Software testing and quality learning notes 1 --- black box testing

1. Black box testing -- Division of equivalence class
2. What is the equivalence class division method
Equivalence class It refers to a subset of an input field . Equivalence classes are divided into Effective equivalence class （ reasonable 、 meaningful , Function and performance ）、 nothing Efficient equivalence class （ Unjustified 、 Meaningless , exception handling ）.
Effective equivalence classes and invalid equivalence classes need to be considered when testing cases .
Division of equivalence class ： Divide all possible input data into several parts ( A subset of ）, Then from each subset Select a few representative data as test cases .
3. How to divide ？
3.1---- Types of equivalent classes
（1） Divided by bilateral interval （ Specifies the Value range or number of values , This can determine a valid equivalence class and two invalid equivalence classes ） 
（2） According to different values （ Specifies the A set of values （ Assume n individual ）, And the program should process each input value separately , Determinable n Valid equivalence class and invalid equivalence class ）
（3） Divided by unilateral interval ( The input condition specifies the set of input values , In this case, an effective equivalence class and an invalid equivalence class can be established )
（4） According to the restrictions / Rule Division ( It specifies the rules or restrictions that must be observed by the input data , A valid equivalence class can be determined （ Conform to the rules ） And several invalid equivalent classes （ From different angles

--------- Degrees violate the rules ）.
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1. Boundary value analysis - Black box testing
A black box test method for testing input or output boundary values . As a supplement to the equivalence class division method .
2. Boundary point
Boundary points are relative to input equivalence classes and output equivalence classes , Slightly higher than 、 Slightly below Some specific cases of its boundary value
3. The difference between boundary value analysis method and equivalence classification method
Division of equivalence class ： From an equivalent class Optional In one as test data
Boundary value analysis ： Every The boundary is targeted Select test data , For input data and output data
Be careful ： How to select test data by boundary value analysis （ See the picture for details ）

example ： The specification of the procedure stipulates :“ The weight is 10 Kg to 50 kg Messages in range , The test data should take 10 And 50, You should also take 10.01,   49.99,    9.99   And 50.01 etc. .
Analysis specifications , Find out other possible boundary conditions
for example , Special boundary values : The default value is 、 Null value 、 Space 、 zero 、 Invalid data, etc .
4. Boundary condition test case design method
The boundary based method is implemented according to the definition domain , Four technologies .
General boundary value condition test ： For one n Variable function , The number of test cases generated by this method is 4n+1 individual
Robustness boundary condition test ： For one n Variable function , The number of test cases generated by this method is 6n+1 individual
Worst case test ： For one n Variable function , The number of test cases generated by this method is 5^n individual .
Robust worst case testing ： For one n Variable function , The number of test cases generated by this method is 7^n individual .

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1、 Decision table method - Black box testing
Premise ： The equivalence division method and boundary value analysis method are more suitable for the case where the input variables or input conditions are independent of each other , But when input variables or input conditions are interdependent 、 When they restrict each other , It is difficult to describe using the equivalent class division method and boundary value analysis method , The test effect is also difficult to guarantee .
2. Determine the composition of the table       The rules —Rule
Condition stake — List all the conditions of the problem .Condition Stub
Condition item A condition given for the condition pile , List all possible values Condition Entity
Action post — List possible actions specified in the problem .Action Stub
Action items — It points out the actions to be taken when each group of condition items takes value .Action Entity
3. The simplification of the decision table mainly includes : Rule merge and rule include
4. The establishment steps of decision table
List all condition piles and action piles -- Determine the number of rules -- Fill in the conditions -- Fill in the action items -- Simplify the decision table