test(comments): unit tests for NIP-22 comment tags and usePostComment

[DSanich]

Summary

Add pure unit tests for NIP-22 (kind 1111) tag construction and hook tests for usePostComment, including onMutate / onSettled cache behaviour for ['nostr', 'comments', …] queries. Comments power threading and Funnelcake indexing — tag mistakes cause missing threads, not loud UI errors.

Problem

• src/hooks/usePostComment.ts builds a large conditional matrix: URL vs event roots, addressable vs replaceable kinds, reply vs top-level branch, NKinds from @nostrify/nostrify.
• Logic is inline in mutationFn — hard to review and not covered by CommentForm.test.tsx (that file mocks the hook entirely).
• Wrong E/A/a/e/P/p/K/k combinations are exactly the bugs this suite should prevent.

Expected outcome

1. Preferred: Extract buildNip22CommentTags(root, reply, content) (or similarly named) into src/lib/ returning string[][], with table-driven tests for representative cases:
   • Addressable 34236 video root with d tag → expect A, E, K, P as in current code.
   • Top-level vs reply: duplicate a/e branch when reply is absent (mirror implementation).
   • URL roots: I/i tags and hostname-based K/k.
2. usePostComment.test.ts: mock useNostrPublish, assert publishEvent receives built tags; verify onMutate cancels/updates queries as implemented.

What needs to be tested

Pure tag builder (if extracted)

• At minimum three fixtures: video addressable event, generic event root, URL root; plus one reply-to-comment case if supported by types.
• Snapshot or deep-equal tags array order — order may matter to some indexers.

Hook

• publishEvent invoked with kind: 1111 and expected tags for each fixture.
• Cache: cancelQueries / invalidateQueries keys align with rootId derivation (root.id vs URL string).

Mocking strategy

• Construct minimal NostrEvent objects (id, pubkey, kind, tags, content, created_at, sig) — no relay I/O.
• vi.mock('@/hooks/useNostrPublish').

Acceptance criteria

• Tests live next to code or under src/lib/ for extracted builder + src/hooks/usePostComment.test.ts.
• No network.
• npm run test + npx tsc --noEmit pass.

Related files

File	Role
src/hooks/usePostComment.ts	Mutation + tag logic
src/components/comments/CommentForm.test.tsx	Mocks hook — not coverage

Notes

• Out of scope: full useComments infinite query tests unless time permits — file a follow-up issue if parsing/query filters need coverage too.
• If extraction is rejected by reviewers, document mutation-only tests with duplicated expectations — still better than zero coverage.

[DSanich]

@jalcine @rabble @NotThatKindOfDrLiz Created PR for this issue. Could you review it, please.

[jalcine]

Not against it but this issue's body seems like it was generated by AI. What was the goal of this issue? How did you come up with the problem and expected outcome and what do they reference? This makes it hard to ascertain the intent of this issue (and it helps if discussion happens before a PR is opened).

[DSanich]

@jalcine You're right—the problem looks like a checklist, not what I imagined 😅

My goal was to test NIP-22 comment tags in usePostComment. Incorrect E/A/a, etc. often look fine in the UI, but the discussion threads don't display—CommentForm.test.tsx simulates a hook, so it doesn't check anything about what we post.

I was working with a comment stream, read usePostComment.ts (a large matrix of inline tags + caching by ['nostr', 'comments', rootId]), and wanted to block it before refactoring. Extracting it into a task was just one option; hook-only tests would also work, if that's more convenient for you.

I'd be happy to discuss it.