What are the test case design methods?

In fact, the design method of test cases is mainly 7 The big way ：

Equivalence class division , The boundary value , Scene method , Decision table , Cause and effect diagram , Wrong inference , Orthogonal test method .

Many people just know these methods , Each method combined immediately confused .

Before trying to connect these methods , Let's first look at the problems to be solved by each method .

The emergence of equivalence class partition , Is to make testing possible .

for instance , For example, let's test the mobile phone number input box , If there is no equivalence class partition , So is it necessary to enumerate all the situations once .

At that time, if there was equivalence class division , We can at least classify them .

For example, mobile phone numbers can be divided into valid and invalid , And invalid length can be divided into invalid length , Invalid rule , The input information is not standardized and so on .

After that, after the classification of equivalence classes is completed , The next step is to select the boundary points of the classification boundary , Each boundary value is the boundary point generated after the equivalence class division is completed .

So the boundary value is actually looking for errors at the edge of the equivalence class .

Let's talk about the end scene , A lot of times , We're testing all the software , So when combing the business process , Will use the scene method , Sort out the normal flow with the scene method , Alternative streams , After that, the equivalence class division and boundary value of each flow are refined .

The decision table is used when there is a correlation between input and output , Will sort out the related parts of the business using the judgment table , Combined with each item of the decision table, do the test of refining the boundary value of the equivalent class .

Cause and effect diagrams are less commonly used , The cause and effect diagram itself is actually to get the judgment table . As for error inference , In the process of testing, we often , Combined with the actual situation of the software , Make targeted guesses about where there will be problems , Targeted design use cases .

Last , Orthogonal test , Mainly in the face of multiple factors , When it comes to horizontal relationships , Will use a small amount of instead of comprehensive .

summary ：

Test methods mainly include equivalence classes 、 The boundary value 、 Scene method 、 Decision table 、 Cause and effect diagram 、 Wrong inference 、 Orthogonal test method , First, when you get the requirements document , I will first use the scenario method to sort out the basic flow and alternative flow of the software , Then combine the equivalence class 、 Boundary value analysis test case ; When there is a corresponding relationship between input and output, I will draw the decision table first , Then combine the equivalence class 、 Boundary value analysis ; Of course, there are those very complex , Examples of vending machines mentioned online , I'll sort out the judgment table with the cause and effect diagram first . There is also the ability to accumulate knowledge about software errors based on your own knowledge , Use error inference to test , Finally, there is a less commonly used orthogonal test method , It is mainly used for horizontal relationship , When the project is urgent , A test conducted by sampling .