After 3 years of testing experience, do you know the state transition method for use case design?

1、 Concept

The state transition method mainly focuses on testing the correctness of state transition . For a finite state machine , Test to verify whether it can produce the required state change under the given conditions , Are there unreachable states and illegal States , Whether it is possible to produce illegal state transfer, etc . By constructing events that can lead to state migration , To test the transition between States .

2、 Range of application

The idea of state transition method is to provide the idea of testing multiple state transitions . This method is suitable for the case that there are many functional states , It is necessary to test the transition of various states , And these state transition tests are easy to be missed in practical work . Like the player 、 Remote control buttons, etc .

3、 Steps of state transition method

• Analyze requirements , Sort through all the statuses ;

• Draw a state transition diagram ;

• List status - Event table ;

• Get the state transition tree ( Test path );

• Get the test cases according to the state transition tree

4、 Case study ：

demand ： Through a ticketing system , Customers can buy train tickets in advance , Go somewhere .

1. The user logs in to the ticketing system , Choose the place of departure 、 Destination 、 Departure date , Select a train number and click ” booking “, And fill in the information of the Booker , Click submit order ; The current order status is ” Did not pay “;
2. User manually cancels the order , The ticket status is updated to “ Cancelled ”;
3. 45 Not paid within minutes , The order is cancelled automatically , Ticket status is “ Cancelled ”;
4. The user pays the ticket , The ticket status changes to “ Paid ”;
5. When the user arrives at the station, he can pick up the ticket through the automatic ticket machine or the ticket window , Ticket status is “ Tickets have been issued ”;
6. Half an hour before driving , The signature can be changed , The change was successful , Ticket status is “ The change was successful ”;
7. Tickets have been issued / After boarding the train with the ticket changed , The ticket status changes to “ Already used ”;
8. Half an hour before driving , Refundable , Refund successful , Ticket status is “ Refund successful ”.

a、 Sort out all the status of the ticket order ：

Did not pay 、 Cancelled 、 Paid 、 Tickets have been issued 、 Refund successful 、 The change was successful 、 Already used

b、 Draw a state transition diagram ：

c、 List status - Event table ：

This item is not required , This step can be skipped according to the actual situation , Get the state transition tree directly ;

d、 Get the state transition tree ( Test path )：

Get the test path through the above ：

1. Did not pay –> Cancelled
2. Did not pay –> Paid –> Tickets have been issued –> The change was successful –> Refund successful
3. Did not pay –> Paid –> Tickets have been issued –> The change was successful –> Already used
4. Did not pay –> Paid –> Tickets have been issued –> Refund successful
5. Did not pay –> Paid –> Tickets have been issued –> Already used
6. Did not pay –> Paid –> The change was successful –> Refund successful
7. Did not pay –> Paid –> The change was successful –> Already used
8. Did not pay –> Paid –> Refund successful
9. Did not pay –> Paid –> Already used

e、 Get the test cases according to the state transition tree

Each of the above test paths is 1 Test cases , Perform coverage test on each path . There are multiple event triggers for state transitions , Operations that cover multiple events , such as “ Did not pay –> Cancelled ” This test path , Need to test 2 In this case ：1） The user cancels the ticket order manually 2） exceed 45 Minutes user unpaid , Automatically cancel the ticket order

5、 summary

In practice , For products with complex business processes , When the scenario coverage method cannot be used to design use cases well , The idea of state transition method can be applied , Starting from the various states of the business , And the test coverage is carried out by connecting the switching conditions between these states in series , To ensure high coverage of use cases .

Last ： Send learning resources to

These materials , There are also many recorded video tutorials , For friends who do software testing, it should be the most comprehensive and complete war preparation warehouse , This warehouse also accompanied me through the most difficult journey , I hope it can help you ！ Everything should be done as soon as possible , Especially in the technology industry , We must improve our technical skills . I hope that's helpful ……

Come on! , Tested by ！ If you need to improve planning , Then act , Better on the road than at the starting point .