| cc2e.com/2261 Contents Role of Developer Testing in Software Quality page 500 Recommended Approach to Developer Testing page 503 Bag of Testing Tricks page 505 Typical Errors page 517 Test-Support Tools page 523 Improving Your Testing page 528 Keeping Test Records page 529
Related Topics The software-quality landscape: Chapter 20 Collaborative construction practices: Chapter 21 Debugging: Chapter 23 Integration: Chapter 29 Prerequisites to construction: Chapter 3
Testing is the most popular quality-improvement activity a practice supported by a wealth of industrial and academic research and by commercial experience. Software is tested in numerous ways, some of which are typically performed by developers and some of which are more commonly performed by specialized test personnel: Unit testing is the execution of a complete class, routine, or small program that has been written by a single programmer or team of programmers, which is tested in isolation from the more complete system. Component testing is the execution of a class, package, small program, or other program element that involves the work of multiple programmers or programming teams, which is tested in isolation from the more complete system. Integration testing is the combined execution of two or more classes, packages, components, or subsystems that have been created by multiple programmers or programming teams. This kind of testing typically starts as soon as there are two classes to test and continues until the entire system is complete. Regression testing is the repetition of previously executed test cases for the purpose of finding defects in software that previously passed the same set of tests. System testing is the execution of the software in its final configuration, including integration with other software and hardware systems. It tests for security, performance, resource loss, timing problems, and other issues that can't be tested at lower levels of integration.
In this chapter, "testing" refers to testing by the developer, which typically consists of unit tests, component tests, and integration tests but can sometimes include regression tests and system tests. Numerous additional kinds of testing are performed by specialized test personnel and are rarely performed by developers, including beta tests, customer-acceptance tests, performance tests, configuration tests, platform tests, stress tests, usability tests, and so on. These kinds of testing are not discussed further in this chapter.  | Testing is usually broken into two broad categories: black-box testing and white-box (or glass-box) testing. "Black-box testing" refers to tests in which the tester cannot see the inner workings of the item being tested. This obviously does not apply when you test code that you have written! "White-box testing" refers to tests in which the tester is aware of the inner workings of the item being tested. This is the kind of testing that you as a developer use to test your own code. Both black-box and white-box testing have strengths and weaknesses; this chapter focuses on white-box testing because that's the kind of testing that developers perform. |
Some programmers use the terms "testing" and "debugging" interchangeably, but careful programmers distinguish between the two activities. Testing is a means of detecting errors. Debugging is a means of diagnosing and correcting the root causes of errors that have already been detected. This chapter deals exclusively with error detection. Error correction is discussed in detail in Chapter 23, "Debugging." The whole topic of testing is much larger than the subject of testing during construction. System testing, stress testing, black-box testing, and other topics for test specialists are discussed in the "Additional Resources" section at the end of the chapter. |
