fix: Address PR Comments

dotnet/src/Microsoft.Agents.AI.Workflows/MagenticWorkflowBuilder.cs

@@ -99,9 +99,11 @@ public class MagenticWorkflowBuilder(AIAgent managerAgent)
 
     private WorkflowBuilder ReduceToWorkflowBuilder()
     {
-        ExecutorFactoryFunc factory = this.CreateOrchestratorAsync;
-        ExecutorBinding orchestrator = factory.BindExecutor(nameof(MagenticOrchestrator));
+        // Create a copy of the team so that improper modifications by using the builder after .Build() do not affect the
+        // workflow in unexpected ways.
+        List<AIAgent> team = [.. this._team];
 
+        ExecutorBinding orchestrator = CreateOrchestratorBinding(managerAgent, team, this.Limits, this._requirePlanSignoff);
         WorkflowBuilder result = new(orchestrator);
 
         AIAgentHostOptions options = new()
@@ -111,7 +113,7 @@ public class MagenticWorkflowBuilder(AIAgent managerAgent)
         };
 
         List<ExecutorBinding> teamBindings = [];
-        foreach (AIAgent agent in this._team)
+        foreach (AIAgent agent in team)
         {
             ExecutorBinding binding = agent.BindAsExecutor(options);
             teamBindings.Add(binding);
@@ -143,8 +145,14 @@ public class MagenticWorkflowBuilder(AIAgent managerAgent)
         MaxResetCount: this._maxResets,
         MaxStallCount: this._maxStalls);
 
-    private ValueTask<MagenticOrchestrator> CreateOrchestratorAsync(ExecutorConfig<ExecutorOptions> options, string sessionId)
+    private static ExecutorBinding CreateOrchestratorBinding(AIAgent managerAgent, List<AIAgent> team, TaskLimits limits, bool requirePlanSignoff)
     {
-        return new(new MagenticOrchestrator(managerAgent, this._team, this.Limits, this._requirePlanSignoff));
+        ExecutorFactoryFunc factory = CreateOrchestratorAsync;
+        return factory.BindExecutor(nameof(MagenticOrchestrator));
+
+        ValueTask<MagenticOrchestrator> CreateOrchestratorAsync(ExecutorConfig<ExecutorOptions> options, string sessionId)
+        {
+            return new(new MagenticOrchestrator(managerAgent, team, limits, requirePlanSignoff));
+        }
     }
 }

dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/Magentic/ChatMessageExtensions.cs

@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Text;
 using System.Text.Json;
@@ -112,9 +113,8 @@ internal static partial class ChatMessageExtensions
         new(FencedJsonRegexPattern, RegexOptions.Compiled | RegexOptions.CultureInvariant | RegexOptions.ExplicitCapture);
 #endif
 
-    public static JsonElement ExtractJson(this ChatMessage message)
+    internal static JsonElement ExtractJson(string messageText)
     {
-        string messageText = message.Text;
         Match match = FencedJsonRegex().Match(messageText);
         if (match.Success)
         {
@@ -130,20 +130,35 @@ internal static partial class ChatMessageExtensions
         }
 
         int depth = 0;
+        bool inQuotes = false, inEscape = false;
         for (; scanHead < messageText.Length && end is null; scanHead++)
         {
+            if (inEscape)
+            {
+                inEscape = false;
+                continue;
+            }
+
             switch (messageText[scanHead])
             {
-                case '{':
+                case '{' when !inQuotes:
                     depth++;
                     break;
-                case '}':
+                case '}' when !inQuotes:
                     depth--;
                     if (depth == 0)
                     {
                         end = scanHead;
                     }
 
+                    break;
+                case '\"':
+                    // We already handled inEscape, so we can always flip inQuotes here
+                    inQuotes = !inQuotes;
+                    break;
+                case '\\':
+                    Debug.Assert(!inEscape);
+                    inEscape = true;
                     break;
             }
         }
@@ -155,4 +170,6 @@ internal static partial class ChatMessageExtensions
 
         return JsonElement.Parse(messageText.Substring(start, end.Value - start + 1));
     }
+
+    public static JsonElement ExtractJson(this ChatMessage message) => ExtractJson(message.Text);
 }

dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowsJsonUtilities.cs

@@ -101,6 +101,7 @@ internal static partial class WorkflowsJsonUtilities
     [JsonSerializable(typeof(MagenticPlanReviewRequest))]
     [JsonSerializable(typeof(MagenticPlanReviewResponse))]
     [JsonSerializable(typeof(MagenticTaskState))]
+    [JsonSerializable(typeof(ResetChatSignal))]
 
     // Event Types
     //[JsonSerializable(typeof(WorkflowEvent))]

dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/MagenticProgressLedgerTests.cs

@@ -11,6 +11,7 @@ namespace Microsoft.Agents.AI.Workflows.UnitTests;
 public class MagenticProgressLedgerTests
 {
     public record KVPair(string key);
+    public record AnswerReasonPair(bool answer, string reason);
 
     [Theory]
     [InlineData(false)]
@@ -92,6 +93,26 @@ public class MagenticProgressLedgerTests
         action.Should().Throw();
     }
 
+    [Fact]
+    public void Test_ExtractJson_SuceedsWithQuotesBrackets()
+    {
+        // Arrange
+        ChatMessage message = new(ChatRole.Assistant,
+"""
+    {"reason":"the output contained }", "answer": false}
+""");
+
+        // Act
+        JsonElement element = message.ExtractJson();
+
+        // Assert
+        AnswerReasonPair? result = element.Deserialize<AnswerReasonPair>();
+
+        result.Should().NotBeNull();
+        result.reason.Should().Be("the output contained }");
+        result.answer.Should().BeFalse();
+    }
+
     public static readonly string TestTeamNames = string.Join(", ", ["CodingAgent", "CodeExecutor", "WebSurferAgent", "FileSurferAgent"]);
 
     [Fact]