Ensure ComponentState is always disposed

src/Components/Components/src/PublicAPI.Unshipped.txt

@@ -19,6 +19,7 @@ Microsoft.AspNetCore.Components.ParameterView.ToDictionary() -> System.Collectio
 Microsoft.AspNetCore.Components.RenderHandle.DispatchExceptionAsync(System.Exception! exception) -> System.Threading.Tasks.Task!
 *REMOVED*Microsoft.AspNetCore.Components.NavigationManager.ToAbsoluteUri(string! relativeUri) -> System.Uri!
 Microsoft.AspNetCore.Components.NavigationManager.ToAbsoluteUri(string? relativeUri) -> System.Uri!
+Microsoft.AspNetCore.Components.Rendering.ComponentState.DisposeAsync() -> System.Threading.Tasks.ValueTask
 Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder.SetEventHandlerName(string! eventHandlerName) -> void
 *REMOVED*Microsoft.AspNetCore.Components.RouteData.RouteData(System.Type! pageType, System.Collections.Generic.IReadOnlyDictionary<string!, object!>! routeValues) -> void
 *REMOVED*Microsoft.AspNetCore.Components.RouteData.RouteValues.get -> System.Collections.Generic.IReadOnlyDictionary<string!, object!>!
@@ -34,7 +35,6 @@ Microsoft.AspNetCore.Components.Rendering.ComponentState
 Microsoft.AspNetCore.Components.Rendering.ComponentState.Component.get -> Microsoft.AspNetCore.Components.IComponent!
 Microsoft.AspNetCore.Components.Rendering.ComponentState.ComponentId.get -> int
 Microsoft.AspNetCore.Components.Rendering.ComponentState.ComponentState(Microsoft.AspNetCore.Components.RenderTree.Renderer! renderer, int componentId, Microsoft.AspNetCore.Components.IComponent! component, Microsoft.AspNetCore.Components.Rendering.ComponentState? parentComponentState) -> void
-Microsoft.AspNetCore.Components.Rendering.ComponentState.Dispose() -> void
 Microsoft.AspNetCore.Components.Rendering.ComponentState.ParentComponentState.get -> Microsoft.AspNetCore.Components.Rendering.ComponentState?
 Microsoft.AspNetCore.Components.RenderTree.Renderer.GetComponentState(int componentId) -> Microsoft.AspNetCore.Components.Rendering.ComponentState!
 Microsoft.AspNetCore.Components.Sections.SectionContent

src/Components/Components/src/RenderTree/Renderer.cs

@@ -1080,39 +1080,25 @@ protected virtual void Dispose(bool disposing)
         {
             Log.DisposingComponent(_logger, componentState);
 
-            // Components shouldn't need to implement IAsyncDisposable and IDisposable simultaneously,
-            // but in case they do, we prefer the async overload since we understand the sync overload
-            // is implemented for more "constrained" scenarios.
-            // Component authors are responsible for their IAsyncDisposable implementations not taking
-            // forever.
-            if (componentState.Component is IAsyncDisposable asyncDisposable)
+            try
             {
-                try
+                var task = componentState.DisposeAsync();
+                if (task.IsCompletedSuccessfully)
                 {
-                    var task = asyncDisposable.DisposeAsync();
-                    if (!task.IsCompletedSuccessfully)
-                    {
-                        asyncDisposables ??= new();
-                        asyncDisposables.Add(task.AsTask());
-                    }
+                    // If it's a IValueTaskSource backed ValueTask,
+                    // inform it its result has been read so it can reset
+                    task.GetAwaiter().GetResult();
                 }
-                catch (Exception exception)
+                else
                 {
-                    exceptions ??= new List<Exception>();
-                    exceptions.Add(exception);
+                    asyncDisposables ??= new();
+                    asyncDisposables.Add(task.AsTask());
                 }
             }
-            else if (componentState.Component is IDisposable disposable)
+            catch (Exception exception)
             {
-                try
-                {
-                    componentState.Dispose();
-                }
-                catch (Exception exception)
-                {
-                    exceptions ??= new List<Exception>();
-                    exceptions.Add(exception);
-                }
+                exceptions ??= new List<Exception>();
+                exceptions.Add(exception);
             }
         }
 

src/Components/Components/src/Rendering/ComponentState.cs

@@ -13,7 +13,7 @@ namespace Microsoft.AspNetCore.Components.Rendering;
 /// detail of <see cref="Renderer"/>.
 /// </summary>
 [DebuggerDisplay($"{{{nameof(GetDebuggerDisplay)}(),nq}}")]
-public class ComponentState : IDisposable
+public class ComponentState : IAsyncDisposable
 {
     private readonly Renderer _renderer;
     private readonly IReadOnlyList<CascadingParameterState> _cascadingParameters;
@@ -254,15 +254,25 @@ private void RemoveCascadingParameterSubscriptions()
     }
 
     /// <summary>
-    /// Disposes this instance.
+    /// Disposes this instance and its associated component.
     /// </summary>
-    public void Dispose()
+    public ValueTask DisposeAsync()
     {
         DisposeBuffers();
 
-        if (Component is IDisposable disposable)
+        // Components shouldn't need to implement IAsyncDisposable and IDisposable simultaneously,
+        // but in case they do, we prefer the async overload since we understand the sync overload
+        // is implemented for more "constrained" scenarios.
+        // Component authors are responsible for their IAsyncDisposable implementations not taking
+        // forever.
+        if (Component is IAsyncDisposable asyncDisposable)
         {
-            disposable.Dispose();
+            return asyncDisposable.DisposeAsync();
+        }
+        else
+        {
+            (Component as IDisposable)?.Dispose();
+            return ValueTask.CompletedTask;
         }
     }