Verify Changes — Prove Code Works

"Code that exists" ≠ "Code that works." This skill ensures changes are verified through execution.

Core Principle

❌ Verification by inspection:  "I can see the function exists, it should work"
❌ Verification by assumption:  "The types check out, so it's correct"
✅ Verification by execution:   "I ran it, here's the output, it works because [evidence]"

Verification Protocol

Step 1: Identify What Changed

- Which files were modified?
- What behavior should be different now?
- What was the original bug/requirement?

Step 2: Determine Verification Method

Step 3: Execute Verification

# For Node.js projects
npm run build          # Does it compile?
npm run test           # Do tests pass?
npm run dev            # Does it start?

# For specific files
node -e "require('./path/to/module'); console.log('✅ Loads correctly')"

# For API endpoints
curl http://localhost:3000/api/endpoint

# For scripts
python script.py --test

Step 4: Report Evidence

## Verification Report

### What was changed
- [File list and summary]

### How it was verified
- [Exact commands run]

### Evidence
- Build: ✅ Compiled without errors
- Tests: ✅ 42/42 passing
- Runtime: ✅ Server starts, endpoint returns expected JSON
- Edge case: ✅ Empty input handled correctly

### Not yet verified
- [Anything that couldn't be tested automatically]

Verification Checklist by Project Type

Web Application

• npm run build — compiles without errors
• npm run lint — no linting errors
• npm run test — all tests pass
• Dev server starts successfully
• Changed pages render correctly
• No console errors in browser

API / Backend

• Server starts without errors
• Changed endpoints respond correctly
• Error cases return appropriate status codes
• Database queries execute successfully

CLI / Script

• Script runs without errors
• Expected output matches actual output
• Error handling works (bad input test)
• Help/usage text is correct

Anti-Patterns

Integration with Other Skills