Here's the basic workflow:

[~]                  $ git clone /~https://github.com/comehome-lab/backend-challenge
[~]                  $ cd backend-challenge
[backend-challenge]  $ npm install
[backend-challenge]  $ cd min
[min]                $ vi index.js
[min]                $ npm test

This uses a basic TDD approach so take a look at the test.js file in each directory to see what needs to be implemented, write an index.js as the solution file