Issue 3 from #699 (@alexvaltchev's report): expose a custom-named short
URL per event that bots scrape for OG previews and browsers redirect to
the underlying gallery. WhatsApp / iMessage / Facebook cache the OG
metadata by the URL they crawl, so the SHORT URL becomes the cache key
— admins can rotate or split-test underlying gallery URLs without
re-pushing a fresh link to clients.
Additive feature; no existing route, table, or column is modified.
## Backend
- `gallery_short_urls` table (migration 150): id, short_slug UNIQUE,
event_id FK CASCADE, target_path TEXT, created_by/at, hit_count,
last_hit_at, deleted_at/by. hasTable-guarded so the migration is
idempotent on re-run.
- `src/services/galleryShortUrlService.js` — validator + CRUD +
resolver. Slug rules: `/^[a-z0-9](?:[a-z0-9-]{0,62}[a-z0-9])?$/`,
reserved blocklist (admin, api, auth, gallery, og, s, login, ...).
target_path snapshots at create-time from the event + global
short-URL toggle, so a later flip of the toggle does NOT silently
change where existing short URLs resolve.
- `src/routes/adminShortUrls.js` — `GET/POST
/api/admin/events/:eventId/short-urls`, `DELETE
/api/admin/short-urls/:id`. Structured errors: 400 INVALID_SLUG,
409 SLUG_TAKEN (with `suggested`), 404 EVENT_NOT_FOUND. Gated by
events.view / events.edit + requireEventOwnership.
- `server.js` /s/:shortSlug public route. Bot UA → server-render the
same OG metadata the existing /og/gallery/<slug> handler produces,
then override og:url to point at /s/<shortSlug> itself (cache-key
invariant — social platforms key by the URL they scrape).
Browser UA → 302 to target_path. Soft-deleted slug → 410 Gone
(intentional-delete signal, distinct from 404 unknown slug).
Hit accounting is fire-and-forget.
## Frontend
- `services/shortUrls.service.ts` — list/create/remove.
- `components/admin/ShortUrlsCard.tsx` — per-event card on the
EventDetailsPage. Form for custom or auto-generated slug, list with
copy-to-clipboard + soft-delete. SLUG_TAKEN error surfaces the
service's `suggested` slug with a "use suggested" button.
- i18n: events.shortUrls.* added to EN + DE.
## Tests
78 new tests, all passing:
- `__tests__/utils/galleryShortUrlValidation.test.js` (48) — pure-
function tests for validateSlug: accepts/rejects, reserved-slug
blocklist, path-traversal + URL-injection vectors.
- `__tests__/integration/galleryShortUrls.test.js` (19) — service
layer against a real SQLite DB. Covers custom + auto-generated
slugs, collision + SLUG_TAKEN + suggested, target_path
snapshotting (backward-compat invariant), soft-delete + slug
rotation, hit counting.
- `__tests__/integration/galleryShortUrlRoute.test.js` (11) —
HTTP-level: 302 redirect for browser UA, 200 + OG HTML for bot UA,
og:url canonical points at /s/<slug>, 410 for soft-deleted +
orphaned events, 404 unknown + malformed.
Regression sweep: 47 existing migration-chain integration tests still
pass; migration 150 is additive only.
## Backward compatibility
- Existing `/gallery/<slug>`, `/gallery/<32-hex-share-token>`,
`/gallery/<slug>/show/<token>`, `/og/gallery/<slug>`,
`/og/gallery/<slug>/cover` routes are untouched.
- The `/s/` namespace is new; no existing route lives there.
- Migration 150 only ADDs the new table — no ALTERs on existing
schema, no destructive changes.
- target_path is snapshotted at create-time so flipping the global
"Use short gallery URLs" setting after a short URL exists does NOT
change where that short URL resolves.
Paul Nothaft