WIP: fix: WorkflowAsAgent Sample

* Also makes ChatForwardingExecutor public

MERGE PENDING #1781

Author: lokitoth

dotnet/samples/GettingStarted/Workflows/Agents/WorkflowAsAnAgent/WorkflowFactory.cs

@@ -16,7 +16,7 @@ internal static class WorkflowFactory
     internal static Workflow BuildWorkflow(IChatClient chatClient)
     {
         // Create executors
-        var startExecutor = new ConcurrentStartExecutor();
+        var startExecutor = new ChatForwardingExecutor("Start");
         var aggregationExecutor = new ConcurrentAggregationExecutor();
         AIAgent frenchAgent = GetLanguageAgent("French", chatClient);
         AIAgent englishAgent = GetLanguageAgent("English", chatClient);
@@ -38,34 +38,11 @@ internal static Workflow BuildWorkflow(IChatClient chatClient)
     private static ChatClientAgent GetLanguageAgent(string targetLanguage, IChatClient chatClient) =>
         new(chatClient, instructions: $"You're a helpful assistant who always responds in {targetLanguage}.", name: $"{targetLanguage}Agent");
 
-    /// <summary>
-    /// Executor that starts the concurrent processing by sending messages to the agents.
-    /// </summary>
-    private sealed class ConcurrentStartExecutor() :
-        Executor<List<ChatMessage>>("ConcurrentStartExecutor")
-    {
-        /// <summary>
-        /// Starts the concurrent processing by sending messages to the agents.
-        /// </summary>
-        /// <param name="message">The user message to process</param>
-        /// <param name="context">Workflow context for accessing workflow services and adding events</param>
-        /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests.
-        /// The default is <see cref="CancellationToken.None"/>.</param>
-        public override async ValueTask HandleAsync(List<ChatMessage> message, IWorkflowContext context, CancellationToken cancellationToken = default)
-        {
-            // Broadcast the message to all connected agents. Receiving agents will queue
-            // the message but will not start processing until they receive a turn token.
-            await context.SendMessageAsync(message, cancellationToken: cancellationToken);
-            // Broadcast the turn token to kick off the agents.
-            await context.SendMessageAsync(new TurnToken(emitEvents: true), cancellationToken: cancellationToken);
-        }
-    }
-
     /// <summary>
     /// Executor that aggregates the results from the concurrent agents.
     /// </summary>
     private sealed class ConcurrentAggregationExecutor() :
-        Executor<ChatMessage>("ConcurrentAggregationExecutor")
+        Executor<ChatMessage>("ConcurrentAggregationExecutor"), IResettableExecutor
     {
         private readonly List<ChatMessage> _messages = [];
 
@@ -86,5 +63,12 @@ public override async ValueTask HandleAsync(ChatMessage message, IWorkflowContex
                 await context.YieldOutputAsync(formattedMessages, cancellationToken);
             }
         }
+
+        /// <inheritdoc/>
+        public ValueTask ResetAsync()
+        {
+            this._messages.Clear();
+            return default;
+        }
     }
 }

dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/ChatForwardingExecutor.cs renamed to dotnet/src/Microsoft.Agents.AI.Workflows/ChatForwardingExecutor.cs

@@ -4,17 +4,26 @@
 using System.Threading.Tasks;
 using Microsoft.Extensions.AI;
 
-namespace Microsoft.Agents.AI.Workflows.Specialized;
+namespace Microsoft.Agents.AI.Workflows;
 
-/// <summary>Executor that forwards all messages.</summary>
-internal sealed class ChatForwardingExecutor(string id) : Executor(id, declareCrossRunShareable: true), IResettableExecutor
+/// <summary>
+/// A ChatProtocol executor that forwards all messages it receives. Useful for splitting inputs into parallel
+/// processing paths.
+/// </summary>
+/// <remarks>This executor is designed to be cross-run shareable and can be reset to its initial state. It handles
+/// multiple chat-related types, enabling flexible message forwarding scenarios. Thread safety and reusability are
+/// ensured by its design.</remarks>
+/// <param name="id">The unique identifier for the executor instance. Used to distinguish this executor within the system.</param>
+public sealed class ChatForwardingExecutor(string id) : Executor(id, declareCrossRunShareable: true), IResettableExecutor
 {
-    protected override RouteBuilder ConfigureRoutes(RouteBuilder routeBuilder) =>
+    /// <inheritdoc/>
+    protected sealed override RouteBuilder ConfigureRoutes(RouteBuilder routeBuilder) =>
         routeBuilder
                 .AddHandler<string>((message, context, cancellationToken) => context.SendMessageAsync(new ChatMessage(ChatRole.User, message), cancellationToken: cancellationToken))
                 .AddHandler<ChatMessage>((message, context, cancellationToken) => context.SendMessageAsync(message, cancellationToken: cancellationToken))
                 .AddHandler<List<ChatMessage>>((messages, context, cancellationToken) => context.SendMessageAsync(messages, cancellationToken: cancellationToken))
                 .AddHandler<TurnToken>((turnToken, context, cancellationToken) => context.SendMessageAsync(turnToken, cancellationToken: cancellationToken));
 
+    /// <inheritdoc/>
     public ValueTask ResetAsync() => default;
 }