Performance testing is a crucial aspect of ensuring that your web applications run efficiently under various conditions. In this section, we will explore how to use Playwright to conduct performance testing, focusing on measuring and analyzing the performance of web applications.
Key Concepts in Performance Testing
- Load Time: The time it takes for a page to fully load.
- Response Time: The time taken for a server to respond to a request.
- Throughput: The number of requests a system can handle in a given time period.
- Resource Utilization: The usage of CPU, memory, and network resources during the test.
Setting Up Playwright for Performance Testing
Before diving into performance testing, ensure you have Playwright installed and set up in your project. If not, refer to the "Installing Playwright" section in Module 2.
Installing Additional Tools
For performance testing, you might need additional tools like lighthouse for more detailed insights. Install it using:
Writing a Basic Performance Test
Let's start by writing a simple script to measure the load time of a webpage.
Example Code
import { chromium } from 'playwright';
(async () => {
const browser = await chromium.launch();
const page = await browser.newPage();
const start = Date.now();
await page.goto('https://example.com');
const loadTime = Date.now() - start;
console.log(`Page load time: ${loadTime}ms`);
await browser.close();
})();Explanation
- Importing Playwright: We import the
chromiummodule from Playwright to launch a browser instance. - Measuring Load Time: We record the time before and after the
page.goto()function to calculate the page load time. - Output: The script logs the load time in milliseconds.
Analyzing Performance Metrics
Using Lighthouse
Lighthouse provides a comprehensive analysis of web performance. You can run it from the command line:
This command generates an HTML report with detailed performance metrics.
Key Metrics to Analyze
- First Contentful Paint (FCP): Time taken for the first piece of content to appear.
- Time to Interactive (TTI): Time taken for the page to become fully interactive.
- Speed Index: How quickly the contents of a page are visibly populated.
Practical Exercise
Task
Write a Playwright script to measure the response time of a specific API endpoint.
Solution
import { chromium } from 'playwright';
(async () => {
const browser = await chromium.launch();
const page = await browser.newPage();
const response = await page.goto('https://api.example.com/data');
const responseTime = response.timing().responseEnd - response.timing().requestStart;
console.log(`API response time: ${responseTime}ms`);
await browser.close();
})();Explanation
- Response Timing: We use the
response.timing()method to calculate the time between the request start and response end.
Common Mistakes and Tips
- Network Conditions: Simulate different network conditions using Playwright's
page.emulateNetworkConditions()to test performance under various scenarios. - Resource Monitoring: Use browser developer tools to monitor CPU and memory usage during tests.
Conclusion
In this section, we explored how to use Playwright for performance testing, focusing on measuring load and response times. By integrating tools like Lighthouse, you can gain deeper insights into your application's performance. In the next section, we will delve into visual testing with Playwright, enhancing your testing strategy further.
Playwright with TypeScript: From Beginner to Advanced
Module 1: Introduction to Playwright and TypeScript
- What is Playwright?
- Setting Up Your Development Environment
- Introduction to TypeScript
- Basic TypeScript Syntax
Module 2: Getting Started with Playwright
- Installing Playwright
- Creating Your First Playwright Script
- Understanding Playwright's Core Concepts
- Running Playwright Tests
Module 3: Playwright and TypeScript Basics
- Writing Tests in TypeScript
- Using TypeScript Interfaces and Types
- Debugging Playwright Tests
- Handling Asynchronous Code
Module 4: Advanced Playwright Features
- Working with Selectors
- Handling Multiple Pages and Frames
- Network Interception and Mocking
- Emulating Devices and Geolocation
Module 5: Test Automation Strategies
- Organizing Tests and Test Suites
- Using Fixtures and Hooks
- Parallel Test Execution
- Continuous Integration with Playwright
Module 6: Advanced TypeScript Techniques
- Generics in TypeScript
- Advanced TypeScript Types
- TypeScript Decorators
- TypeScript and Playwright Best Practices
Module 7: Real-World Playwright Applications
- End-to-End Testing with Playwright
- Visual Testing with Playwright
- Performance Testing with Playwright
- Case Study: Implementing Playwright in a Project