bun-n2b

name	bun-n2b
description	Audit ou migrate Node.js → Bun natif via le CLI n2b. TRIGGER when: user says 'migrate to bun', 'node to bun', 'bun-native', 'n2b audit', 'check for node patterns', 'rewrite to bun-native APIs', or asks about replacing fs/child_process/node-fetch with Bun equivalents. Also triggers after a major refactor where Node APIs are used.
allowed-tools	Read, Write, Edit, Bash, Glob, Grep, Agent
model	inherit

n2b — Node.js → Bun-native migration skill

Scan et réécrit automatiquement les usages Node legacy vers les APIs Bun natives. Binaire détecté via $PATH, jamais hardcodé.

Invocation patterns

# Détection env (toujours en premier)
N2B="$(command -v n2b)" || { echo "n2b absent"; exit 1; }
PROJECT_ROOT="$(git rev-parse --show-toplevel 2>/dev/null || echo "$PWD")"
REPORTS_DIR="${PROJECT_ROOT}/bun/reports"; mkdir -p "$REPORTS_DIR"

Audit (non-mutating)

# Top findings
$N2B "$PROJECT_ROOT" --agent --report jsonl \
  --ignore 'node_modules/**' --ignore '.next/**' --ignore 'dist/**' --ignore '**/generated/**' \
| tee "$REPORTS_DIR/n2b-baseline.jsonl" \
| jq -r '.rule_id' | sort | uniq -c | sort -rn | head

# Rapport MD lisible
$N2B "$PROJECT_ROOT" --report md > "$REPORTS_DIR/n2b-baseline.md"

Fix scopé

# Safe (jamais sur tout le repo)
$N2B scripts/ --fix                   # cli/*, imports/node-prefix, ci/*, shebang/*, husky/*

# Aggressive (scope étroit, confirmation avant)
$N2B scripts/ --fix --aggressive      # + api/* templateables (fs.readFileSync, Buffer, …)

Gate post-fix (auto-détectée)

cd "$PROJECT_ROOT"
bun install --frozen-lockfile
jq -e '.scripts.build' package.json > /dev/null && bun run build
jq -e '.scripts.lint' package.json > /dev/null && bun run lint
[ -f tsconfig.json ] && bun tsc --noEmit

Catalogue règles — résumé

• Safe autofix (--fix) : cli/* (40+ règles npm/pnpm/yarn/npx), imports/node-prefix (38 builtins), ci/setup-node, shebang/node, husky/*
• Aggressive autofix (--aggressive) : api/fs-* → Bun.file/Bun.write, api/buffer-*, api/dirname-esm, api/sleep-promise, api/json-parse-readFileSync, imports/bun-native (partiel — seulement bun:*/node:*)
• Report-only (rewrite manuel) : api/execSync, api/exec, api/child-process-spawn, api/http(s)-createServer, api/crypto-createHash, api/buffer-from-base64
• SKIP : api/process-env (portabilité SSR)

Catalogue complet : ${CLAUDE_PLUGIN_ROOT}/docs/n2b/README.md ou $N2B rules --report md.

Délégation

• Scope large / cartographie → déléguer à bun-explorer
• Review du diff post-fix → bun-reviewer
• Build + deploy post-phase → bun-deployer
• Multi-phase orchestration → bun-runner avec l'agent n2b

Règles dures

1. Toujours $N2B <path>, jamais $N2B . en autofix
2. --aggressive sur scope étroit uniquement (scripts/, utilities)
3. --migrate : confirmation explicite obligatoire (supprime lockfiles rivaux)
4. 1 phase = 1 commit conventional, jamais --no-verify
5. Ignorer **/generated/**, prisma/schema.prisma, lockfiles

Pour le workflow complet multi-phases → invoquer l'agent n2b via subagent_type: n2b.