---
name: check-error-handling
description: Validates error handling follows AppResult/AppError pattern, detects anyhow regression, ensures ErrorCode usage
---
# Check Error Handling Skill
## Purpose
Quick validation that error handling follows the unified AppResult/AppError pattern (commit b592b5e). Detects anyhow regression and ensures proper use of ErrorCode enum.
## CLAUDE.md Compliance
- ✅ Enforces structured error types (no anyhow)
- ✅ Validates ErrorCode usage
- ✅ Prevents error handling regression
## Usage
Run this skill:
- Before committing error handling changes
- Daily pre-commit validation
- After merging branches
- When reviewing error-related PRs
## Prerequisites
- ripgrep (`rg`)
## Commands
### Quick Check (Fast)
```bash
# Check for anyhow regression
echo "🔍 Checking for anyhow usage..."
# 1. Check imports (FORBIDDEN)
if rg "use anyhow::|use anyhow;" src/ --type rust --quiet; then
echo "❌ FAIL: anyhow imports detected!"
rg "use anyhow" src/ --type rust -n | head -10
exit 1
else
echo "✓ PASS: No anyhow imports"
fi
# 2. Check macro usage (FORBIDDEN)
if rg "anyhow!\(" src/ --type rust --quiet; then
echo "❌ FAIL: anyhow! macro detected!"
rg "anyhow!\(" src/ --type rust -n | head -10
exit 1
else
echo "✓ PASS: No anyhow! macro"
fi
# 3. Check AppResult usage
APPRESULT_COUNT=$(rg "AppResult<" src/ --type rust | wc -l)
echo "✓ AppResult usage: $APPRESULT_COUNT occurrences"
# 4. Check ErrorCode usage
ERRORCODE_COUNT=$(rg "ErrorCode::" src/ --type rust | wc -l)
echo "✓ ErrorCode usage: $ERRORCODE_COUNT occurrences"
echo ""
echo "✅ Error handling check PASSED"
```
### Comprehensive Check
```bash
#!/bin/bash
set -e
echo "🔍 Comprehensive Error Handling Check"
echo "======================================"
# 1. Anyhow Imports
echo ""
echo "1. Checking for anyhow imports..."
ANYHOW_IMPORTS=$(rg "use anyhow" src/ --type rust | wc -l)
if [ "$ANYHOW_IMPORTS" -gt 0 ]; then
echo "❌ Found $ANYHOW_IMPORTS anyhow imports:"
rg "use anyhow" src/ --type rust -n | head -10
exit 1
else
echo "✓ No anyhow imports"
fi
# 2. Anyhow Macro
echo ""
echo "2. Checking for anyhow! macro..."
if rg "anyhow!\(" src/ --type rust --quiet; then
echo "❌ anyhow! macro usage detected:"
rg "anyhow!\(" src/ --type rust -n
exit 1
else
echo "✓ No anyhow! macro"
fi
# 3. Context Method
echo ""
echo "3. Checking for .context() method..."
CONTEXT_COUNT=$(rg "\.context\(\"" src/ --type rust | wc -l)
if [ "$CONTEXT_COUNT" -gt 0 ]; then
echo "⚠️ Warning: Found $CONTEXT_COUNT .context() usages (prefer .map_err())"
rg "\.context\(" src/ --type rust -n | head -5
else
echo "✓ No .context() usage"
fi
# 4. AppResult Usage
echo ""
echo "4. Validating AppResult usage..."
APPRESULT_COUNT=$(rg "AppResult<" src/ --type rust | wc -l)
if [ "$APPRESULT_COUNT" -lt 100 ]; then
echo "⚠️ Warning: Only $APPRESULT_COUNT AppResult usages (expected >100)"
else
echo "✓ AppResult usage: $APPRESULT_COUNT"
fi
# 5. ErrorCode Usage
echo ""
echo "5. Validating ErrorCode usage..."
