Fix fetch request in data-enhance-nav="false" for same-page anchors

[dariatiurina]

Fix fetch request in data-enhance-nav="false" for same-page anchors

Description

This pull request enhances the navigation logic to better handle hash-only changes in URLs, ensuring that navigation to anchors within the same page does not trigger a full page reload or unnecessary fetch requests. It introduces a utility function to detect hash-only changes and updates the navigation handler to leverage this, improving performance and user experience. Additional end-to-end tests and markup updates verify and demonstrate the new behavior.

Changes:

• Added the isHashOnlyChange utility function in NavigationUtils.ts to detect when a navigation event only changes the hash fragment, avoiding unnecessary page loads.
• Updated the onPopState handler in NavigationEnhancement.ts to use isHashOnlyChange, preventing enhanced navigation logic from running when only the hash changes.
• Added a new end-to-end test in EnhancedNavigationTest.cs to verify that non-enhanced navigation to a hash does not trigger a page fetch, ensuring the scroll behavior works as expected without unnecessary network activity.

Fixes #63396

[Copilot]

Pull Request Overview

This pull request fixes an issue where navigation to same-page anchors (hash-only URL changes) with data-enhance-nav="false" would still trigger unnecessary fetch requests. The fix introduces better detection of hash-only changes to prevent full page reloads and improve performance when navigating to anchors within the same page.

• Added isHashOnlyChange utility function to detect when navigation only changes the URL hash
• Updated onPopState handler to skip enhanced navigation logic for hash-only changes
• Added comprehensive test coverage to verify the fix prevents unnecessary fetch requests

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
NavigationUtils.ts	Added isHashOnlyChange utility function to detect hash-only URL changes
NavigationEnhancement.ts	Updated onPopState handler to use isHashOnlyChange and skip enhanced navigation
PageForScrollingToHash.razor	Added test markup with data-enhance-nav="false" anchor for testing
EnhancedNavigationTest.cs	Added end-to-end test to verify no fetch requests occur for non-enhanced hash navigation

[ilonatommy]

We have the link scenaro covered in the test (<a/> element).
Let's also make sure that other cases work as expected:

• Programmatic navigation (<button @OnClick="@(() => NavigationManager.NavigateTo(ulr#otherHash))">)
• NavLink navigation (<NavLink href="ulr#otherHash">)
• POST navigation, a form that uses custom onsumbit method with redirection to "ulr#otherHash" and disables enhanced nav. A variation on: https://github.com/dotnet/aspnetcore/blob/2cd7fb4901bfe710f2cf0ab23e411d7f7ef5f364/src/Components/test/testassets/TestContentPackage/NotFound/ComponentThatPostsNotFound.razor.

[dariatiurina]

We have the link scenaro covered in the test (<a/> element). Let's also make sure that other cases work as expected:

• Programmatic navigation (<button @OnClick="@(() => NavigationManager.NavigateTo(ulr#otherHash))">)
• NavLink navigation (<NavLink href="ulr#otherHash">)
• POST navigation, a form that uses custom onsumbit method with redirection to "ulr#otherHash" and disables enhanced nav. A variation on: https://github.com/dotnet/aspnetcore/blob/2cd7fb4901bfe710f2cf0ab23e411d7f7ef5f364/src/Components/test/testassets/TestContentPackage/NotFound/ComponentThatPostsNotFound.razor.

NavigateTo behaves differently from <a/> and <NavLink/> with enhanced navigation, so this bug does not affect them.

[ilonatommy]

/backport to release/10.0

[github-actions]

Started backporting to release/10.0: https://github.com/dotnet/aspnetcore/actions/runs/18220339527