How does npm compare to pnpm and Bun and which package manager should you choose? - 面试题

In addition to npm and Yarn, there are other popular JavaScript package managers like pnpm and Bun. Understanding their features and selection criteria is important for project decision-making.

pnpm

Basic Introduction

pnpm is a fast, disk-space-saving package manager that uses hard links and symbolic links to manage dependencies.

Core Features

1. Save Disk Space

pnpm uses content-addressable storage, where all packages are stored in a global store and referenced via hard links:

shell
~/.pnpm-store/
├── v3/
│   └── files/
│       └── 00/
│           └── 00a1b2c3d4.../  # Actual package files

project/
└── node_modules/
    └── .pnpm/
        └── package@1.0.0/
            └── node_modules/
                └── package/  # Hard link to global store

2. Strict Dependency Isolation

pnpm ensures packages can only access their declared dependencies:

javascript
// package-a can only access its declared dependencies
// Cannot access package-b's dependencies

3. Fast Installation

pnpm's installation speed is faster than npm and Yarn:

Package Manager	Installation Time (1000+ dependencies)
npm 6	~120s
npm 7+	~60s
Yarn 1	~45s
Yarn 2+	~40s
pnpm	~30s

pnpm Commands

bash
# Install pnpm
npm install -g pnpm

# Install dependencies
pnpm install

# Add dependency
pnpm add <package>

# Add dev dependency
pnpm add -D <package>

# Remove dependency
pnpm remove <package>

# Update dependencies
pnpm update

# Run script
pnpm run <script>

# Global install
pnpm add -g <package>

pnpm Workspaces

json
{
  "name": "my-monorepo",
  "version": "1.0.0",
  "private": true,
  "scripts": {
    "build": "pnpm -r build",
    "test": "pnpm -r test"
  }
}

bash
# Run command in all workspaces
pnpm -r build
pnpm --recursive build

# Run command in specific workspace
pnpm --filter package-a build

pnpm Configuration

bash
# Set store location
pnpm config set store-dir ~/.pnpm-store

# Set registry
pnpm config set registry https://registry.npmmirror.com

# View configuration
pnpm config list

Bun

Basic Introduction

Bun is a modern JavaScript runtime and package manager with built-in package manager, test runner, and bundler.

Core Features

1. Extremely Fast Installation

Bun's installation speed is much faster than other package managers:

Package Manager	Installation Time (1000+ dependencies)
npm 7+	~60s
Yarn 2+	~40s
pnpm	~30s
Bun	~10s

2. Built-in Toolchain

Bun includes multiple built-in tools:

Package manager
Test runner
Bundler
Server

3. Node.js Compatible

Bun is compatible with most Node.js APIs and npm packages.

Bun Commands

bash
# Install Bun
curl -fsSL https://bun.sh/install | bash

# Install dependencies
bun install

# Add dependency
bun add <package>

# Add dev dependency
bun add -d <package>

# Remove dependency
bun remove <package>

# Update dependencies
bun update

# Run script
bun run <script>

# Run file
bun run index.js

Bun Workspaces

json
{
  "name": "my-monorepo",
  "version": "1.0.0",
  "private": true,
  "workspaces": [
    "packages/*"
  ]
}

bash
# Run command in all workspaces
bun run build --filter "*"

Package Manager Comparison

Feature Comparison

Feature	npm	Yarn	pnpm	Bun
Installation Speed	Medium	Fast	Very Fast	Extremely Fast
Disk Space	High	High	Low	Medium
Dependency Isolation	Low	Medium	High	Medium
Workspace Support	npm 7+	Yarn 1+	Supported	Supported
Plug'n'Play	No	Yarn 2+	No	No
Hard Links	No	No	Yes	No
Built-in Tools	No	No	No	Yes
Ecosystem	Largest	Large	Medium	Small

Use Case Comparison

npm

Use Cases:

New projects without special requirements
Team already familiar with npm
Need maximum ecosystem support
CI/CD environments (default support)

Advantages:

Installed with Node.js
Largest ecosystem
Good documentation and community support
npm 7+ performance is sufficient

Disadvantages:

High disk space usage
Weak dependency isolation

Yarn

Use Cases:

Large monorepos
Need offline support
Better user experience
Need Plug'n'Play functionality

Advantages:

Better workspace support
Mature offline mode
Better user experience
Rich plugin ecosystem

Disadvantages:

Requires separate installation
Yarn 2+ has steeper learning curve

pnpm

Use Cases:

Limited disk space
Need strict dependency isolation
Need fast installation
Large monorepos

Advantages:

Extremely low disk space usage
Strict dependency isolation
Very fast installation speed
Good workspace support

Disadvantages:

Relatively smaller ecosystem
Hard links may have issues on some systems

Bun

Use Cases:

Need extremely fast installation speed
New projects, can try new technologies
Need built-in toolchain
Performance-sensitive projects

Advantages:

Extremely fast installation speed
Built-in toolchain
Node.js compatible
Modern design

Disadvantages:

Smaller ecosystem
Relatively new, stability to be verified
Limited community support

Migration Guide

Migrating from npm to pnpm

bash
# 1. Install pnpm
npm install -g pnpm

# 2. Delete node_modules and lock file
rm -rf node_modules package-lock.json

# 3. Install dependencies
pnpm install

# 4. Update scripts (if needed)
# npm run -> pnpm run
# npm install -> pnpm install

Migrating from Yarn to pnpm

bash
# 1. Install pnpm
npm install -g pnpm

# 2. Delete node_modules and lock file
rm -rf node_modules yarn.lock

# 3. Install dependencies
pnpm install

# 4. Update scripts
# yarn -> pnpm

Migrating from npm to Bun

bash
# 1. Install Bun
curl -fsSL https://bun.sh/install | bash

# 2. Delete node_modules and lock file
rm -rf node_modules package-lock.json

# 3. Install dependencies
bun install

# 4. Update scripts
# npm run -> bun run

Best Practices

1. Choose the Right Package Manager

Considerations:

Project scale and complexity
Team familiarity
Performance requirements
Disk space limitations
CI/CD environment support

2. Lock Package Manager

Explicitly specify the package manager used in the project:

json
{
  "scripts": {
    "preinstall": "npx only-allow pnpm"
  }
}

3. Use CI/CD Caching

yaml
# GitHub Actions - pnpm
- uses: pnpm/action-setup@v2
  with:
    version: 8

- uses: actions/setup-node@v3
  with:
    cache: 'pnpm'

- run: pnpm install

4. Document Choice

Document the package manager used in README:

markdown
## Installation

This project uses pnpm as the package manager.

```bash
# Install pnpm
npm install -g pnpm

# Install dependencies
pnpm install

shell

## Performance Benchmarks

### Installation Speed Test

```bash
# Test npm
time npm install

# Test Yarn
time yarn install

# Test pnpm
time pnpm install

# Test Bun
time bun install

Disk Space Test

bash
# View node_modules size
du -sh node_modules

# npm: ~1GB
# Yarn: ~1GB
# pnpm: ~300MB
# Bun: ~800MB

Future Trends

npm: Continuously improving performance and security
Yarn: Promoting Plug'n'Play and zero-install
pnpm: Improving hard links and dependency isolation
Bun: Rapid growth, may become a mainstream choice

Choosing a package manager should be based on project requirements, team preferences, and long-term maintenance considerations.