How to actually write unit tests

JavaScript testing involves using assertions to verify expected outcomes of functions. Chai, an assertion library, is often paired with Mocha, a testing framework, to run tests. Tests are structured using Mocha's it() method, which describes the test and contains assertion functions. An example of testing an add() function is provided, demonstrating how to write unit tests for different scenarios. The process involves defining expectations, writing assertions, and running tests to identify any errors in the code.