feat(enrichment): empty-catch / error-swallow analyzer

[bohdansolovie]

Summary

Fixes #2014

• Add ErrorSwallowFinding and a local errorSwallow analyzer that flags newly-added catch/except blocks that swallow errors: empty body, unused binding, or bare return null
• Brace-balanced catch-body extraction for single-line and multi-line added hunks; JS/TS optional-binding catch {} and Python except: pass supported
• Binding references use identifier-boundary lookarounds (including $ in valid JS identifiers), not \b word boundaries
• Register the analyzer in the REES registry with render/docs/metadata; sync src/review/enrichment-analyzer-names.ts and generated .env.example / UI metadata
• Add review-enrichment/test/error-swallow.test.ts covering empty/return-null/unused-binding cases, log/rethrow/$-binding/nested-brace non-flags, multiline catches, cap, and public-safe brief rendering

Test plan

• cd review-enrichment && npm run build && npm run metadata && node --test test/error-swallow.test.ts test/analyzer-registry.test.ts
• CI validate-code

Made with Cursor

[superagent-security]

Superagent didn't find any vulnerabilities or security issues in this PR.

[loopover-orb]

Warning

🟨🟨🟨🟨🟨🟨🟨🟨🟨🟨🟨🟨

⏸️ Gittensory review result - manual review recommended

_{Review updated: 2026-07-05 16:34:03 UTC}

10 files · 1 AI reviewer · no blockers · readiness 80/100 · CI green · clean

⏸️ Suggested Action - Manual Review

Review summary
Adds the `errorSwallow` enrichment analyzer end-to-end: a new `error-swallow.ts` pure-compute module, `ErrorSwallowFinding` type, registry/render/metadata/UI/names/env-example wiring, and a solid test file. The core logic is correct: `parseCompleteCatchLine` brace-balances single-line catches, `scanPatchForErrorSwallow` accumulates multi-line pending blocks with the same balance approach, `referencesBinding` uses identifier-boundary lookarounds (`[A-Za-z0-9_$]`) instead of `\b` so `$`-prefixed bindings work, and the known limitation (string-literal braces are not stripped) is explicitly documented. All registration touchpoints are synchronized. No correctness or data-integrity defects are visible.

Nits — 5 non-blocking

• registry.ts:1117 and apps/gittensory-ui/src/lib/rees-analyzers.ts:1039-1040 hardcode `25` and `2000` as inline literals; `error-swallow.ts` keeps them as unexported module constants (`MAX_FINDINGS`, `MAX_LINE_CHARS`), so the registration sites can't import them — either export the constants or at minimum add a comment tying the values back to the source file so they don't drift.
• referencesBinding (error-swallow.ts) calls `new RegExp(...)` on every invocation; since this runs inside a per-line loop over patch content, compile the regex once per unique binding name rather than re-creating it each call.
• The innermost pending-tracking branch of `scanPatchForErrorSwallow` reaches depth 5 (flagged by the analyzer's own deep-nesting rule at error-swallow.ts:84) — extracting the `maybeStartPending` logic into a small helper would both flatten this and make the function easier to follow.
• test/error-swallow.test.ts has no test for a catch that uses a `$`-prefixed binding (e.g., `catch ($err) { handle($err); }`) to confirm the custom lookaround fires correctly; a single assert in the existing 'does not flag' test would close the gap.
• Python `except ValueError: pass` (no `as` binding) is classified as `empty-catch` rather than something like `pass-body`; this is defensible but slightly misleading since the body isn't empty — add a brief comment to `bodySwallowsError` explaining the intentional classification.

Signal	Result	Evidence
Code review	✅ No blockers	1 reviewer
Linked issue	✅ Linked	#2014
Related work	✅ No active overlap found	No same-issue or scoped active PR overlap found.
Change scope	✅ 20/20	Low review scope from cached public metadata (1 linked issue).
Validation posture	❌ 5/25	Preflight is holding this PR: the review lane is unavailable, so it is not ready for automated review.
Contributor workload	✅ 10/10	Author activity: 318 registered-repo PR(s), 186 merged, 9 issue(s).
Contributor context	✅ Confirmed Gittensor contributor	bohdansolovie; Gittensor profile; 318 PR(s), 9 issue(s).
Gate result	✅ Passing	No configured blocker found.

Review context

• Author: bohdansolovie
• Role context: outside_contributor
• Public audience mode: oss maintainer
• Lane context: Repository registration is not available in the local Gittensory cache.
• Public profile languages: Python, C++, JavaScript
• Official Gittensor activity: 318 PR(s), 9 issue(s).
• PR-specific overlap: none found.

Contributor next steps

• Await review-lane availability.
• Refresh registry data or choose a registered active repo.

Signal definitions

• Related work = same linked issue, overlapping active PRs, or title/path similarity.
• Change scope = cached public metadata such as size labels, draft state, and review-burden hints.
• Validation posture = whether the PR provides enough public validation/test evidence for maintainer review.
• Contributor workload = public contributor activity and cleanup pressure, not a repo-wide quality failure.
• Contributor context = public GitHub/Gittensor identity context; non-Gittensor status is not a blocker.

_{🟩 Safe / merged · 🟦 Advisory · 🟨 Held for review · 🟥 Blocked / closed}

---

💰 Earn for open-source contributions like this. Gittensor lets GitHub contributors earn for the work they already do — register to start earning →.

Checked by Gittensory, a quiet PR intelligence layer for OSS maintainers.

• Re-run Gittensory review

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@1fbe48a). Learn more about missing BASE report.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3541   +/-   ##
=======================================
  Coverage        ?   93.10%           
=======================================
  Files           ?      302           
  Lines           ?    31504           
  Branches        ?    11504           
=======================================
  Hits            ?    29333           
  Misses          ?     1517           
  Partials        ?      654           

Files with missing lines	Coverage Δ
src/review/enrichment-analyzer-names.ts	100.00% <ø> (ø)

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[loopover-orb]

Gittensory approves — the gate is satisfied and CI is green.