Verification Loop Skill

A comprehensive verification system for Claude Code sessions.

When to Use

Invoke this skill:

• After completing a feature or significant code change
• Before creating a PR
• When you want to ensure quality gates pass
• After refactoring

Verification Phases

Phase 1: Build Verification

set -o pipefail  # report the build's exit status, not tail's
# Check if project builds
npm run build 2>&1 | tail -20
# OR
pnpm build 2>&1 | tail -20

If build fails, STOP and fix before continuing.

Phase 2: Type Check

set -o pipefail
# TypeScript projects
npx --no-install tsc --noEmit 2>&1 | sed -n '1,30p'

# Python projects
pyright . 2>&1 | sed -n '1,30p'

Report all type errors. Fix critical ones before continuing.

Phase 3: Lint Check

Use sed to limit displayed output while consuming the whole stream. This keeps a successful linter from failing on SIGPIPE when pipefail is enabled.

set -o pipefail
# JavaScript/TypeScript
npm run lint 2>&1 | sed -n '1,30p'

# Python
ruff check . 2>&1 | sed -n '1,30p'

Phase 4: Test Suite

set -o pipefail
# Run tests with coverage
npm run test -- --coverage 2>&1 | tail -50

# Check coverage threshold
# Target: 80% minimum

Report:

• Total tests: X
• Passed: X
• Failed: X
• Coverage: X%

Phase 5: Security Scan

# Check for secrets
grep -rn "sk-" --include="*.ts" --include="*.js" . 2>/dev/null | head -10
grep -rn "api_key" --include="*.ts" --include="*.js" . 2>/dev/null | head -10

# Check for console.log
grep -rn "console.log" --include="*.ts" --include="*.tsx" src/ 2>/dev/null | head -10

Phase 6: Diff Review

# Show what changed
git diff --stat
git diff HEAD~1 --name-only

Review each changed file for:

• Unintended changes
• Missing error handling
• Potential edge cases

Output Format

After running all phases, produce a verification report:

VERIFICATION REPORT
==================

Build:     [PASS/FAIL]
Types:     [PASS/FAIL] (X errors)
Lint:      [PASS/FAIL] (X warnings)
Tests:     [PASS/FAIL] (X/Y passed, Z% coverage)
Security:  [PASS/FAIL] (X issues)
Diff:      [X files changed]

Overall:   [READY/NOT READY] for PR

Issues to Fix:
1. ...
2. ...

Continuous Mode

For long sessions, run verification every 15 minutes or after major changes:

Set a mental checkpoint:
- After completing each function
- After finishing a component
- Before moving to next task

Run: /verify

Integration with Hooks

This skill complements PostToolUse hooks but provides deeper verification. Hooks catch issues immediately; this skill provides comprehensive review.