[🛠️] Add unit tests (jest)

[TheDanniCraft]

Is your feature request related to a problem? Please describe.
Currently, we don’t have automated tests set up, which makes it harder to ensure the code quality and reliability of new features or bug fixes introduced through Pull Requests (PRs). Manually testing each PR can be time-consuming and error-prone.

Describe the solution you'd like
I propose adding Jest as a testing framework to the project. This will allow us to write unit tests that automatically run each time a new PR is opened. These tests will ensure that the code works as expected and reduces the risk of introducing bugs in the codebase. The tests should run via a continuous integration pipeline (like GitHub Actions) to ensure every PR is tested before being merged.

Describe alternatives you've considered
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Additional context
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