bookie-tddlisted

# bookie-tdd — TDD Template for Bookie Tasks Use when adding or changing bookie validation rules, ledger write contracts, or bookie subagent logic. Applies to any task touching `src/ledger/bookie-validator.ts`, `src/ledger/kinds.ts`, `src/ledger/merge-guard.ts`, or any other pure-validator module in `src/ledger/`. ## Guiding principle **Pure functions, no DB.** Bookie validators are total functions over inputs. They take typed arguments and return typed errors or void. They never touch `~/vault/ledger.db`. This makes them trivially testable: one `describe`/`test` block, one `expect()` per assertion, no setup/teardown. When the logic is pure, TDD is cheap. Write the failing test first. ## Red-green-refactor loop for bookie tasks ### Phase 1 — Red: write the failing acceptance test The test encodes a **behavior** (not an implementation). It lives in `src/ledger/<module>.test.ts` alongside the module under test. For a new validator: ```typescript import { test, expect } from "bun:test"; import { validateBookieWrite, type BookieWriteInput } from "./bookie-validator"; // ── new behavior ──────────────────────────────────────────────────────────── test("validateBookieWrite: rejects kind='sprint' without source_module", () => { const errs = validateBookieWrite( { kind: "sprint", class: "ops", urgency: "nominal", class_rationale: "test" }, new Set(["arc-chat"]), ); expect(errs.some((e) => e.field === "source_module")).toBe(true); }); ``` For a new enum value: