Stateful Testing

This section aims to explain how the stateful testing of Kea is designed and implemented.

Functional Description and Design

The Bundle class is the core class of stateful testing. It is primarily responsible for recording the combinations of related states and operations of multiple groups of different types of data, used to test the behavior of the system under different states. This class provides complete member methods for CRUD operations of the state. The main methods included in Bundle are:

• Determine whether a new state needs to be added based on the current status of the data type (singleton pattern).

• CRUD operations on the state of a certain type of data.

• Randomly generate status text values of specified length.

• Randomly retrieve a state of a certain type of data.

Composition of the Bundle Class

Implementation of data structures in the Bundle class

1. _bundle_

   _bundle_ is a class variable of Bundle, which serves as a state record library for various types of data in stateful testing, used to store application states for easy manipulation of the states. Each data item is stored as a <string, Bundle> key-value pair.

2. data_name

   data_name is of string type and stores the name of a type of data.

3. data_value

   data_value is of list type and stores all states of the data of that type.

Note

To facilitate reader understanding, the code snippets provided in this article are simplified versions that abstract and display only the core processes, and the actual code may not fully align with the simplified reference code.

Implementation of functional methods in the Bundle class

Singleton Pattern Method

1. __new__

   Determine whether a Bundle object of the current data type has been instantiated based on the name of the current data type. If it has not been instantiated, instantiate the Bundle object of that type and return it. Otherwise, do not instantiate and return the previously instantiated object.

   Parameters:

   • data_name: The name of the type of data to instantiate.

   Returns:

   • An instance of that type of data.

   def __new__(cls, data_name: str = None):
       if data_name in cls._bundles_:
           return cls._bundles_[data_name]
       else:
           instance = super().__new__(cls)
           cls._bundles_[data_name] = instance
           return instance
   

Member Methods for CRUD Operations on Data States

1. add

   Add a state for the current type of data.

   Parameters:

   • value: The added state value.

   def add(self, value = None):
       if value is None:
           raise ValueError("the value of " + self.data_name + " cannot be None")
       self.data_value.append(value)
   

2. delete

   Delete a state for the current type of data.

   Parameters:

   • value: The state value to be deleted.

   def delete(self, value = None):
       if value is None:
           raise ValueError("the value of " + self.data_name + " cannot be None")
       self.data_value.remove(value)
   

3. update

   Update the state for the current type of data.

   Parameters:

   • value: The old state value to be modified.

   • new_value: The new state value.

   def update(self, value = None, new_value = None):
       if new_value is None:
           raise ValueError("the new name of " + self.data_name + " cannot be None")
       if value is None:
           raise ValueError("the old name of " + self.data_name + " cannot be None")
       try:
           self.data_value.remove(value)
           self.data_value.append(new_value)
       except KeyError:
           print(f"'{value}' is not a object of Bundle.")
   

4. get_all_data

   Retrieve all states of that type of data.

   Returns:

   1. List of States

   def get_all_data(self):
       return self.data_value
   

Member Method to Randomly Generate Status Text

1. get_random_text

   Randomly generate status text values of specified length.

   Parameters:

   • value_max_len: The maximum length of the required status text value.

   Returns:

   1. Valid Status Text Values

   def get_random_text(self, value_max_len = 10):
       text = st.text(alphabet=string.ascii_letters, min_size=1, max_size=value_max_len).example()
       return text
   

Member Method to Randomly Retrieve a State

1. get_random_data

   Randomly retrieve a state of a certain type of data.

   Returns:

   1. A state value of that type of data.

   def get_random_data(self):
       random_item = random.choice(self.data_value)
       return random_item