25 TDD tasks across five phases: foundation, pure domain core, IndexedDB
persistence, JSON/ODS export, UI, and shipping (PWA + Docker + CI).
Self-review caught five defects, fixed inline:
- distributeByWeight divided by zero on all-zero weights, which a
zero-total purchase reaches and which would take the whole fold down
- summaryView's fold binding needed an explicit type or CI typecheck fails
- a duplicated module import in registerSw.ts
- a shell render test that would break once its routes read the store,
since happy-dom has no IndexedDB
- an unreadable assertion in the ODS numeric-cell test
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Design for a personal budgeting PWA replacing a spreadsheet workflow.
Key decisions captured:
- Static SPA, no backend in the data path, so it deploys to both GitHub
Pages and a self-hosted Docker image from one build artifact
- Bun toolchain (bun init --react=shadcn); no Vite, no Electron
- Pure derivation core over an IndexedDB fact store; envelope rollover
makes caching worthless, so every figure is folded from raw facts
- One Purchase entity covers simple, split, and financed purchases, which
is what lets splits and finance plans compose without special-casing
- Money is a float, with mandatory rounding at boundaries and last-part-
by-subtraction so distributed parts sum exactly to the whole
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
