The code provided seems to be a test suite for an API workflow. It uses the Node.js assert module to make assertions about the expected behavior of different API endpoints.
In particular, the describe function is used to group related tests together under a common description, while the it function defines individual tests with a specific behavior to test. The before and after functions are used to set up and tear down any necessary resources, respectively.
Based on the code, it appears that this test suite is intended to test an API that requires authentication using a token. The first test checks that a 401 Unauthorized response is returned if invalid credentials are provided. The second test checks that a token is returned when valid credentials are provided. The third test checks that a 400 Bad Request response is returned if no token is provided. Finally, the fourth test checks that a 200 OK response is returned if a valid token is provided.
As for the reference to Erick Wendel's course.