Validating Header and Footer Persistence After a Click

Overview

When testing web applications, it's important to verify that certain actions, like clicking a link, do not cause an unintended full-page reload. A common indicator of a full-page reload is the re-rendering of static elements like the header and footer. This document outlines a method using custom JavaScript to validate that the header and footer elements persist and are not reloaded after a user action.

How It Works

The validation is performed using two separate custom code steps to check if the Document Object Model (DOM) elements for the header and footer have been re-rendered.

Step 1: Store Initial Element References

Before the action (e.g., a click) is performed, use a custom code step to capture the DOM nodes for the header and footer. These references are stored in global window variables to be accessed by the next step.

Code:

javascript
// Replace '.your-header-selector' and '.your-footer-selector' with the actual CSS selectors.
window.headerRef = document.querySelector('.your-header-selector');
window.footerRef = document.querySelector('.your-footer-selector');

Step 2: Compare Element References

After the action has been performed, use a second custom code step to retrieve the current header and footer elements. This step then performs a strict comparison (===) between the current element references and the ones stored previously. The step returns true if the elements are the same and false if they have been re-rendered.

Code:

javascript
// Replace with the same selectors used in the first step.
const currentHeader = document.querySelector('.your-header-selector');
const currentFooter = document.querySelector('.your-footer-selector');

// Returns true if the references are the same, indicating no reload.
return (
    currentHeader === window.headerRef &&
    currentFooter === window.footerRef
);

This method is effective because the strict equality check (===) compares the elements' references in memory. If an element is re-rendered, a new DOM object with a new reference is created, causing the comparison to fail. This reliably detects if the header or footer was refreshed at any point after the initial click.

Limitations

Stable Selectors: This approach relies on stable and unique CSS selectors for the header and footer. If the application's code changes, these selectors may need to be updated.
Scope: This validation checks if the container elements for the header and footer are replaced. It does not detect dynamic changes to the content within those elements if the containers themselves are not re-rendered.

Related Info

Single-Page Applications (SPAs): This technique is particularly useful for testing SPAs, where client-side navigation should not trigger full-page reloads.
DOM APIs: The method uses standard browser JavaScript and DOM APIs, including document.querySelector and the strict equality operator (===).

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