📘 Issue Description Priority: CRITICAL
Current: Backend booking tests only cover basic GETs. Critical payment + booking + smart contract flow is not covered end-to-end. We must validate business rules, security checks, and failure recovery for a financial flow (USDC on Stellar + escrow) with realistic scenarios.
Goal: Comprehensive integration tests for booking creation, payment confirmation (Trustless Work), and smart contract interactions, including error paths, race conditions, and authorization.
🔍 Steps Extend apps/backend/tests/integration/ with a booking flow suite (new file: booking-flow.int.test.ts). Add fixtures for users/properties/dates under apps/backend/tests/fixtures/. Add blockchain/payment mocks under apps/backend/tests/mocks/ (Trustless Work API + Soroban interactions). Cover scenarios: Property availability validation POST /bookings (pending) Payment confirmation (Trustless Work) → PUT /bookings/:id/confirm Status transitions: pending → confirmed → completed → cancelled Race conditions: concurrent bookings on same dates Validation: amount matching between backend and on-chain intent Security: unauthorized access, invalid tokens, replay/challenge expiry Failure modes: network timeouts, Trustless errors, contract failures (use mocks) Ensure idempotency of payment confirmation; protect against replay. Document how to run integration tests locally and in CI. ✅ Acceptance Criteria
High coverage (≥90% critical paths) of booking endpoints, including error branches
Race condition tests that prevent double-booking
Amount validation between backend and on-chain intent
Security checks: authZ/authN, replay/nonce/expiry enforced
Robust mocks for blockchain/payment with deterministic outcomes
Test suite completes under ~90s in CI with parallelization
README/docs for setup, running, and conventions 🌎 References Current tests: apps/backend/tests/integration/booking.test.ts Booking service: apps/backend/src/services/booking.service.ts Smart contracts: apps/stellar-contracts/contracts/booking/ Trustless Work: apps/backend/src/blockchain/trustlessWork.ts 📜 Additional Notes Start with mocks (contract tests) before wiring real network calls. Consider chaos tests (timeouts/retries) and rate limiting tests for payment endpoints. Related PRs Test scaffolding (Playwright + integration test skeleton): PR test-scaffolding