Pull Request Overview

This PR fixes the binding regression for custom 404 pages by changing the configuration property type and updating affected tests, and suppresses a compatibility warning.

• Changed Error404Collection from ISet<ContentErrorPage> to IEnumerable<ContentErrorPage> with a C# 12 collection expression default.
• Updated unit test initializer syntax in ContentSettingsValidatorTests.cs to use [...].
• Added a compatibility suppression for the breaking change in CompatibilitySuppressions.xml.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

public IEnumerable<ContentErrorPage> Error404Collection { get; set; } = [];

///     Gets or sets a value for the collection of error pages.

Looks good to me!

Please note that this is a breaking change due to the change of public signature. It is, however, a strictly necessary change which fixes a regression, and thus I'm accepting it for 16.1 👍

I also went the code route to test this 🤓

Given this code:

using Microsoft.Extensions.Options;
using Umbraco.Cms.Core.Composing;
using Umbraco.Cms.Core.Configuration.Models;

namespace Umbraco.Cms.Web.UI.Custom;

public class TestError404CollectionComponent : IComponent
{
    private readonly ContentSettings _contentSettings;
    private readonly ILogger<TestError404CollectionComponent> _logger;

    public TestError404CollectionComponent(
        IOptions<ContentSettings> contentSettings,
        ILogger<TestError404CollectionComponent> logger)
    {
        _logger = logger;
        _contentSettings = contentSettings.Value;
    }

    public void Initialize()
        => _logger.LogInformation(
            "### Found {numberOf404Configs} 404 page configs ###",
            // the fix is breaking, so this line needs updating after applying the fix
            _contentSettings.Error404Collection.Count);

    public void Terminate()
    {
    }
}

public class TestError404CollectionComposer : ComponentComposer<TestError404CollectionComponent>
{
}

...and this 404 configuration:

"Error404Collection": [
  {
	"Culture": "en-us",
	"ContentKey": "575b9a71-28d2-47b0-bd94-ab98e0fc5f2d"
  },
  {
	"Culture": "da-dk",
	"ContentKey": "d35282e3-3a2d-4566-965a-c2d91b0fe46e"
  }
]

Without the fix I get: ### Found 0 404 page configs ### ❌

With the fix I get the expected: ### Found 2 404 page configs ### ✅