TASK22168 endpoint account contract consistency slice

memory-bank/progress.md

@@ -753,6 +753,55 @@
 - `node tests/phase16/service-behaviour.test.cjs` -> **pass** (4/4)
 - `npm run lint` -> **warnings only** (pre-existing `react-hooks/exhaustive-deps` warnings)
 
+## Latest update (2026-03-19 — TASK22168 endpoint account contract consistency slice)
+
+- New branch created from `origin/SIPS-Development` with required work item prefix:
+    - `TASK22168-endpoint-account-contract-consistency`
+- Delivered next coherent low-risk `pages/api/endpoint/**` slice after TASK22109 across:
+    - `pages/api/endpoint/getaccounts_api.js`
+    - `pages/api/endpoint/getemailaccountcheck_api.js`
+    - `pages/api/endpoint/getpreferredlanguage_api.js`
+- Scope delivered:
+    - removed dead/noisy code in touched handlers (unused imports and commented debug remnants)
+    - standardized structured negative-path handling for:
+        - missing required `emailAddress`
+        - catch/failure paths
+    - preserved success response contracts by returning unchanged upstream `data`
+- Added focused phase21 endpoint contract coverage:
+    - `tests/phase21/endpoint-handler-contract.test.cjs`
+    - extended `tests/phase21/api-contract-slice1.test.cjs` runner
+
+### Validation snapshot (TASK22168)
+
+- `node tests/phase21/api-contract-slice1.test.cjs` -> **pass**
+    - helper: 4/4
+    - file-handler: 11/11
+    - email-handler: 12/12
+    - endpoint-handler: 7/7
+- `npm run lint` -> **warnings only** (pre-existing `react-hooks/exhaustive-deps` warnings)
+
+### Risks + mitigations (TASK22168)
+
+- Risk: endpoint contract drift in success payloads.
+    - Mitigation: success responses kept as upstream `data` payload via `respondSuccess`.
+- Risk: over-broad behavior change in account/login adjacent APIs.
+    - Mitigation: scoped to 3 low-risk handlers only; no auth/session/security flow changes.
+- Risk: regression in negative-path status/shape expectations.
+    - Mitigation: added explicit phase21 missing-input and catch-path assertions for each touched endpoint.
+
+### Rollback plan (TASK22168)
+
+1. Revert endpoint files:
+    - `pages/api/endpoint/getaccounts_api.js`
+    - `pages/api/endpoint/getemailaccountcheck_api.js`
+    - `pages/api/endpoint/getpreferredlanguage_api.js`
+2. Revert phase21 test updates:
+    - `tests/phase21/endpoint-handler-contract.test.cjs`
+    - `tests/phase21/api-contract-slice1.test.cjs`
+3. Re-run:
+    - `node tests/phase21/api-contract-slice1.test.cjs`
+    - `npm run lint`
+
 ### Manual HTTP checks (Phase 16)
 
 - Dev server on `http://localhost:3002`.