feat(unti-test): introduce

[AugustinMauroy]

Context

We have to test our app, it's very important to provide the best user experience, and avoid bugs. But in the javascript ecosystem, there are plenty of ways to test your project, so you need to choose the right one.

here's a list of tools:

• jest
• Playwright
• cypress
• node.js internal test-runner

If you have any other tools you like tell it

There are still things to be decided. What tools to use, what to test?

Todo

• [ ] reached a consensus on how and what to test.
• [ ] added test.
• [ ] document how to test different parts of the code.