Author of the book here. Thanks for the shout out! I'm happy to hear that you appreciate the book exactly in the way it was intended to - little magic, lots of code and unit tests.

I'm also super curious about your "not in an idiomatic way" comment. If you have a minute, feel free to send me a longer version - me at thorstenball.com. I'd really love to hear what you'd do differently and what could be more idiomatic.