test(registry): pin useRegistryUpdateMutation coverage to fix Coveralls flake

[samuv]

The coverage/coveralls check has been flapping between "no change" and "Coverage decreased (-0.02%) to 63.188%" on PRs that touch only docs/CI (e.g. #2032). Coveralls pinpoints the regression to exactly one line: renderer/src/common/components/settings/registry/use-registry-update-mutation.ts:59 — the generic throw e rethrow inside putRegistry's .catch. That line has no dedicated test; its coverage is entirely ambient from renderer/src/common/components/settings/tabs/__tests__/registry-tab.test.tsx, which never forces a non-matching PUT error. Depending on MSW teardown and test scheduling it sometimes flipped to uncovered, producing the -2.25% on this file (-0.02% total) that Coveralls was reporting.

• Add renderer/src/common/components/settings/registry/__tests__/use-registry-update-mutation.test.ts — 12 direrenderHooktests that pin every branch ofuseRegistryUpdateMutation`
• Happy paths: type = default (empty PUT body), type = url ({ url } + cache updated), type = local_path ({ local_path }), type = api_url with both auth fields (PUT + postApiV1BetaRegistryAuthLogin + invalidateQueries), type = api_url with only client_id (partial auth), type = api_url with neither field (no auth, login skipped), and the post-success removeQueries for registry-name-servers
• putRegistry error branches: api_url + OIDC pattern → REGISTRY_WRONG_ISSUER_TOAST, api_url + auth-required pattern → REGISTRY_AUTH_FIELDS_REQUIRED_TOAST, api_url + non-matching string → throw e (line 59 via path A), url + JSON error → throw e (line 59 via path B)
• authenticateWithRegistry error branch: PUT succeeds, login fails → mutateAsync rejects with REGISTRY_WRONG_AUTH_TOAST, invalidateQueries for the registry key was called, fire-and-forget logout POST was made
• Uses the existing es (mockedPutApiV1BetaRegistryByName, mockedPostApiV1BetaRegistryAuthLogin, mockedPostApiV1BetaRegistryAuthLogout) — no new infrastructure

Why this removes the jitter

v8 records per-line hit counts. Once line 59 is hit deterministically by an explicit assertion, it stays at covered on every run, so base and head SHAs report identical coverage for this file. Verified locally across three back-to-back pnpm run test:coverage runs on the relevant files — the lcov block for use-registry-update-mutation.ts is byte-identical, and DA:59 is pinned at hit-count 3.

Not changed in this PR (deliberate, follow-up)

• No change to .github/workflows/_unit-tests.yml, .github/workflows/on-pr.yml, or vitest.config.ts — the workflow still runs on every PR and uploads to Coveralls, it just stops producing a non-deterministic delta
• The duplicate coverage/coveralls status post (two identical entries on the same (sha, context) pair, ~2.5 minutes apart) is orthogonal to the flake and left low-up: one-line github-token: '' on coverallsapp/github-action in _unit-tests.yml, or disabling the Coveralls GitHub App's PR-status integration in repo settings. After this PR the single remaining status would already be green.

[Copilot]

Pull request overview

Adds deterministic unit tests for useRegistryUpdateMutation to stabilize Coveralls line coverage and prevent flapping caused by previously-ambient execution of the throw e rethrow branch in putRegistry.

Changes:

• Add a new hook-focused test suite that exercises all useRegistryUpdateMutation branches (success + error paths).
• Explicitly covers putRegistry error classification (OIDC discovery/auth-required) and the generic rethrow behavior.
• Covers authenticateWithRegistry failure behavior (rejects with known toast + invalidation + logout call).