weirsoe-party-protocol/docs/ISSUE-277-SHARED-I18N-PARITY-ARTIFACT.md

ISSUE-277 Artifact — shared i18n registry parity report (Django ↔ Angular MVP)

Issue: #277 ([READY][#175][P3] Shared i18n registry artifact: backend/frontend keyspace parity report)

Artifact metadata

• artifact_id: issue-277-shared-i18n-parity-report
• artifact_version: 1.0
• catalog_source: shared/i18n/lobby.json
• generator: scripts/report_i18n_parity.py

Naming/version rules (email-manager-inspired strategy)

• Single canonical artifact per issue: issue-bundne rapporter navngives docs/ISSUE-<nr>-<slug>-ARTIFACT.md.
• Stable artifact identity: artifact_id ændres ikke ved tekstlige opdateringer i samme rapporttype; det er den faste reference i review/ops.
• Explicit artifact versioning: artifact_version bumpes, når rapportlogik eller scope ændres, så drift/review kan se forskel på format- vs. dataændringer.
• Shared namespace first: keys refereres med fulde navnerum (frontend.ui.*, frontend.errors.*, backend.error_codes.*, backend.errors.*) i stedet for lokale aliases i artefakter.
• Source-of-truth before consumers: rapporten afledes fra shared/i18n/lobby.json; Django/Angular beskrives som consumers af samme registry og ikke som parallelle kontrakter.

MVP-critical parity summary

• Frontend UI gameplay keys checked: 16 → OK
• Frontend error keys checked: 7 → OK
• Backend gameplay/error codes checked: 9 → OK
• Distinct frontend error keys reached from backend MVP flow: 6 (join_failed, nickname_invalid, nickname_taken, session_code_required, session_not_found, start_round_failed)

Status: Shared locale matrix is aligned (en, da) and backend→frontend error handling is contract-complete for MVP-critical flow.

Django ↔ Angular parity matrix (MVP-critical error contract)

Backend code (backend.error_codes.*)	Django message key (backend.errors.*)	Angular key (frontend.errors.*)	Locales en/da	Parity note
session_code_required	session_code_required	session_code_required	OK	1:1
nickname_invalid	nickname_invalid	nickname_invalid	OK	1:1
session_not_found	session_not_found	session_not_found	OK	1:1
session_not_joinable	session_not_joinable	join_failed	OK	mapped alias
nickname_taken	nickname_taken	nickname_taken	OK	1:1
category_slug_required	category_slug_required	start_round_failed	OK	many:1 collapse
category_not_found	category_not_found	start_round_failed	OK	many:1 collapse
round_start_invalid_phase	round_start_invalid_phase	start_round_failed	OK	many:1 collapse
round_already_configured	round_already_configured	start_round_failed	OK	many:1 collapse

Scope notes

• Django consumes backend codes/messages directly from shared/i18n/lobby.json via lobby/i18n.py.
• Angular consumes the same registry via frontend/shared/i18n/lobby-loader.ts and runtime helpers in frontend/angular/src/app/lobby-i18n.ts.
• Parity in MVP is therefore strongest on the shared error contract and locale matrix; gameplay UI labels are frontend-owned but still live in the same registry.

Verified MVP gameplay UI keyspace present in the shared registry

• frontend.ui.host.title
• frontend.ui.player.title
• frontend.ui.common.session_code
• frontend.ui.player.nickname
• frontend.ui.player.join
• frontend.ui.host.start_round
• frontend.ui.host.show_question
• frontend.ui.player.lie_label
• frontend.ui.player.submit_lie
• frontend.ui.player.submit_guess
• frontend.ui.host.mix_answers
• frontend.ui.host.calculate_scores
• frontend.ui.host.load_scoreboard
• frontend.ui.host.final_leaderboard
• frontend.ui.player.final_leaderboard
• frontend.ui.common.points_short

Concrete deviations / follow-up items

1. Error granularity collapse remains intentional: backend codes category_slug_required, category_not_found, round_start_invalid_phase, round_already_configured all map to frontend.errors.start_round_failed. Follow-up only if product wants case-specific Angular copy instead of one shared host failure message.
2. Frontend-only fallback copy is not mirrored in Django: frontend.errors.unknown and frontend.errors.session_fetch_failed are Angular-side resilience keys, not backend contract keys. Follow-up if API responses should expose stable backend equivalents for these states.
3. Gameplay UI labels are registry-shared but not backend-rendered: frontend.ui.host.*, frontend.ui.player.*, and frontend.ui.common.* are available in the shared artifact, but Django currently consumes only the backend error slice. Follow-up only if server-rendered views must guarantee the same UI label surface as Angular.

Re-run

python3 scripts/check_i18n_drift.py
python3 scripts/report_i18n_parity.py