pedwfrontend/memory-bank/techContext.md

Tech Context — PEDW FrontEnd

Languages and framework

• JavaScript-first codebase (TypeScript tooling present).
• Next.js ^14.2.28 with Pages Router.
• React ^18.2.0.

Core libraries in active use

• Auth: next-auth + Prisma adapters.
• Data/state: redux, react-redux, next-redux-wrapper, redux-persist, redux-thunk, redux-form.
• Data access/integration: axios, crypto-js, jsonpath-plus.
• i18n: next-translate, locale config in i18n.js.
• Storage/infrastructure integrations: @azure/storage-blob, @azure/storage-queue, @azure/identity.
• Notifications/telemetry: notifications-node-client (GOV.UK Notify), applicationinsights.
• PDF/maps: @react-pdf/renderer, react-pdf, leaflet, react-leaflet, google-map-react.

Runtime and configuration

• Standard app start script uses Next runtime (npm start).
• Additional custom server entries exist (server.js, server/server.js) but are currently treated as non-active for the refactor baseline unless deployment evidence indicates otherwise.
• Environment-driven config for auth, relay/API roots, hash key, notify key, and database URL.

Relay forwarding hardening policy knobs (P2-S3)

• Shared relay middleware now enforces centralized timeout/retry behavior for relay-backed GET flows.
• Supported env knobs:
  • RELAY_TIMEOUT_MS (default 8000, clamped 100..30000)
  • RELAY_RETRY_MAX (default 2, clamped 0..4)
  • RELAY_RETRY_BASE_DELAY_MS (default 200, clamped 0..5000)
  • RELAY_RETRY_MAX_DELAY_MS (default 1200, clamped 0..5000)
• Retry classification:
  • retryable: 408, 429, 5xx, selected transient transport errors
  • non-retryable: deterministic client/auth statuses (400, 401, 403, 404, 422) and other explicit non-retryable HTTP statuses
• Logging behavior:
  • structured redacted relay events emitted for retry/failure
  • duplicate endpoint-layer error logging suppressed when relay layer already emitted terminal failure log

Tooling and quality gates

• Linting: npm run lint (next lint).
• Formatting conventions from .prettierrc: 4 spaces, no trailing commas.
• Prisma client generation script available: npm run prisma:generate.

CI/CD and deployment artifacts

• azure-pipelines.yml exists (legacy-looking Node 10 build pipeline).
• Jenkinsfile exists (Node 20 + Docker build/push/deploy flow).
• Dockerfile exists (Node 20 Alpine runtime).
• Repository contains mixed deployment artifacts; active production path should be treated as environment-dependent unless confirmed.

Local development workflow

• npm install
• npm run dev
• npm run lint
• npm run build && npm start for production-like verification