Testing Large Data Grids with Playwright

Modern web applications often include complex UI components like data grids, especially in enterprise and data-centric environments. These grids may contain hundreds or thousands of rows and columns, supporting features like filtering, sorting, pagination, and lazy loading. Ensuring they function correctly across all scenarios is critical — and that’s where Playwright, a powerful end-to-end testing tool from Microsoft, shines.

In this blog, we’ll explore how to test large data grids using Playwright, covering key strategies, performance considerations, and real-world examples to help you build reliable test automation.

Why Choose Playwright for Data Grid Testing?

Playwright is an open-source Node.js library designed for browser automation. It supports multiple browsers (Chromium, Firefox, and WebKit), parallel testing, and features like auto-waiting and browser context isolation, making it ideal for testing complex web components.

Here’s why Playwright is great for large data grid testing:

• Handles dynamic content and lazy loading
• Supports robust selectors and smart waits
• Allows interaction with shadow DOM and iframes
• Can simulate user actions accurately (e.g., scrolling, typing, clicking)

Common Challenges in Data Grid Testing

Before jumping into the code, let’s identify some challenges associated with testing large data grids:

• Dynamic Loading: Rows may load on scroll or button clicks (pagination).
• Data Volume: High number of records can affect load time and performance.
• Interactivity: Grids often support sorting, filtering, inline editing, and multi-select.
• Complex Selectors: Identifying cells based on row and column positions can be tricky.

Playwright provides flexible APIs to address these challenges.

Setting Up Playwright

To get started, install Playwright:

bash

npm init playwright@latest

This command installs Playwright and sets up the basic configuration. You can choose your preferred language (JavaScript/TypeScript) and browser(s).

Sample Test: Validating Rows in a Large Data Grid

Assume your data grid is paginated and supports sorting. Here's a simplified test example using JavaScript:

javascript

const { test, expect } = require('@playwright/test');

test('Validate data grid pagination and sorting', async ({ page }) => {

  await page.goto('https://example.com/data-grid');

  // Wait for the grid to load

  await page.waitForSelector('.data-grid');

  // Validate the first row on page 1

  const firstRowCell = await page.locator('.data-grid-row').first().locator('td').nth(1);

  await expect(firstRowCell).toHaveText('Item 1');

  // Click on the next page

  await page.click('button[aria-label="Next Page"]');

  await page.waitForTimeout(1000); // Adjust based on load time

  // Validate a value on page 2

  const secondPageFirstRow = await page.locator('.data-grid-row').first().locator('td').nth(1);

  await expect(secondPageFirstRow).toHaveText('Item 21');

  // Sort by a column

  await page.click('th[data-column="price"]');

  const sortedFirstRow = await page.locator('.data-grid-row').first().locator('td').nth(2);

  await expect(sortedFirstRow).toContainText('$');

});

Tips for Testing Large Grids

1. Use Pagination Over Scrolling: Scrolling-based tests can be flaky; prefer grids with clear page navigation.
2. Wait Strategically: Use Playwright’s locator.waitFor() or expect().toHaveText() instead of hard-coded timeouts.
3. Test Edge Cases: Validate the first, middle, and last rows of large datasets.
4. Mock Large Data Sets: When possible, mock API responses using Playwright’s network mocking features to simulate high volume data.
5. Accessibility & Responsiveness: Ensure grid components are accessible and render properly across devices.

Conclusion

Testing large data grids is essential to ensure data integrity, performance, and user experience. With Playwright, testers gain a reliable and scalable framework to automate complex UI interactions, verify dynamic behaviors, and streamline regression testing. Whether you're working with paginated data, lazy-loaded rows, or advanced filtering, Playwright offers the tools and flexibility to handle it all — and with high confidence.

By mastering these techniques, you can build robust tests that keep your grid-based applications performant and error-free.

Learn Playwright Testing Training
Read More: Automating CMS Interfaces Using Playwright

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