test(follow): unit tests for useFollowList query and cache behaviour

[DSanich]

Summary

Add tests for useFollowList (src/hooks/useFollowList.ts), which loads the current user’s kind 3 contact list from relays with followListCache (localStorage / IndexedDB). followListCache already has dedicated tests — this issue targets the hook’s query function, ordering, empty relay, and newer-vs-cache branches.

Problem

• The hook contains non-trivial branching: no user, zero relay events with optional cache fallback, sort by created_at, isNewerThan vs relay data, extraction of p tags.
• Production logs (debugLog) suggest this path was debugged manually — automated tests prevent regressions when relay behaviour or cache TTL logic changes.

Expected outcome

• renderHook with mocked useNostr, useCurrentUser, and followListCache module:
  • Assert nostr.query filter: kinds: [3], authors: [user.pubkey], limit: 1.
  • When relay returns one kind 3 event: p tags parsed to pubkey list in tag order (or as implemented).
  • When relay returns []: empty array or cached follows when cache exists (match implementation).
  • When relay event is older than cache: cached follows returned (mirror isNewerThan / getCached logic).

What needs to be tested

• Disabled / no user: query returns [] or does not call relay — match enabled semantics in source.
• Success path: sorted events, latest wins.
• IndexedDB effect: optionally assert followListCache.loadFromIndexedDB called when localStorage empty — may require vi.spyOn on followListCache (keep test deterministic).

Mocking strategy

• vi.mock('@/lib/followListCache') with in-memory behaviour or spy real module with controlled return values.
• vi.mock('@nostrify/react') → { nostr: { query: vi.fn().mockResolvedValue([...]) } }.

Acceptance criteria

• src/hooks/useFollowList.test.ts added.
• No real IndexedDB in unit tests unless project already uses idb mocks globally (src/test/setup.ts).
• npm run test + npx tsc --noEmit pass.

Related files

File	Role
src/hooks/useFollowList.ts	Hook under test
src/lib/followListCache.ts + followListCache.test.ts	Existing cache tests

Notes

• useFollowRelationship already has tests — do not conflate; this issue is kind 3 list ingestion only.
• Trim overly verbose debugLog in production later via separate chore if maintainers want — not required to close this issue.

[DSanich]

Created PR for this issue

cc @jalcine @rabble @mbradley @NotThatKindOfDrLiz