Mocks in the project

[Aurelien9Code]

Handling circular dependency

If you check the implementation of MockEvent, MockUser, and MockAssociation, you will see that:

• MockEvent implements mock data structures related to event details, including a list of MockUser instances as participants and organizers, and references to MockAssociation instances for tagged associations.
• MockUser implements user-related mock data, such as their joined and saved MockEvent instances, as well as their associated MockAssociation instances.
• MockAssociation implements association mock data, which includes a list of MockUser instances as members and references to the events they organize or tag.

These interconnected references can lead to a situation known as circular dependency, where creating an instance of one mock requires the instantiation of others, potentially leading to an infinite loop or stack overflow during test execution.

Example :

• Suppose MockUser.createMockUser() is called. This function, by default, generates followedAssociations and joinedAssociations using MockAssociation.createAllMockAssociations().
• Now, when MockAssociation.createAllMockAssociations() is executed, it calls MockAssociation.createMockAssociation(), which includes a list of members created by calling MockUser.createAllMockUsers().
• Similarly, when MockEvent.createAllMockEvents() is called, it might include users (as organizers or participants) and tagged associations created by MockAssociation.

Because each mock class depends on others to generate its full structure, calling one mock generation function can indirectly trigger the instantiation of others, creating a loop:

• MockUser.createMockUser() → calls MockAssociation.createAllMockAssociations()
• MockAssociation.createMockAssociation() → calls MockUser.createAllMockUsers()
• MockUser.createMockUser() calls MockEvent.createAllMockEvents(), which includes MockAssociation references

This cycle can keep repeating, leading to an infinite loop or a stack overflow error when trying to create the mock data.

To prevent circular dependency:

Conditional flags such as associationDependency and eventDependency are used in the mock creation methods. For example, MockUser.createMockUser() uses these flags to decide whether to create actual associations or events or to leave them as empty lists.

By allowing references to be left out or simplified when dependencies are true, the data generation avoids deep nesting loops.