Blackjack Ensemble — Learn the Repo, Practise TDD

Short, hands-on lessons that take you from “I just cloned it” to confidently pairing on Ted Young's blackjack-ensemble-blue. Do one lesson, complete its task, say “done”, and I'll test you before we move on.

The mission When it's your turn at the keyboard in the mob, you know where code lives, why the tests are shaped the way they are, and how to drive a change red→green→refactor without slowing the team down. See MISSION.md.

How this works

Each lesson is one HTML page: a little knowledge, quick recall quizzes, then a hands-on task in the real repo.
You do the task in IntelliJ, then tell me “done”. I read your code, run your tests, and quiz you. We only advance when it's solid.
Keep the two reference cards open while you work.

▸ IntelliJ macOS Shortcuts · ▸ Repo Map (architecture + glossary) · ▸ find() & event replay · ▸ Learning Records (dated session log)

Lessons — do them in order

0001 · The Lay of the Land ready
Open the project with JDK 25, run the suite, meet the hexagonal architecture and the one deliberate red test.
0002 · The Domain Core ready
Card, Rank, and the soft-ace logic of Hand.value(). Write your first domain tests.
0003 · Testability Patterns ready
StubDeck, StubDeckBuilder, GameBuilder, custom AssertJ, readable names — why this code is easy to test.
0004 · Paying the Winners ready
A genuine RED-first cycle: wire the game-over payout into PlayerAccount in GameService.execute() — the exact seam tonight's ensemble picks up.
0005 · Settling the Losers ready
Why the balance is already right for losers and pushes — so you must test the event. Drive the win/lose branch red-first, then learn when to refactor it into a polymorphic settle().

0006 · Event Sourcing: PlayerAccount planned
EventSourcedAggregate, the sealed PlayerAccountEvent hierarchy, apply() with record patterns, and reconstitute().
0007 · The Application Layer & Ports planned
GameService as a use-case orchestrator; ports, spies, and the createForTest seams.
0008 · The Web Adapter planned
Spring MVC controllers, Thymeleaf views, and MockMvc tests — the outer skin.
0009 · Capstone — Implement “insufficient balance throws” capstone
Turn the ensemble's real red test green, test-first. We'll untangle the PlayerId / exception-type puzzle together — the exact work you'll pair on.

Start here

Open Lesson 0001, do section 6's task, and say “done”. I'll generate 0004 once 0001–0003 are under your belt — lessons are written to your pace, one step ahead of where you are.

This course adapts. If a lesson is too easy or too hard, tell me and I'll adjust the next one. Want a lesson on something specific (Spring DI, the CSV repository, ArchUnit)? Just ask.