Read it. Try it.
TestBucks.
The book’s companion materials
TestBucks is the fictional coffee-shop website used throughout the book. Explore its menu, customize a drink, inspect the cart, and try a simulated checkout. Everything here uses synthetic data. No real payment or order is sent.
See the TestBucks flows
Explore seventeen screenshot examples and six isolated, runnable teaching variants.
Explore screenshot flows →Every code example. Ready to copy.
Browse the book’s code snippets, JSON records, prompts, sample responses, and Carbon examples by chapter. Copy individual examples or download the complete collection.
Practice the concepts
Explore 16 course exercises matched to the book chapters, with copyable prompts and sample artifacts.
Browse all exercises →Your first check
Open the deliberately faulty menu and search for vanilla. Capture a screenshot and ask your AI coding agent to find the issue. Then compare it with the normal menu using the same search.
This is an intentional learning fixture—not a finding against a real coffee company.
Artifacts used in the book
Download these screenshots to inspect with your AI coding agent. These are captured app states; the book’s illustrative AI responses are not live audit results.
Run it locally. Make it your own.
- Source ZIP — app, cup image, setup instructions, and all three screenshots.
- Download the HTML source — for code review and testability exercises. Download the cup image and bug logo alongside it.
- Read the setup and exercise notes.
The starter supports menu search, drink options, cart changes, discounts, simulated payment outcomes, order history, and reset. Accounts, real payment services, distributed systems, and native clients in later chapters are illustrative extensions, not features of this starter.
Use only fictional information. TestBucks is not affiliated with Starbucks. Browser state is saved locally on your device.