different from testing procedural software. This introduction to the book, The Practical Guide to Testing Object-Oriented Software, explains the authors' philosophies behind object-oriented software testing.
Like this article? We recommend

Testing software well has always been challenging, but the process is fairly well understood. Some combination of unit testing, integration testing, system testing, regression testing, and acceptance testing will help to deliver usable systems.

We wanted to write this book because most people seem to believe that testing object-oriented software is not much different from testing procedural software. While many of the general approaches and techniques for testing are the same or can be adapted from traditional testing approaches and techniques, our experience and our research has demonstrated that some things are different and present new challenges. At the same time, well-designed object-oriented software developed as part of an incremental process provides opportunities for improvements over traditional testing processes.

Object-oriented programming language features of inheritance and polymorphism present new technical challenges to testers. We describe solutions for many of these challenges. In this book, we describe processes and techniques for testing object-oriented software effectively during all phases of a development effort. Our approach to testing software is quite comprehensive and one that we believe software development organizations should undertake. At the same time, we realize that resources available for testing are limited and that there are many effective ways to develop software, so we think it is reasonable to pick and choose among the techniques we present in this book.

The adoption of object-oriented technologies brings changes not only in the programming languages we use but in most aspects of software development. We use incremental development processes, refocus and use new notations for analysis and design, and utilize new programming language features. The changes promise to make software more maintainable, reusable, flexible, and so on. We have written this book because changes in the way we develop software produces changes in the way we test software, from both managerial and technical perspectives. The following changes provide opportunities for improving the testing process:

  • We have an opportunity to change attitudes toward testing. In many environments, managers and developers view testing as a necessary evil. Testing that needs to be done by the developers themselves interrupts code production. Reviews, code inspections, and writing unit test drivers take time and money. Testing processes imposed on the developers for the most part just get in the way of coding. However, if we can make everyone appreciate that testing contributes to developing the right software from the start, and that it can actually be used to measure progress and keep development on track, then we can build even better software.

  • We have an opportunity to change where testing fits into a development process. Almost everyone recognizes that the sooner problems are found, the cheaper they are to fix. Unit testing and integration testing uncover problems, but don't usually start until coding has started. System testing is typically done near the end of a development effort or perhaps at certain planned milestones. System testing is treated as a way to see how well the developers did in meeting requirements. Of course, this is a wrong approach. Decisions about how much testing is adequate, when it should be performed, and who should do it should be made only in the context of a well-considered testing strategy that works with the project's software development process. We will show how testing activities can begin early. We will show how testing and development activities can be intertwined and how each can contribute to a successful outcome of the other.

  • We have an opportunity to use new technology to do the testing. Just as object-oriented technologies have benefits for production software, they also can realize benefits in test software. We will show how you can test object-oriented analysis and design models, and how you can use object-oriented programming techniques to develop unit test drivers and reduce the coding necessary to test software components.

Who Should Read This Book?

We have written this book for

  • Programmers who already work in testing software, but want to know more about testing object-oriented software.

  • Managers who are responsible for software development and who would like to know how and where testing fits into a plan.

  • Developers who are responsible for testing the software they produce and who should take testing issues into consideration during the analysis, design, and coding activities.

With such a wide audience, we struggled with the level of detail we needed to include about object-oriented development and testing—the basic concepts associated with software testing, object-oriented programming, and the Unified Modeling Language (UML) to express analysis and design results. We decided to provide brief overviews of these topic areas—what we consider the minimum a reader needs to know to make sense of what we have to say. When we need to resort to code, we use C++ and Java. The approaches and techniques we present apply to all object-oriented programs, not just to those written in C++ and Java.

We have assumed the following software-development scenario, which we consider to be ideal:

  • The process must be incremental, with iterations that occur within each increment.

  • The models expressed in UML must be available.

  • The software design must be in accordance with good design principles with respect to the use of inheritance, data hiding, abstraction, low coupling, and high cohesion.

However, we realize that most organizations have their own processes and notations. Consequently, our focus is primarily on principles and techniques.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020