Vercel Plugin Eval

---
name: vercel-plugin-eval
description: Run live eval sessions against the vercel-plugin to verify hook behavior, skill injection, dedup correctness, and coverage. Launches real Claude Code sessions via WezTerm, monitors debug logs, and produces a structured coverage report.
---

# Plugin Eval

Launch real Claude Code sessions with the plugin installed, monitor debug logs in real-time, and verify every hook fires correctly with proper dedup.

## DO NOT (Hard Rules)

- **DO NOT** use `claude --print` or `-p` — hooks don't fire, no files created
- **DO NOT** use `--dangerously-skip-permissions`
- **DO NOT** create projects in `/tmp/` — always use `~/dev/vercel-plugin-testing/`
- **DO NOT** manually wire hooks or create `settings.local.json` — use `npx add-plugin`
- **DO NOT** set `CLAUDE_PLUGIN_ROOT` manually
- **DO NOT** use `bash -c` in WezTerm — use `/bin/zsh -ic`
- **DO NOT** use full path to claude — use the `x` alias
- **DO NOT** write eval scripts — do everything as Bash tool calls in the conversation

**Copy the exact commands below. Do not improvise.**

## Quick Start

**Always append a timestamp** to directory names so reruns don't overwrite old projects:

```bash
# 1. Create test dir & install plugin (with timestamp)
TS=$(date +%Y%m%d-%H%M)
SLUG="my-eval-$TS"
mkdir -p ~/dev/vercel-plugin-testing/$SLUG
cd ~/dev/vercel-plugin-testing/$SLUG
npx add-plugin https://github.com/vercel/vercel-plugin -s project -y

# 2. Launch session via WezTerm
wezterm cli spawn --cwd /Users/johnlindquist/dev/vercel-plugin-testing/$SLUG -- /bin/zsh -ic \
  "unset CLAUDECODE; VERCEL_PLUGIN_LOG_LEVEL=debug x '<PROMPT>' --settings .claude/settings.json; exec zsh"

# 3. Find debug log (wait ~25s for session start)
find ~/.claude/debug -name "*.txt" -mmin -2 -exec grep -l "$SLUG" {} +
```

## What to Monitor

### Hook firing (all 8 registered hooks)

```bash
LOG=~/.claude/debug/<session-id>.txt

# SessionStart (3 hooks)
grep "SessionStart.*success" "$LOG"

# PreToolUse skill injection
grep -c "executePreToolHooks" "$LOG"        # total calls
grep -c "provided additionalContext" "$LOG"  # injections

# UserPromptSubmit
grep "UserPromptSubmit.*success" "$LOG"

# PostToolUse validate + shadcn font-fix
grep "posttooluse-validate.*provided" "$LOG"
grep "PostToolUse:Bash.*success" "$LOG"

# SessionEnd cleanup
grep "SessionEnd" "$LOG"
```

### Dedup correctness (the key metric)

```bash
TMPDIR=$(node -e "import {tmpdir} from 'os'; console.log(tmpdir())" --input-type=module)
CLAIMDIR="$TMPDIR/vercel-plugin-<session-id>-seen-skills.d"

# Claim files = one per skill, atomic O_EXCL
ls "$CLAIMDIR"

# Compare: injections should equal claims
inject_meta=$(grep -c "skillInjection:" "$LOG")
claims=$(ls "$CLAIMDIR" 2>/dev/null | wc -l | tr -d ' ')
echo "Injections: $((inject_meta / 3)) | Claims: $claims"
```

`skillInjection:` appears 3x per actual injection in the debug log (initial check, parsed, success). Divide by 3.

### PostToolUse validate quality

Look for real catches — API key bypass, outdated models, wrong patterns:

```bash
grep "VALIDATION" "$LOG" | head -10
```

## Scenario Design

Describe **products and features**, never name specific technologies. Let the plugin infer which skills to inject. Always end prompts with: "Link the project to my vercel-labs team so we can deploy it later. Skip any planning and just build it. Get the dev server running."

### Coverage targets by scenario type

| Scenario Type | Skills Exercised |
|--------------|-----------------|
| AI chat app | ai-sdk, ai-gateway, nextjs, ai-elements |
| Durable workflow | workflow, ai-sdk, vercel-queues |
| Monorepo | turborepo, turbopack, nextjs |
| Edge auth + routing | routing-middleware, auth, sign-in-with-vercel |
| Chat bot (multi-platform) | chat-sdk, ai-sdk, vercel-storage |
| Feature flags + CRM | vercel-flags, vercel-queues, ai-sdk |
| Email pipeline | email, satori, ai-sdk, vercel-storage |
| Marketplace/payments | payments, marketplace, cms |
| Kitchen sink | micro, ncc, all niche skills |

### Hard-to-trigger skills (8 of 44)

These need explicit technology references in the prompt because agents don't naturally reach for them:

- `ai-elements` — say "use the AI Elements component registry"
- `v0-dev` — say "generate components with v0"
- `vercel-firewall` — say "use Vercel Firewall for rate limiting"
- `marketplace` — say "publish to the Vercel Marketplace"
- `geist` — say "install the geist font package"
- `json-render` — name files `components/chat-*.tsx`

## Coverage Report

Write results to `.notes/COVERAGE.md` with:

1. **Session index** — slug, session ID, unique skills, dedup status
2. **Hook coverage matrix** — which hooks fired in which sessions
3. **Skill injection table** — which of the 44 skills triggered
4. **Dedup stats** — injections vs claims per session
5. **Issues found** — bugs, pattern gaps, validation findings

## Cleanup

```bash
rm -rf ~/dev/vercel-plugin-testing
```