npm-why-slow

🔍 Diagnose slow npm/pnpm/yarn installations

A CLI tool that instruments your package manager to identify installation bottlenecks. Find out if your slow installs are caused by network latency, disk I/O, or postinstall scripts.

Installation

npm i @codimow/npm-why-slow

Usage

# Analyze your next install
npm-why-slow install

# Pass flags to the underlying package manager
npm-why-slow install -- --dry-run

# View help
npm-why-slow --help

Example Output

🔍 Detecting package manager...
✓ Detected: npm
🚀 Running npm install...

📊 Analysis Report
-------------------
Package Manager: npm
Total Time:      12.34s
Network Time:    8.21s
IO/Extract Time: 2.45s

! High network usage detected. Check your connection or registry proxy.

Features

• Auto-detection of npm, pnpm, yarn, or bun
• Timing breakdown for network, extraction, and script phases
• Actionable warnings when bottlenecks are detected
• Effect-TS powered for robust async handling

How It Works

1. Detects your package manager from lockfiles
2. Runs install with verbose logging enabled
3. Parses output in real-time to extract timing data
4. Generates a summary report with actionable insights

Development

# Install dependencies
npm install

# Build
npm run build

# Run tests
npm test

# Run locally
node dist/bin.js install

Tech Stack

• TypeScript 5.x with strict mode
• Effect-TS for functional programming
• Commander.js for CLI
• Vitest for testing
• tsup for bundling

License

ISC