What is Puppeteer? What are its main features and use cases? - 面试题

Puppeteer is a Node.js library that provides a high-level API to control headless Chrome or Chromium over the DevTools Protocol. It can also be configured to use full (non-headless) Chrome or Chromium.

Core Features:

Headless Browser Control: Puppeteer can run Chrome in headless mode, meaning the browser interface doesn't display, but all functionality remains available.
Page Operations: Can generate screenshots and PDFs of pages, crawl SPAs (Single Page Applications), and scrape content.
Automated Testing: Can simulate user actions like clicking, typing text, navigation, etc., making it ideal for automated testing.
Performance Analysis: Can capture timeline traces to help diagnose performance issues.
Network Interception: Can intercept and modify network requests for testing and debugging.

Basic Usage Example:

javascript
const puppeteer = require('puppeteer');

(async () => {
  // Launch browser
  const browser = await puppeteer.launch();
  
  // Create new page
  const page = await browser.newPage();
  
  // Navigate to URL
  await page.goto('https://example.com');
  
  // Take screenshot
  await page.screenshot({ path: 'example.png' });
  
  // Close browser
  await browser.close();
})();

Main Use Cases:

Web Scraping: Scrape dynamically rendered web content
Automated Testing: E2E testing, UI testing
PDF Generation: Convert web pages to PDF documents
Performance Monitoring: Analyze page load performance
Screenshot Services: Batch generate webpage screenshots

Differences from Selenium:

Puppeteer uses Chrome DevTools Protocol directly, making it faster
Selenium supports multiple browsers, Puppeteer mainly supports Chrome/Chromium
Puppeteer has a simpler API with a lower learning curve
Puppeteer has better support for modern web technologies