initiative/specs/002-add-combatant/quickstart.md

Quickstart: Add Combatant

Feature: 002-add-combatant

Prerequisites

pnpm install

Development

pnpm test:watch                   # Watch all tests
pnpm vitest run packages/domain/src/__tests__/add-combatant.test.ts  # Run feature tests
pnpm --filter web dev             # Dev server at localhost:5173

Merge Gate

pnpm check   # Must pass before commit (format + lint + typecheck + test)

Implementation Order

1. Domain event — Add CombatantAdded to events.ts and the DomainEvent union
2. Domain function — Create add-combatant.ts with the pure addCombatant function
3. Domain exports — Update index.ts to re-export new items
4. Domain tests — Create add-combatant.test.ts with all 6 acceptance scenarios + invariant checks
5. Application use case — Create add-combatant-use-case.ts
6. Application exports — Update index.ts to re-export
7. Web hook — Update use-encounter.ts to expose addCombatant callback
8. Web UI — Update App.tsx with name input and add button

Key Files

File	Action	Purpose
packages/domain/src/events.ts	Edit	Add CombatantAdded event type
packages/domain/src/add-combatant.ts	Create	Pure addCombatant function
packages/domain/src/index.ts	Edit	Export new items
packages/domain/src/__tests__/add-combatant.test.ts	Create	Acceptance + invariant tests
packages/application/src/add-combatant-use-case.ts	Create	Use case orchestration
packages/application/src/index.ts	Edit	Export new use case
apps/web/src/hooks/use-encounter.ts	Edit	Add combatant hook callback
apps/web/src/App.tsx	Edit	Name input + add button UI