mohyung

Snapshot and restore node_modules as a single SQLite file.

Why?

• Single file backup: Manage as one .db file instead of tens of thousands of files
• Fast restoration: Quick node_modules restoration with compression + deduplication
• Version control friendly: SQLite format enables binary diff
• Content-addressable: Identical files are stored only once (deduplication)

Installation

npm install -g mohyung
# or
pnpm add -g mohyung

Usage

pack - Snapshot node_modules into DB

mohyung pack [options]

Options:
  -s, --source <path>       node_modules path (default: "./node_modules")
  -o, --output <path>       output DB file path (default: "./node_modules.db")
  -c, --compression <level> compression level 1-9 (default: "6")
  --include-lockfile        include package-lock.json hash

Examples:

# Basic usage
mohyung pack

# Custom paths
mohyung pack -s ./my-project/node_modules -o ./backup.db

# Maximum compression
mohyung pack -c 9

unpack - Restore node_modules from DB

mohyung unpack [options]

Options:
  -i, --input <path>   input DB file path (default: "./node_modules.db")
  -o, --output <path>  output directory (default: "./node_modules")
  -f, --force          overwrite existing node_modules

Examples:

# Basic restoration
mohyung unpack

# Force overwrite
mohyung unpack -f

# Restore to different location
mohyung unpack -o ./restored_modules

status - Compare DB with current state

mohyung status [options]

Options:
  --db <path>               DB file path (default: "./node_modules.db")
  -n, --node-modules <path> node_modules path (default: "./node_modules")

Examples:

mohyung status

Output:

┌─ Status ─────────────────────────────┐
│ Unchanged: 12,345                    │
│ Modified: 3                          │
│ Only in DB: 1                        │
│                                      │
│ Modified files:                      │
│   M lodash/index.js                  │
│   M express/lib/router.js            │
└──────────────────────────────────────┘

DB Schema

┌─────────────────────────────────────────────────────────────┐
│                        SQLite DB                            │
├─────────────┬───────────────────────────────────────────────┤
│  metadata   │ created_at, node_version, schema_version, ... │
├─────────────┼───────────────────────────────────────────────┤
│  packages   │ id, name, version, path                       │
├─────────────┼───────────────────────────────────────────────┤
│  blobs      │ hash (PK), content (compressed), sizes        │
├─────────────┼───────────────────────────────────────────────┤
│  files      │ package_id, relative_path, blob_hash, mode    │
└─────────────┴───────────────────────────────────────────────┘

Content-addressable Storage:

• Uses SHA-256 hash of file content as key
• Identical files are stored only once
• zlib compression for storage efficiency

Requirements

• Node.js >= 18.0.0
• Supports npm, yarn, and pnpm

Library Usage

import { pack, unpack, status, Store } from 'mohyung'

// Pack
await pack({
  source: './node_modules',
  output: './node_modules.db',
  compressionLevel: 6,
})

// Unpack
await unpack({
  input: './node_modules.db',
  output: './node_modules',
  force: true,
})

// Status
const result = await status({
  db: './node_modules.db',
  nodeModules: './node_modules',
})

console.log(result.unchanged, result.modified, result.onlyInDb)

Development

# Install dependencies
pnpm install

# Development mode (watch)
pnpm dev

# Build
pnpm build

# Test
pnpm test

# Type check
pnpm typecheck

License

MIT