Test Case Design Methodology I (Equivalent Class Division)

Overview of test case design methods (emphasis)

Test data:

1. Equivalent class division method

2. Boundary value analysis method

Test step design:

Cause and effect diagram method

Decision table method

Scenario method

Orthogonal experiment method

Function diagram method

Test case design:

Test data:

1. Equivalent class division method

2. p>

Equivalent Class Division (emphasis)

1. Principle of Equivalent Class Division Method

Divide the input domain of the program into a number of parts, and then select a small number of representative data from each part to be used as test cases

? The representative data in each class is equivalent in testing to the other values in that class, and if one example in a class finds an error, the other examples in that equivalence class will find the same error.

? Conversely, if one example in a class does not find an error, other examples in this class will not find an error

For example:

The input rule for the password input box is 8-16 bit characters

Designing the input data item in the test case

Up to 8 (excluding 8) characters

Input 7 bits

Input 6 bits

Input 5 bits

...

Enter 0 bits

Between 8 and 16 bits

Enter 8 bits

....

Enter 13 bits

....

Input 16 bits

Above 16 bits (excluding 16 bits)

Input 17 bits

Input 18 bits

....

Enter 25 bits

...

Enter 100 bits

Principles for determining equivalence classes (emphasis added)

? 1. One valid equivalence class and two invalid equivalence classes can be established if the input condition specifies a range of values or a number of values

2. One valid equivalence class and one invalid equivalence class can be established if the input condition specifies a set of input values or specifies a "how it must be done"

? p> ? 3. In the case where the input condition is a Boolean quantity, a valid equivalence class and an invalid equivalence class can be established

4. In the case where a set of values for the input data (assuming n) is specified and the program has to deal with each of the input values separately, n valid equivalence classes and one invalid equivalence class can be established

5. In the case of rules that must be obeyed by the input data, a valid equivalence class (one valid equivalence class) can be established. A valid equivalence class (in accordance with the rules) and a number of invalid equivalence classes (in violation of the rules from different perspectives)

6. In the case of knowing that the elements of the divided equivalence classes are processed in different ways in the program, the equivalence class should be further divided into smaller equivalence classes

Equivalence class division (emphasis)

1. Division of the equivalence classes and the equivalence class list

2.

2. Determine test cases

? Specify a unique number for each equivalence class

? Design a new test case that covers as many valid equivalence classes as possible that are not already covered. Repeat this step so that all valid equivalence classes are covered by the test case

? Design a new test case that covers only one invalid equivalent class. Repeat this step so that all invalid equivalence classes are covered

Note: Do not repeat, do not miss

For example: Baidu registration username rules are:

Can not be modified after the setup, Chinese and English can be used, up to 14 English or 7 Chinese characters;

(the default is not null, no repetition)

Using Equivalence Classes for Web Mail Registration Division method to design the input data items for test cases