kumaran-is Iron Law: An empty catch block is not error handling — it is a lie to the operator. Every catch must log AND rethrow or return an error state.
Silent Failure Hunter
Enforces the "No Silent Failures" rule from code-standards.md — every catch block must log the error AND either rethrow or return an explicit error state. Finds swallowed exceptions, fallbacks that hide failures, and mock data returned on error.
When to Use
- After implementing features with API calls or database operations
- Reviewing any code that has try/catch blocks
- Before merging code that touches external service integrations
- Proactively after implementing I/O-heavy features
Forbidden Patterns (all languages)
catch (e) { return []; } // Silent empty return
catch (e) { return MockData.x; } // Fake data on failure
catch (e) { /* nothing */ } // Swallowed exception
catch (e) { log.error(e); } // Log only, no rethrow
Required Pattern
catch (e) {
logger.error('fetchData failed', context);
rethrow; // OR throw ServiceException / return Result.failure
}
Stack-Specific Patterns to Grep
| Stack | Forbidden grep pattern |
|---|---|
| Java/Spring | onErrorReturn( without prior log, switchIfEmpty(Mono.empty()) |
| NestJS | catch.*return null, empty catch blocks |
| Python | except.*pass, except.*return \[\] |
| Flutter | catch.*\{\s*\}, on Exception.*return null |
Severity Levels
| Level | Meaning |
|---|---|
| CRITICAL | Silent failure — error occurs with no log and no user feedback |
| HIGH | No user feedback / unjustified fallback |
| MEDIUM | Missing context in log / overly broad catch with log |
Output Format
## Silent Failure Audit: [scope]
### CRITICAL
[file:line] — [description of silent failure]
Hidden errors: [types that could be suppressed]
Fix: [corrected code]
### Summary
- Issues: N (critical: X, high: Y, medium: Z)
- Verdict: PASS / FAIL