Add unit tests

[htrgouvea]

Context:

The integration of unit testing is a critical step in ensuring the reliability, resilience, and quality of our codebase. By performing targeted tests on individual components, we can detect bugs early, enhance code stability, and provide a solid foundation for seamless collaboration and accelerated development.

In the context of Nozaki's code, automated unit tests will help verify the isolated functionality of each component, safeguarding against regressions and building confidence during future changes and refactoring. These tests also serve as living documentation, fostering improved teamwork and better understanding of the code.

What is needed to do:

Identify the main components and functions of the project to create test cases.
Implement tests that validate critical scenarios and ensure comprehensive coverage.
Select an appropriate testing framework and integrate it into the CI/CD pipeline.

Definition of Done:

All key modules have a minimum test coverage of 80%.
None of the implemented tests fail in the CI pipeline.
The test documentation has been updated to reflect the added unit tests.