Performance Testing with Cypress: A Detailed Guide

When progress web applications, ensuring they perform reliably under real-world user loads is critical. As concurrent users admission and interact with the app, execution issues like slow response multiplication or crashes can issue.

Although Cypress is wide habituate for functional testing, this guide explores how it can be adapted to support performance testing need effectively.

What is Cypress Performance Testing?

Cypress is widely used for and, but with the helper of plugins and custom utilities, it can likewise support.

By run its functionality, Cypress can monitor page load times, trail key execution metrics, and analyze application behavior under various weather. This do it a practical selection for name performance bottleneck besides.

Load Testing with Cypress

While Cypress is principally built for functional and UI testing in mod JavaScript applications, it can be extended to support through community-driven plugins.

Although Cypress doesn & # 8217; t natively support execution examination, instrument likeGoogle Lighthousecan be integrated to simulate user load and assess app performance under stress.

This allows teams to conduct basic freight and using Cypress as part of a encompassing performance testing strategy.

Using Google Lighthouse for Cypress Performance Testing

Google Lighthouse is a powerful tool integrate into Chrome that measures web execution and identifies issues such as slow burden times, ineffective images, and badly optimise code.

Key aspects about using Lighthouse with Cypress for Performance Testing:

• Lighthouse helps identify performance issues like slow load times, declamatory icon, and inefficient code.
• Easily approachable through the Lighthouse tab in Chrome DevTools.
• For more tractableness, you can use the Lighthouse CLI to run trial outside Chrome DevTools.
• Integrates Lighthouse forthwith into your Cypress exam, enabling you to run performance tryout as part of your automation suite.
• Combining Cypress and Lighthouse countenance for machine-driven performance testing alongside functional tests, ensuring logical performance across your web application.

Performance Testing with Cypress and Lighthouse

For performance essay with Cypress, use the Cypress Audit plugin in combination with Google Lighthouse.

This apparatus enables execution audits on web applications, providing key metric around page speed, load time, and overall performance. Google Lighthouse facilitate interpret these metrics and highlights area for optimisation.

Pre-requisites for Performance Testing with Cypress

Below are the pre-requisites to get started:

• Ensure that you experience a Cypress E2E project.
• Install the` cypress-audit/lighthouse `module in your projection

npm i -D cypress @ cypress-audit/lighthouse

• Add the initialization code to the` cypress.config.js ` file

For autonomous testing across multiple user personas, check out SUSATest — it explores your app like 10 different real users.

const {lighthouse, prepareAudit} = require (`` @ cypress-audit/lighthouse ''); // const {pa11y} = require (`` @ cypress-audit/pa11y ''); module.exports = {e2e: {baseUrl: `` http: //bstackdemo.com '', // this is your app setupNodeEvents (on, config) {on (`` before: browser: launch '', (browser = {}, launchOptions) = & gt; {prepareAudit (launchOptions);}); on (`` task '', {lighthouse: lighthouse (), // pa11y: pa11y (console.log.bind (console)),});},},};

• Import the Lighthouse commands to the` support/command.js `file in your project:

importee ' @ cypress-audit/lighthouse/commands ';

Step-by-step guide to run your Lighthouse execution tests

This section certify how to run performance exam onbstackdemo.comto see nonremittal execution and SEO metric.

After the initial test, limen are specify to validate the metric against acceptable performance standards.

Part 1: Run Lighthouse performance test without thresholds

Step 1: Add the following codification to your spec file:

describe ('Bstackdemo ', () = & gt; {it ('should run lighthouse performance audits using default thresholds ', () = & gt; {cy.visit ('/ '); cy.lighthouse ();});});

Step 2: In your terminus, run the below command to run your tests in the Chrome browser.

npx cypress open

The next effect is seen:

Part 2: Run Lighthouse performance with limen

Step 1:Add the following code to your spec file:

describe ('Bstackdemo ', () = & gt; {it ('should run lighthouse performance audits employ custom thresholds ', () = & gt; {const door = {performance: 50, accessibility: 80, 'first-contentful-paint ': 2000, 'largest-contentful-paint ': 3000, interactive: 2000, seo: 60, pwa: 50,}; const lighthouseConfig = {formFactor: 'desktop ', screenEmulation: {handicapped: true},}; cy.visit ('/ '); cy.lighthouse (thresholds, lighthouseConfig);});});

In your terminal, run the below command to run your tests in the Chrome browser.

npx cypress unfastened

The following event is seen:

Analyzing Performance Test Results

After scarper both nonpayment and custom threshold performance exam, it becomes clear how metric configurations can impact results. Custom thresholds help effectively maintain performance standards.

• Part 1 runs the application against Google Lighthouse ’ s default execution prosody.
• Part 2 uses custom threshold, which cause performance score to drop importantly.
• These door help enforce minimum performance levels and highlight areas necessitate optimization.

Cypress Performance Testing with BrowserStack

Websites much confront performance challenge under heavy traffic, resulting in slow payload times, clangor, and a poor user experience.

ply teams with a powerful, cloud-based platform to accurately measure, analyze, and optimize website performance with peerless precision and tractableness.

Why Choose BrowserStack for Cypress Performance Testing?

Here ’ s why BrowserStack is the idealistic solution for your load testing needs:

• Simulate Real-World Traffic: Generate thousands of virtual users from various geographics without the demand for complex infrastructure, replicating actual user behavior.
• Unified Insights Across the Stack: View both frontend and backend metric on a single dashboard, allowing you to spot bottlenecks early and troubleshoot issues quickly.
• Seamless CI/CD Integration: Run both browser and API load test directly from your survive test scripts with minimal setup, ensuring performance regression are detected before they hit production.

Load testing is essential to ensure your website can handle real-world traffic without failures. BrowserStack enable you to simulate thousands of virtual users from different fix, helping you name bottlenecks betimes and optimize performance.

With unified reportage that covers both frontend and backend metrics, you can expeditiously troubleshoot issues and ensure your app stay fast and reliable under varying load conditions.

Better Practices for Performance Testing with Cypress

Following a few best practices is important to get authentic and actionable penetration from Cypress execution tests, especially when using Lighthouse alongside Cypress.

1. Run Lighthouse in different geolocations to simulate real user conditions.
2. Define custom performance thresholds sew to your application ’ s need.
3. Schedule Lighthouse tests regularly across a motley of devices and browsers.
4. Integrate performance checks into pipelines for early number spying.

Talk to an Expert

Conclusion

Performance examination is an important lever in examine the constancy of your web application.Through Cypress and Lighthouse though you can analyze execution, you can not ascertain if the experience on multiple devices and operating scheme will remain logical.

To ensure consistent performance, you can rely on. Using, you get access to a. Apart from this, when you use BrowserStack, you can tape your tests, generate reports, and more.

Useful Resources for Cypress

Understanding Cypress

Use Cases

Tool Comparisons

Related Guides