State Transition

State transition is a black-box testing technique used to test systems that can be modeled as finite state machines. State transition testing involves testing the transitions between different states of the system and the events that cause these transitions. This technique helps to uncover defects related to incorrect state transitions and invalid or missing events.

Syntax

There is no specific syntax for state transition testing. The technique involves creating a model of the system that represents all possible states and transitions between those states, and then defining test cases that cover all possible transitions.

Example

Consider a simple example of state transition testing for an ATM machine. The possible states of the machine are Idle, Card Inserted, PIN Entered, and Amount Entered. The possible events that can trigger state transitions are Card Insertion, Incorrect PIN, Correct PIN, Amount Entry, Withdrawal, and Cancel.

Based on this model, the following test cases can be derived:

1. Test case 1: Insert card → Enter correct PIN → Enter valid amount → Withdraw cash.
2. Test case 2: Insert card → Enter incorrect PIN → Cancel.
3. Test case 3: Insert card → Enter correct PIN → Cancel.
4. Test case 4: Insert card → Cancel.

By testing all possible state transitions and events, this technique can help to identify defects related to incorrect state transitions, missing or invalid events, and other issues that may not be discovered using other testing methods.

Output

The output of state transition testing will be a set of test cases, each of which provides coverage of different possible state transitions and events.

Explanation

In state transition testing, the system is modeled as a finite state machine, with each state representing a different status or configuration of the system, and each transition representing a change from one state to another. Test cases are then defined to cover all possible state transitions and events, to identify any defects related to incorrect state transitions or other issues.

Use

State transition testing is used to test systems that can be modeled as finite state machines, such as software applications, embedded systems, and other complex systems with well-defined states and transitions. This technique is useful for identifying defects related to transitions between different states of the system and the events that cause these transitions.

Important Points

• State transition testing is a black-box technique, meaning that it focuses on testing the external behavior of the system without looking into the underlying code or implementation.
• The success of state transition testing depends on the accuracy of the model used to represent the system and all possible state transitions and events.
• When performing state transition testing, it is important to ensure that all possible state transitions and events are covered and that the test cases are designed to identify defects related to incorrect state transitions or missing or invalid events.

Summary

State transition testing is a black-box testing technique used to test systems that can be modeled as finite state machines. The technique involves creating a model of the system that represents all possible states and transitions between those states, and then defining test cases that cover all possible state transitions and events. This technique is useful for identifying defects related to transitions between different states of the system and the events that cause these transitions. It is important to ensure that all possible state transitions and events are covered and that the test cases are designed to identify defects related to incorrect state transitions or missing or invalid events.