Cache: Invalidate element GUID-keyed cache on delete (closes #22911)

[AndyButland]

Description

After moving an element to the recycle bin and emptying it, IElementService.GetById(Guid key) still returned the element until the site was restarted.

The EntityByGuidReadRepository used by element/content/media repositories stores its entries with the uRepoGuid_ prefix (via RepositoryCacheKeys.GetGuidKey<T>). ContentCacheRefresher and MediaCacheRefresher were updated to use that prefix when the GUID-keyed cache policy was introduced; ElementCacheRefresher was missed and still cleared with the old uRepo_ prefix (via RepositoryCacheKeys.GetKey<T, TId>), so the GUID-keyed entry was never invalidated.

The fix changes the GUID-key clearing in ElementCacheRefresher.Refresh from GetKey<IElement, Guid?> to GetGuidKey<IElement>, matching the pattern already used for documents and media.

Fixes #22911

Testing

Automated

I wasn't successful getting an integration test running that reliably shows the error before the fix and the resolution afterward.

Manual

Add this temporary debug controller (not committed) and run the site:

using Microsoft.AspNetCore.Mvc;
using Umbraco.Cms.Core.Models;
using Umbraco.Cms.Core.Services;

namespace Umbraco.Cms.Web.UI.Controllers;

public class DebugElementLookupController : Controller
{
    private readonly IElementService _elementService;

    public DebugElementLookupController(IElementService elementService) => _elementService = elementService;

    [HttpGet(\"/debug/element-lookup\")]
    public IActionResult Lookup([FromQuery] Guid key)
    {
        IElement? element = _elementService.GetById(key);
        return element is null
            ? Content(\$\"No element found for key '{key}'.\", \"text/plain\")
            : Content(\$\"Found element '{element.Name}' (id={element.Id}, trashed={element.Trashed}) for key '{key}'.\", \"text/plain\");
    }
}

Reproduction:

1. In the backoffice, create a new element in the Library section and note its key.
2. Move the element to the recycle bin.
3. Empty the recycle bin.
4. Browse to `/debug/element-lookup?key={key}`.

Expected response before the fix:

Found element 'My Element' (id=1234, trashed=True) for key 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee'.

Expected response after the fix:

No element found for key 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee'.

[claude]

Claude finished @AndyButland's task in 2m 28s —— View job

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PR Review

Target: origin/release/18.0 · Based on commit: e2657358
· Skipped: 1 files out of 2 total (the element-publishing.workspace-context.ts change is from a separate commit already in release/18.0 and is not part of this PR)

Corrects the isolated cache invalidation key used when clearing a GUID-keyed element cache entry on delete. The old call used GetKey<IElement, Guid?> (prefix uRepo_IElement_), which never matched the actual stored key; the fix switches to GetGuidKey<IElement> (prefix uRepoGuid_IElement_), matching the key written by EntityByGuidReadRepository and aligning with the identical pattern already in ContentCacheRefresher and MediaCacheRefresher.

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Suggestions

• src/Umbraco.Core/Cache/Refreshers/Implement/ElementCacheRefresher.cs:131: No test specifically asserts that calling Refresh with TreeChangeTypes.Remove evicts the GUID-keyed isolated cache entry. The existing DistributedCacheRefresherTests only covers the elements memory cache, not the IsolatedCaches path. A unit test that verifies IAppPolicyCache.Clear is called with the uRepoGuid_IElement_ key on removal would prevent regression for this exact class of bug.

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Approved

This looks good to be merged as-is. The two-line change is correct, precisely targeted, and directly mirrors the established pattern from ContentCacheRefresher (line 257) and MediaCacheRefresher (line 160). The added comment is justified — the uRepoGuid_ vs uRepo_ prefix distinction is genuinely non-obvious and was the root cause of the original bug.

[Copilot]

Pull request overview

Fixes stale element lookups by GUID after an element is deleted by ensuring the GUID-keyed repository cache entry is invalidated by ElementCacheRefresher, aligning element cache invalidation with the existing content/media pattern.

Changes:

• Update ElementCacheRefresher.Refresh to clear GUID-keyed repository cache entries using RepositoryCacheKeys.GetGuidKey<IElement>(...) (the uRepoGuid_ prefix) instead of the int-key prefix helper.