# Implement TDD practices in PalaceApp

**Linear:** MAN-68 — https://linear.app/manglasabang/issue/MAN-68/implement-tdd-practices-in-palaceapp
**Status:** Next Up
**Project:** palacering

## Description
Adopt test-driven development across PalaceApp. Best practices to follow:

1. **Red-Green-Refactor per feature** — Write a failing test first, write minimum code to pass, then clean up.
2. **Test at the right layer** — Unit tests (Jest/pytest) for business logic, integration tests for API contracts, E2E (Playwright/Detox) sparingly for critical flows.
3. **Colocate tests with source** — `foo.ts` → `foo.test.ts` next to it. `foo.py` → `test_foo.py`.
4. **Test behavior, not implementation** — Tests describe *what* code does, not *how*.
5. **Enforce in CI** — Run `turbo test` on every PR, add coverage thresholds (start at 60%), tighten pre-commit hook.
6. **Backfill strategically** — Add tests whenever touching existing files.
7. **Keep tests fast** — Mock external deps, keep `turbo test` under 30s.