ERRORCODE_COUNT=$(rg "ErrorCode::" src/ --type rust | wc -l)
echo "✓ ErrorCode usage: $ERRORCODE_COUNT"
# Most common error codes
echo ""
echo "Top ErrorCodes:"
rg "ErrorCode::" src/ --type rust -o | sort | uniq -c | sort -rn | head -5
# 6. Error Type Exports
echo ""
echo "6. Checking error module exports..."
if rg "pub use.*AppError|pub use.*AppResult|pub use.*ErrorCode" src/lib.rs --type rust --quiet; then
echo "✓ Error types exported from lib.rs"
else
echo "⚠️ Error types may not be exported"
fi
# 7. Cargo.toml Check
echo ""
echo "7. Checking Cargo.toml..."
if rg "^anyhow\s*=" Cargo.toml --quiet; then
echo "⚠️ anyhow in main dependencies (should be dev-dependencies only)"
else
echo "✓ anyhow not in main dependencies"
fi
echo ""
echo "✅ Comprehensive error handling check PASSED"
```
## Success Criteria
- ✅ Zero `use anyhow` imports in src/
- ✅ Zero `anyhow!()` macro usage
- ✅ AppResult usage > 100 occurrences
- ✅ ErrorCode usage present
- ✅ Error types exported from lib.rs
## Expected Output (Success)
```
🔍 Checking for anyhow usage...
✓ PASS: No anyhow imports
✓ PASS: No anyhow! macro
✓ AppResult usage: 287 occurrences
✓ ErrorCode usage: 412 occurrences
✅ Error handling check PASSED
```
## Failure Example
```
🔍 Checking for anyhow usage...
❌ FAIL: anyhow imports detected!
src/new_feature.rs:5:use anyhow::{anyhow, Result};
src/new_feature.rs:23: return Err(anyhow!("Something failed"));
```
## Fixing Violations
### Replace anyhow import
```rust
// ❌ Before
use anyhow::{anyhow, Context, Result};
// ✅ After
use crate::errors::{AppError, AppResult, ErrorCode};
```
### Replace anyhow! macro
```rust
// ❌ Before
return Err(anyhow!("Database connection failed"));
// ✅ After
return Err(AppError::new(
ErrorCode::DatabaseError,
"Database connection failed".to_string()
));
```
### Replace .context() method
```rust
// ❌ Before
let user = db.get_user(id).context("Failed to fetch user")?;
// ✅ After
let user = db.get_user(id)
.map_err(|e| AppError::new(
ErrorCode::DatabaseError,
format!("Failed to fetch user {}: {}", id, e)
))?;
```
## Integration with Git Hooks
### Pre-Commit Hook
Add to `.git/hooks/pre-commit`:
```bash
#!/bin/bash
# Check staged Rust files for anyhow usage
if git diff --cached --name-only | grep -q "\.rs$"; then
if git diff --cached | grep -q "use anyhow"; then
echo "❌ ERROR: anyhow import detected in staged files!"
echo "Use AppResult and AppError instead."
echo ""
echo "Run: .claude/skills/check-error-handling.md"
exit 1
fi
fi
```
## CI/CD Integration
### GitHub Actions
```yaml
# .github/workflows/error-handling.yml
name: Error Handling Check
on: [push, pull_request]
jobs:
check-error-handling:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Install ripgrep
run: sudo apt-get install -y ripgrep
- name: Check for anyhow usage
run: |
if rg "use anyhow::|anyhow!\(" src/ --type rust --quiet; then
echo "❌ anyhow usage detected - use AppResult instead"
rg "use anyhow" src/ --type rust -n
exit 1
fi
echo "✓ Error handling check passed"
```
## Related Files
- `src/errors.rs` - ErrorCode and AppError definitions
- `src/lib.rs` - Error type exports
- Commit b592b5e - Error handling migration
## Related Agents
- `error-handling-guardian.md` - Comprehensive error validation
## Troubleshooting
**Issue:** False positive in test files
```bash
# Exclude tests from check
rg "use anyhow" src/ --type rust | grep -v "^tests/"
```
**Issue:** Need to use anyhow in tests
```bash
# Anyhow is OK in tests and bin files
# This check only scans src/ production code
```
**Issue:** .context() detected but it's not from anyhow
```bash
# Check if it's actually anyhow
rg "\.context\(" src/file.rs -B 5 | grep "use anyhow"
```
## Quick Reference
```bash
# One-line check
rg "use anyhow|anyhow!\(" src/ --type rust && echo "FAIL" || echo "PASS"
# Check specific file
rg "use anyhow" src/new_feature.rs --type rust
# Count error patterns
echo "AppResult: $(rg 'AppResult<' src/ --type rust | wc -l)"
echo "ErrorCode: $(rg 'ErrorCode::' src/ --type rust | wc -l)"
```
