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

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⏸️ Gittensory review result - manual review recommended

_{Review updated: 2026-07-05 16:17:53 UTC}

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

⏸️ Suggested Action - Manual Review

Review summary
Adds a correct, well-structured `errorSwallow` analyzer covering the full wiring surface: new `ErrorSwallowFinding` type, registry descriptor, render hook, `enrichment-analyzer-names.ts`, `analyzer-metadata.json`, UI metadata, and `.env.example`. The brace-balance state machine for multi-line catches is logically sound — the multi-line test correctly traces `startLine` through the patch hunk counter and `flushPending` correctly strips the opening `{` and closing `}` before calling `bodySwallowsError`. Identifier-boundary lookarounds with `[A-Za-z0-9_$]` instead of `\b` correctly handle `$`-prefixed bindings. All checks pass green and the test suite covers single-line, multi-line, Python, cap, cross-file, and public-safe-brief cases.

Nits — 5 non-blocking

• In `updatePending` and `braceBalanceFrom`, brace counting is purely character-level and doesn't skip string or template-literal contents — a `}` inside a string literal (e.g., `const msg = "closing: }";`) will prematurely decrement `depth` to 0, causing `flushPending` to evaluate an incomplete body, which can produce a false-positive `unused-binding` result for a catch that actually uses or rethrows the error; worth documenting as a known limitation alongside the existing `notes` field in the registry descriptor.
• In `scanPatchForErrorSwallow`, after `flushPending` produces a finding via `pushFinding(pending.startLine, kind)`, there is no immediate cap check — the `if (findings.length >= maxFindings) return findings` guard appears only at the bottom of the outer loop, one iteration later; the single-line path does an inline `return findings` after the cap check (`error-swallow.ts:~160`), so the multi-line flush path should mirror it to stay consistent and avoid emitting up to `maxFindings + 1` results.
• Magic numbers `25` and `2000` are inlined in `registry.ts:1087` and `apps/gittensory-ui/src/lib/rees-analyzers.ts:1016-1017`; `MAX_FINDINGS` and `MAX_LINE_CHARS` are private to `error-swallow.ts` and not exported, so any future limit adjustment requires edits in three places.
• Neither `detectErrorSwallow` nor `parseCompleteCatchLine` skips comment lines — a diff line like `// catch (e) {}` matches `CATCH_OPEN_RE` and would be flagged as `empty-catch`; low practical frequency but worth a single test case and a guard (`line.trimStart().startsWith('//')`).
• The `AbortSignal` abort path in `scanPatchForErrorSwallow` (the `throw new Error('analyzer_aborted')` branch) has no test coverage — other analyzers in this repo (e.g. `floating-promise`) include an abort-signal test; add one.

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}

---

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.09%. Comparing base (2c547b4) to head (e8f9973).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3532   +/-   ##
=======================================
  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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[JSONbored]

Merge conflicts:

This branch has conflicts that must be resolved
Use the [web editor](https://github.com/JSONbored/gittensory/pull/3532/conflicts) or the command line to resolve conflicts before continuing.

.env.example
apps/gittensory-ui/src/lib/rees-analyzers.ts
review-enrichment/analyzer-metadata.json
review-enrichment/src/analyzers/registry.ts
review-enrichment/src/render.ts
review-enrichment/src/types.ts
review-enrichment/test/analyzer-registry.test.ts
src/review/enrichment-analyzer-names.ts