feat(rees): add error-swallow analyzer for empty catch blocks (#2014)

[RealDiligent]

Summary

• Add REES errorSwallow local analyzer for empty/unused catch blocks and return-null swallow patterns in JS/TS and Python patches.
• Fix review blockers from feat(rees): add error-swallow analyzer for empty catch blocks (#2014) #3516: multiline JS catch collection, accurate hunk line numbers (context rows), immediate-next Python body line, optional-catch with code not flagged.

Closes #2014
Part of #1499

Supersedes #3516 (auto-closed for line-local scanning defects).

Test plan

• review-enrichment: npm run build && npm run metadata:check
• node --test test/error-swallow.test.ts test/analyzer-registry.test.ts (14/14 pass)
• Root npm run typecheck
• Multiline JS catch, context-hunk line numbers, Python adjacency tests added

[superagent-security]

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

[loopover-orb]

Caution

🟥🟥🟥🟥🟥🟥🟥🟥🟥🟥🟥🟥

🛑 Gittensory review result - reject/close recommended

_{Review updated: 2026-07-05 15:40:05 UTC}

10 files · 1 AI reviewer · 1 blocker · readiness 80/100 · CI pending · blocked

🛑 Suggested Action - Reject/Close

• AI reviewers agree on a likely critical defect: review-enrichment/src/analyzers/error-swallow.ts:42 uses `\b${binding}\\b` semantics for all catch bindings, but `$` is a valid JS identifier character and not a regex word character, so `catch ($err) { handle($err)
• }` is misreported as `unused-binding`
• change the binding check to use identifier-boundary lookarounds, e.g. ``const escaped = binding.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")
• if (binding && new RegExp(`(?<![A-Za-z0-9_$])${escaped}(?![A-Za-z0-9_$])`).test(body)) return true
• `` or tell me why `$` bindings are intentionally unsupported. — Resolve the flagged defect, or override if the AI reviewers are mistaken, then re-run the gate.

Review summary
This adds the requested REES analyzer and wires it through the registry, metadata, rendering, UI list, and analyzer-name allowlist, with tests for the main JS/TS and Python patch paths. The issue link is present and the generated metadata surfaces are updated consistently. I found one reachable correctness problem in the analyzer’s binding-use detection for valid JavaScript catch identifiers containing `$`, which can produce false positive unused-binding findings.

Blockers

• review-enrichment/src/analyzers/error-swallow.ts:42 uses `\b${binding}\\b` semantics for all catch bindings, but `$` is a valid JS identifier character and not a regex word character, so `catch ($err) { handle($err); }` is misreported as `unused-binding`; change the binding check to use identifier-boundary lookarounds, e.g. ``const escaped = binding.replace(/[.*+?^${}()|[\]\\]/g, "\\$&"); if (binding && new RegExp(`(?<![A-Za-z0-9_$])${escaped}(?![A-Za-z0-9_$])`).test(body)) return true;`` or tell me why `$` bindings are intentionally unsupported.

Nits — 5 non-blocking

• nit: review-enrichment/src/analyzers/error-swallow.ts:92 only looks at the immediate next added Python line, so multi-line `except Exception as e:` bodies that use/log the binding after a first setup line can be reported as `unused-binding`; if that is an intentional shallow heuristic, add a test or docs note so the analyzer contract is explicit.
• nit: review-enrichment/src/analyzers/error-swallow.ts:57 treats any `.error(` or `.warn(` call as logging even when it is unrelated to the caught error, which is fine as a low-noise heuristic but should have a targeted test because it defines the analyzer’s false-negative posture.
• Add regression coverage in review-enrichment/test/error-swallow.test.ts for `$`-prefixed and `$`-suffixed JS catch bindings that are actually referenced.
• Add one Python test that documents the chosen behavior for a multi-line `except` body where the first added statement does not mention the binding but a later added statement logs or rethrows it.
• Consider sharing the limits values from the analyzer descriptor source when generating review-enrichment/analyzer-metadata.json and apps/gittensory-ui/src/lib/rees-analyzers.ts, so the three copies cannot drift silently.

Why this is blocked

• review-enrichment/src/analyzers/error-swallow.ts:42 uses `\b${binding}\\b` semantics for all catch bindings, but `$` is a valid JS identifier character and not a regex word character, so `catch ($err) { handle($err); }` is misreported as `unused-binding`; change the binding check to use identifier-boundary lookarounds, e.g. ``const escaped = binding.replace(/[.*+?^${}()|[\]\\]/g, "\\$&"); if (binding && new RegExp(`(?<![A-Za-z0-9_$])${escaped}(?![A-Za-z0-9_$])`).test(body)) return true;`` or tell me why `$` bindings are intentionally unsupported.

Signal	Result	Evidence
Code review	❌ 1 blocker	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: 181 registered-repo PR(s), 37 merged, 0 issue(s).
Contributor context	✅ Confirmed Gittensor contributor	RealDiligent; Gittensor profile; 181 PR(s), 0 issue(s).
Gate result	❌ Blocking	Repo-configured hard blocker found.

Review context

• Author: RealDiligent
• Role context: outside_contributor
• Public audience mode: oss maintainer
• Lane context: Repository registration is not available in the local Gittensory cache.
• Public profile languages: not available
• Official Gittensor activity: 181 PR(s), 0 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}

---

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• Re-run Gittensory review

[loopover-orb]

Gittensory is closing this pull request on the maintainer's behalf (AI reviewers agree on a likely critical defect: review-enrichment/src/analyzers/error-swallow.ts:42 uses `\b${binding}\\b` semantics for all catch bindings, but `$` is a valid JS identifier character and not a regex word character, so `catch ($err) { handle($err); }` is misreported as `unused-binding`; change the binding check to use identifier-boundary lookarounds, e.g. ``const escaped = binding.replace(/[.*+?^${}()|[\]\\]/g, "\\$&"); if (binding && new RegExp(`(?<![A-Za-z0-9_$])${escaped}(?![A-Za-z0-9_$])`).test(body)) return true;`` or tell me why `$` bindings are intentionally unsupported.). This is an automated maintenance action — to pursue this change, please open a new pull request with the issues resolved. Closed PRs may be analyzed later to improve review accuracy, but they are not automatically reopened or re-reviewed.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.09%. Comparing base (fc021a5) to head (da972fe).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3525   +/-   ##
=======================================
  Coverage   93.09%   93.09%           
=======================================
  Files         301      301           
  Lines       31450    31450           
  Branches    11483    11483           
=======================================
  Hits        29279    29279           
  Misses       1517     1517           
  Partials      654      654           

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

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