Software Test Summary (6)

The previous section summarizes the objectives, tasks, and other relevant content of the software testing layer. Next, we will summarize the typical software testing methods, namely black box testing and white box testing. The black box test provides classical analysis methods such as equivalence classification, Boundary Value Analysis, error inference, and cause/effect analysis. This section describes the equivalence classification in the black box test, also known as equivalence allocation or equivalence division, that is, the process of reducing too many (unlimited) test cases to a small range of processes that are equally effective.

Any test case in the valid equivalence class can represent other test cases in the same equivalence class. That is, if a test case is selected from an equivalence classProgramCan reasonably think that other test cases in the program will not discover program defects. Each invalid equivalence class in the invalid equivalence class must use at least one test case, otherwise, a type of error may be missed.

The division of equivalence classes has its own general steps. Next we will explain the specific steps of the division of equivalence classes in a specific example.

Specific problem: a software development company needs to expand the number of candidates between the ages of 20 (born before January 1, November 1992) and 35 (born after January 1, November 1977, if the date of birth is not within the above range, the interview will be rejected and "Age unqualified" will be displayed. Use the equivalence classification method to design a test case for this program function.

Step 1: Divide equivalence classes.It is stipulated that the date of birth is represented by six digits, the first four digits represent the year, and the last two digits represent the month. The following three valid equivalence classes and seven invalid equivalence classes are given, as shown in the following table:

 

 Step 2: design test cases for effective equivalence classes.Before designing a valid equivalence test case, it is best to first number all the equivalence classes, for example, and then design the test case according to the number so that it can overwrite the existing ones as much as possible, the following table shows the test cases:

Share a test case with several equivalence classes to reduce the number of tests, which is advantageous but has no disadvantage.

Step 3: design at least one test case for each invalid equivalence class.In this example, there are seven invalid equivalence classes. At least seven test cases are designed. If less test cases are designed, omissions may occur. The following is an invalid test case.

Even if the equivalence class division of this program is basically completed, pay attention to the general steps of Division during learning. When selecting a test case, you should also carefully consider whether it is in the equivalence class to be tested.

 

The division of equivalence classes is a typical black box testing method and a very practical and important testing method. As a qualified tester, it should have the basic ability to divide equivalence classes and design reasonable test cases for them.

 

Okay. This section ends. The next lecture will summarize another classic method of black box testing-Boundary Value Analysis! Thank you!