Test theory series - Test Case elements and design methods Part II

2022-04-29 10:13:42

3. Decision table method

`````` background ：
Both the equivalence class division method and the boundary value analysis method focus on the input conditions of a single input , however   Various combinations of input conditions are not considered 、 The mutual restriction between input conditions and output conditions .
Therefore, the decision table method should be used to solve the process of writing test cases in the above cases

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What is the decision table method

`````` The decision table method indicates that there are multiple inputs and multiple outputs ,
And there is a mutual combination relationship between inputs 、  Mutual restriction
There are interdependencies between inputs and outputs

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The four components of the decision table

`````` The judgment table usually consists of four parts
1. Condition stake ： All conditions entered . Lists all inputs to the system , The order of input listed is irrelevant
2. Action post ： All output results . Lists the possible actions the system may take , The order of these operations is not constrained
3. Condition item ： Value of conditional pile . List the values entered for its left column , True and false values in all possible cases
4. Action items ： The value of the action pile . List the actions that should be taken under various values of the input item
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Design steps of decision table

``````1.  Clear requirements
2.  Draw a decision table
2.1、 Define the conditions , Action post
2.2、 Fill in the condition item , Make a full combination of conditions
2.3、 Specify the action items corresponding to each condition combination

3.  Generate test cases , Each rule in the decision table corresponds to a test case
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Application ：

1） There are mutual combinations or constraints between multiple inputs

2） The output depends on the combination of input conditions

Decision table case

`````` The user's mobile phone is down or in arrears , Calls are not allowed .
Draw the decision table as follows
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4. Cause and effect diagram

Cause and effect diagram definition

`````` Cause and effect diagram is to analyze the combination and restriction relationship between conditions by drawing a diagram , And the result of the combination of conditions .
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The core of cause and effect diagram method

`````` because  、  fruit
1、 Cause and effect diagram “ because ”—— reason , Input condition
2、 Cause and effect diagram “ fruit ”—— result , Output results
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The relationship between cause and effect diagram and decision table ：

`````` Causality diagram is the intermediate process of output decision table , Assist in analysis by drawing cause and effect diagram , Output judgment table .
The cause and effect diagram must produce a judgment table , To produce use cases .
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Basic symbols in cause and effect diagram method

`````` Usually used in cause and effect diagrams C Show why , use E Show the result .
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Basic elements of cause and effect diagram ：

`````` Identity ： ·  as long as   reason 1  happen ,  Will produce results 1
Not ：  As long as the reason 1  It doesn't happen   It will produce poor results 1
or ：  There are only a few reasons for one to happen ,  It produces results 1
And ：  Several reasons are satisfied at the same time , Will produce results 1
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The basic steps of causality diagram method

``````1.  Clear requirements
2.  Draw a cause and effect diagram
3.  Convert the cause and effect diagram into a decision table
4.  Generate test cases
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Cause and effect diagram case
If you want to modify the file , The first character entered must be A perhaps B, The second column of characters must be a number , If If the characters in the first column are incorrect, the information is given L, If the characters in the second column are incorrect , Then give the information M demand ：

5. Orthogonal method

Concept of orthogonal method

``````1.  Use the least test cases to obtain the maximum test coverage
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Scope of application

``````1）  When the number of combinations of multiple conditions is huge .
2)  There is a combinatorial relationship between conditions
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The concept of orthogonal table

Use steps of orthogonal arrangement method

``````1.  Clear requirements
2.  List factors and levels
3.  Find the right orthogonal table , Replace numbers .
4.  Convert bit test cases
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Orthogonal table features ：

``````1.  Evenly distributed , 2.  Neat and comparable
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How to select orthogonal table and its practical tools
How to choose the right orthogonal table

6. Flow chart method

Definition ：

`````` Flow method is a method of analyzing the scene by drawing a flow chart
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Applicable scenario ：

`````` When there are complex business scenario analysis
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Test case design steps ：

``````1）  Analyze requirements
2）  According to the demand （ Business relationship ） Draw a flow chart
3）  List the scenarios of the requirements process .
4）  Write test cases according to the flow chart .
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Case study ：

`````` Give the three sides of the user a,b,c,  Judge the shape of the triangle .
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7. Scene method

Scene method definition ：

`````` Simulate user's operation ,  Design test cases from the perspective of users , Consider the combination of multiple functions required .
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The scene method focuses on ：

``````1.  Focus on the combination of multiple functions . That is, focus on whether the process can go through
2.  Don't focus on   details .
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Application ：

`````` Test of system function module .  Smoke testing .
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Two important concepts ：

`````` Basic flow ： Correct operation of the product
Alternative streams ： Wrong operation of the product .
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Scenario method test case steps
、 ```
1. Clear requirements
2. Determine the basic flow and alternative flow
3. Determine the scene according to the basic flow and alternative flow
4. A scenario is a test case

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## 8.  Wrong guess
** Definition ：**
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Error inference refers to the use of intuition and experience to guess the possible types of errors ,
List all possible errors and error prone situations in the program ,
It is a test case design method that experienced testers like to use .

``````** The basic idea ：**
``````

The basic idea is to make a list of possible mistakes or mistakes , Then write test cases according to the list ;
This method is largely based on experience , That is, based on people's analysis of the test results made in the past , Intuitively speculate on the regularity of the revealed defects to find defects

``````** Applicable scenario ：**
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Tight projects and urgent tasks 、 Didn't have enough time , Don't test step by step at this time ;
Based on previous project experience , Find similar modules that have made mistakes before and focus on testing ;
After all normal tests , Through the error inference method, test some modules that have had problems before .

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##  Last ： Summary of test case design method
Usually when determining the test method , There are several reference principles ：
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（1） If there is an input function in a test function , Combination without input , have access to ------- Equivalence class
（2） If there is an input function in a test function , When the input type or range length has a boundary , have access to ----- The boundary value , The most error prone part of development is here
（3） If you test a product , There are multiple inputs , Multiple outputs , Moreover, there is a relationship of mutual combination and mutual restriction between inputs , There are interdependencies between inputs and outputs . Relationships can use ---------- Decision table Cause and effect diagram
（4） For the software of parameter configuration class , The combination of parameters needs to be considered , Get the maximum test coverage with the least test cases , can To use the ------------ Orthogonal method
（5） For the combinational logic test between multiple functions , have access to — Scene method , flow chart . There are many abnormal scenes , Also often miss
（6） use ( ---- Wrong inference ----- )) Then add test cases —— Rely on the experience and wisdom of Test Engineers .

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