New in-theme classes: Buyers computes a shopping-list total, PriceList
stands for the pricing service (random surge, flaky test). One loop, one
lambda-able expression — the third example teaches the move with nothing
else in the way. Pristine repo + reference solution (extract lambda,
slide, extract method with Func<IceCream,int> parameter, pure-lambda
test) + storyboard in the established style. Mirrors the kata's C#
setup (net7.0, MSTest); needs a build check on a machine with the SDK.
Demo on the messier sibling of the exercise method: three unwanted
dependencies in one loop (Scorer incl. static field write, System.out,
clock — clock stripped in 2-min prep). Same six mechanics with SVGs in
the storyboard style, ends green via overload + pure-lambda approval
test. Pointer added to the learning hour's demo section.
Step-by-step refactoring instructions as a single markdown handout with
one diagram per step (legend + steps 0-3, overload inset, pure test,
debrief slides for the dead call and the drift anti-pattern). Derived
from the pattern draft, the learning hour plan, and the rehearsal
findings; slide-ready for later.