fixed tests for resource list changes.

Author: Tyler-R-Kendrick

src/ModelContextProtocol/Protocol/Types/ReadResourceRequestParams.cs

@@ -10,5 +10,5 @@ public class ReadResourceRequestParams : RequestParams
     /// The URI of the resource to read. The URI can use any protocol; it is up to the server how to interpret it.
     /// </summary>
     [System.Text.Json.Serialization.JsonPropertyName("uri")]
-    public string? Uri { get; init; }
+    public required string Uri { get; init; }
 }

src/ModelContextProtocol/Server/McpServer.cs

@@ -71,7 +71,7 @@ public McpServer(ITransport transport, McpServerOptions options, ILoggerFactory?
 
         RegisterListChange(capabilities?.Tools, NotificationMethods.ToolListChangedNotification);
         RegisterListChange(capabilities?.Prompts, NotificationMethods.PromptListChangedNotification);
-        RegisterListChange(capabilities?.Resources, RequestMethods.ResourcesList);
+        RegisterListChange(capabilities?.Resources, NotificationMethods.ResourceListChangedNotification);
 
         // And initialize the session.
         InitializeSession(transport);
@@ -185,14 +185,9 @@ private void SetResourcesHandler(McpServerOptions options)
 
         var listResourcesHandler = resourcesCapability.ListResourcesHandler;
         var listResourceTemplatesHandler = resourcesCapability.ListResourceTemplatesHandler;
+        var readResourceHandler = resourcesCapability.ReadResourceHandler;
         var resourceCollection = resourcesCapability.ResourceCollection;
 
-        if ((listResourcesHandler is not { } && listResourceTemplatesHandler is not { }) ||
-            resourcesCapability.ReadResourceHandler is not { } readResourceHandler)
-        {
-            throw new McpException("Resources capability was enabled, but ListResources and/or ReadResource handlers were not specified.");
-        }
-
         var originalListResourcesHandler = listResourcesHandler;
         listResourcesHandler = async (request, cancellationToken) =>
         {
@@ -208,12 +203,19 @@ await originalListResourcesHandler(request, cancellationToken).ConfigureAwait(fa
             return result;
         };
 
+        var isMissingListResourceHandlers = originalListResourcesHandler is not { } && listResourceTemplatesHandler is not { };
+        if (resourceCollection is not { IsEmpty: false } && (isMissingListResourceHandlers || readResourceHandler is not { }))
+        {
+            throw new McpException("Resources capability was enabled, but ListResources, ListResourceTemplates, and/or ReadResource handlers were not specified.");
+        }
+
         RequestHandlers.Set(
             RequestMethods.ResourcesList,
             (request, cancellationToken) => listResourcesHandler(new(this, request), cancellationToken),
             McpJsonUtilities.JsonContext.Default.ListResourcesRequestParams,
             McpJsonUtilities.JsonContext.Default.ListResourcesResult);
 
+        readResourceHandler ??= static (_, _) => Task.FromResult(new ReadResourceResult());
         RequestHandlers.Set(
             RequestMethods.ResourcesRead,
             (request, cancellationToken) => readResourceHandler(new(this, request), cancellationToken),

tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsResourcesTests.cs

@@ -50,8 +50,8 @@ public void Adds_Resources_To_Server()
         var resources = serverOptions?.Capabilities?.Resources?.ResourceCollection;
         Assert.NotNull(resources);
         Assert.Equal(2, resources.Count);
-        Assert.Equal("test.txt", resources["test"].Name);
-        Assert.Equal("test2.txt", resources["test2"].Name);
+        Assert.Equal("test", resources["test"].Name);
+        Assert.Equal("test2", resources["test2"].Name);
     }
 
     [Fact]
@@ -79,7 +79,7 @@ public async Task Can_Be_Notified_Of_ResourceList_Changes()
             .GetRequiredService<IOptions<McpServerOptions>>()
             .Value;
         TaskCompletionSource<JsonRpcNotification> changeReceived = new();
-        client.RegisterNotificationHandler(
+        await using var _ = client.RegisterNotificationHandler(
             NotificationMethods.ResourceListChangedNotification,
             (notification, token) =>
             {