The compiled version of the app can be seen in the dist directory. It has an index.html file, which contains the app
To make changes to the app, you must install dependencies by running yarn.
After that npm start will run the watchers, and run the app with Hot Module Replacement enabled. Thus it is possible to modify the logic of the app - without even losing the state.
While in development mode, it is also possible to do time travel, and explore the previous states, by using the panel on the bottom right corner.
I was hoping to write some randomly generated Fuzz tests for the application, however I didn't have enough spare time for that.
To prove that the app works - there is at least 1 unit test that proves adding items to the cart is possible.
To run tests, use npm t.