Records the lasting decision behind the #730 fix: exact-case-first
resolution, deterministic lowest-id case-insensitive fallback, and the
explicit refusal of a unique(lower(name)) constraint (collisions are
valid canonical nodes). Previously the rationale lived only in code
comments and the issue body. Raised as a blocker in the PR #733 review.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Two adversarial gaps from PR #733 review:
- Unit: exact-case must win even when its id is NOT the lowest, proving
exact-case short-circuits before the lowest-id tie-break (a naive
"lowest id across all CI matches" would pick the wrong row).
- Integration: assert findAllByNameIgnoreCase folds the UPPERCASE
"GLÜCKWÜNSCHE" — the exact string findOrCreate passes — so the umlaut
proof matches the resolution path under test, not a lowercase probe.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The lowest-id tie-break stream is guarded non-empty, so .get() never
throws — but the project bans Optional.get(). Switch to .orElseThrow()
for the project idiom. No behaviour change.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Mocked TagServiceTest can't prove the two things that actually broke:
that findAllByNameIgnoreCase folds umlauts the way Postgres LOWER() does,
and that saving a document tagged with a case-colliding tag no longer
throws NonUniqueResultException. Testcontainers postgres:16-alpine:
- updateDocument on a doc tagged with the child "weihnachten" succeeds
and keeps exactly the child tag (not the parent).
- findOrCreate("GLÜCKWÜNSCHE") resolves the Glückwünsche/glückwünsche
umlaut pair deterministically (lowest id) without throwing — the
regression catcher a plain-ASCII pair would miss.
- bulk-edit funnels through resolveTags → findOrCreate, guarding a
future refactor that bypasses it.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
findOrCreate used tagRepository.findByNameIgnoreCase, which returns
Optional<Tag> and threw NonUniqueResultException whenever two tags
collided case-insensitively (a canonical parent and its same-named
lowercase child). Every document carrying such a tag became un-editable:
any save re-resolves the whole tag set by name and blew up with a 500.
Replace the throwing lookup with exact-case-first resolution: findByName
(exact) → findAllByNameIgnoreCase (lowest-id, deterministic, never
throws) → create. Delete findByNameIgnoreCase so the throwing call can't
be reintroduced. Case collisions are valid tree nodes — no migration, no
unique(lower(name)) constraint.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
