Implement IOptionsFormatter on McpOptions for improved serviceability

src/Microsoft.Azure.Functions.Extensions.Mcp/Configuration/McpOptions.cs

@@ -1,12 +1,16 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+using Microsoft.Azure.WebJobs.Hosting;
+using Newtonsoft.Json.Linq;
+using System.ComponentModel;
+
 namespace Microsoft.Azure.Functions.Extensions.Mcp.Configuration;
 
 /// <summary>
 /// Options for configuring the Model Context Protocol (MCP) extension in Azure Functions.
 /// </summary>
-public sealed class McpOptions
+public sealed class McpOptions : IOptionsFormatter
 {
     private MessageOptions _messageOptions = new();
 
@@ -41,4 +45,20 @@ public MessageOptions MessageOptions
         set => _messageOptions = value
                                  ?? throw new ArgumentNullException(nameof(value),"Message options cannot be null.");
     }
+
+    /// <inheritdoc/>
+    [EditorBrowsable(EditorBrowsableState.Never)]
+    string IOptionsFormatter.Format()
+    {
+        JObject options = new JObject
+            {
+                { nameof(ServerName), ServerName },
+                { nameof(ServerVersion), ServerVersion },
+                { nameof(Instructions), Instructions },
+                { nameof(EncryptClientState), EncryptClientState },
+                { nameof(MessageOptions) + "." + nameof(MessageOptions.UseAbsoluteUriForEndpoint), MessageOptions.UseAbsoluteUriForEndpoint }
+            };
+
+        return options.ToString(Newtonsoft.Json.Formatting.Indented);
+    }
 }

test/Extensions.Mcp.Tests/McpOptionsTests.cs

@@ -2,6 +2,8 @@
 // Licensed under the MIT License.
 
 using Microsoft.Azure.Functions.Extensions.Mcp.Configuration;
+using Microsoft.Azure.WebJobs.Hosting;
+using Newtonsoft.Json.Linq;
 using Xunit;
 
 namespace Microsoft.Azure.Functions.Extensions.Mcp.Tests;
@@ -20,4 +22,45 @@ public void DefaultValues_AreSetCorrectly()
         Assert.NotNull(options.MessageOptions);
         Assert.False(options.MessageOptions.UseAbsoluteUriForEndpoint);
     }
+
+    [Fact]
+    public void Format_ReturnsExpectedJson()
+    {
+        var options = new McpOptions
+        {
+            ServerName = "Test Server",
+            ServerVersion = "2.0.0",
+            Instructions = "Test instructions",
+            EncryptClientState = false
+        };
+        options.MessageOptions.UseAbsoluteUriForEndpoint = true;
+
+        var formatter = (IOptionsFormatter)options;
+        var formatted = formatter.Format();
+
+        Assert.NotNull(formatted);
+
+        var json = JObject.Parse(formatted);
+        Assert.Equal("Test Server", json[nameof(options.ServerName)]?.ToString());
+        Assert.Equal("2.0.0", json[nameof(options.ServerVersion)]?.ToString());
+        Assert.Equal("Test instructions", json[nameof(options.Instructions)]?.ToString());
+        Assert.Equal("False", json[nameof(options.EncryptClientState)]?.ToString());
+        Assert.Equal("True", json["MessageOptions.UseAbsoluteUriForEndpoint"]?.ToString());
+    }
+
+    [Fact]
+    public void Format_IncludesAllNonSensitiveProperties()
+    {
+        var options = new McpOptions();
+        var formatter = (IOptionsFormatter)options;
+        var formatted = formatter.Format();
+
+        var json = JObject.Parse(formatted);
+
+        Assert.Contains(nameof(options.ServerName), json.Properties().Select(p => p.Name));
+        Assert.Contains(nameof(options.ServerVersion), json.Properties().Select(p => p.Name));
+        Assert.Contains(nameof(options.Instructions), json.Properties().Select(p => p.Name));
+        Assert.Contains(nameof(options.EncryptClientState), json.Properties().Select(p => p.Name));
+        Assert.Contains("MessageOptions.UseAbsoluteUriForEndpoint", json.Properties().Select(p => p.Name));
+    }
 }