The book uses two projects:

Contains code for each code listing by name. Each one of them runs as its own, isolated unit test.

npm test src/ch02/2-1.js

Or run all:

npm test src/ch02/2-1.js

Builds pieces of a simple blockchain, transaction management system. You can run each test individually:

npm test test/TransferFunds.spec.js 

Or run all:

npm run test-all