Workaround for ServiceCollection.Configure<T> failing where T is ConcurrentDictionary<string, TMyConfig> in NET7

Description

I have an ModuleCollection class which is:

/// <summary>
/// The set of modules for backend processing.
/// </summary>
public class ModuleCollection : ConcurrentDictionary<string, ModuleConfig>
{
    /// <summary>
    /// This constructor allows our modules collection to be case insensitive on the key.
    /// </summary>
    public ModuleCollection() : base(StringComparer.OrdinalIgnoreCase) { }
}

In NET6:

services.Configure<ModuleCollection>(configuration.GetSection("Modules"));

would load the ModuleCollection with the ModuleConfigs from multiple modulesettings.json files that had been registered with the ConfigurationBuilder. The IOption<ModuleCollection> injected would have the populated collection as its value.

In NET7, the IOption<ModuleCollection>.Value is an empty ModuleCollection.

Workaround

I worked around this by:

services.AddOptions<ModuleCollection>()
        .Configure(moduleCollection =>
        {
            var moduleNames = configuration.GetSection("Modules").GetChildren().Select(x => x.Key).ToList();
            foreach (var moduleName in moduleNames)
            {
                if (moduleName is not null)
                {
                    ModuleConfig moduleConfig = new ModuleConfig();
                    configuration.Bind($"Modules:{moduleName}", moduleConfig);
                    moduleCollection.TryAdd(moduleName, moduleConfig);
                }
            }
        });

Expected Behavior

Same as NET6
IOption<ModuleCollection>.Value contains the collection of ModuleConfigs.

Actual Behavior

The IOption<ModuleCollection>.Value is an empty collection.

Issue Tracking

This issue is being tracked in
ServiceCollection.Configure<ConcurrentDictionary<string, T>>(IConfigurationSection) fails in NET7 · Issue #78994 · dotnet/runtime · GitHub[^],

Configuration

NET7, VS2022 17.4.1

History

• 29^th November, 2022: Initial version