Remove diagnostic suppressor

Author: MackinnonBuck

ModelContextProtocol.slnx

@@ -78,6 +78,6 @@
     <Project Path="tests/ModelContextProtocol.Tests/ModelContextProtocol.Tests.csproj" />
     <Project Path="tests/ModelContextProtocol.TestServer/ModelContextProtocol.TestServer.csproj" />
     <Project Path="tests/ModelContextProtocol.TestSseServer/ModelContextProtocol.TestSseServer.csproj" />
-    <Project Path="tests/ModelContextProtocol.SuppressorRegressionTest/ModelContextProtocol.SuppressorRegressionTest.csproj" />
+    <Project Path="tests/ModelContextProtocol.ExperimentalApiRegressionTest/ModelContextProtocol.ExperimentalApiRegressionTest.csproj" />
   </Folder>
 </Solution>

src/ModelContextProtocol.Analyzers/MCPEXP001Suppressor.cs

@@ -1,14 +1,11 @@
 using System.Text.Json.Serialization;
 using ModelContextProtocol.Protocol;
 
-namespace ModelContextProtocol.SuppressorRegressionTest;
+namespace ModelContextProtocol.ExperimentalApiRegressionTest;
 
 /// <summary>
-/// This file validates that the MCPEXP001 diagnostic suppressor works correctly.
-/// By including MCP protocol types that have experimental properties in a
-/// <see cref="JsonSerializerContext"/>, we verify that the source generator does
-/// not produce unsuppressed MCPEXP001 diagnostics. If the suppressor is removed
-/// or broken, this project will fail to build.
+/// This file validates that the System.Text.Json source generator does not produce
+/// MCPEXP001 diagnostics for MCP protocol types with experimental properties.
 /// </summary>
 [JsonSerializable(typeof(Tool))]
 [JsonSerializable(typeof(ServerCapabilities))]

tests/ModelContextProtocol.Analyzers.Tests/MCPEXP001SuppressorTests.cs

@@ -7,11 +7,10 @@
     <IsPackable>false</IsPackable>
 
     <!--
-      This project validates the MCPEXP001 diagnostic suppressor.
+      This project validates that MCPEXP001 diagnostics are NOT emitted by the
+      System.Text.Json source generator for types with experimental properties.
       tests/Directory.Build.props suppresses MCPEXP001 globally for all test projects,
       but this project must NOT suppress it: its successful compilation IS the test.
-      If the suppressor breaks, this project will fail to build with MCPEXP001 errors
-      from the source-generated code that references experimental types.
     -->
     <NoWarn>$(NoWarn.Replace('MCPEXP001',''))</NoWarn>
 
@@ -25,9 +24,6 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\src\ModelContextProtocol.Core\ModelContextProtocol.Core.csproj" />
-    <ProjectReference Include="..\..\src\ModelContextProtocol.Analyzers\ModelContextProtocol.Analyzers.csproj"
-                      OutputItemType="Analyzer"
-                      ReferenceOutputAssembly="false" />
   </ItemGroup>
 
 </Project>

…ExperimentalPropertyRegressionContext.cs …ExperimentalPropertyRegressionContext.cstests/ModelContextProtocol.SuppressorRegressionTest/ExperimentalPropertyRegressionContext.cs renamed to tests/ModelContextProtocol.ExperimentalApiRegressionTest/ExperimentalPropertyRegressionContext.cs tests/ModelContextProtocol.SuppressorRegressionTest/ExperimentalPropertyRegressionContext.cs renamed to tests/ModelContextProtocol.ExperimentalApiRegressionTest/ExperimentalPropertyRegressionContext.cs

@@ -0,0 +1,118 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using ModelContextProtocol.Protocol;
+
+namespace ModelContextProtocol.Tests;
+
+/// <summary>
+/// Validates that the internal property pattern used for experimental properties
+/// produces the expected serialization behavior for SDK consumers using source generators.
+/// </summary>
+/// <remarks>
+/// <para>
+/// Experimental properties (e.g. <see cref="Tool.Execution"/>, <see cref="ServerCapabilities.Tasks"/>)
+/// use an internal <c>*Core</c> property for serialization. A consumer's source-generated
+/// <see cref="JsonSerializerContext"/> cannot see internal members, so experimental data is
+/// silently dropped unless the consumer chains the SDK's resolver into their options.
+/// </para>
+/// <para>
+/// These tests depend on <see cref="Tool.Execution"/> and <see cref="ServerCapabilities.Tasks"/>
+/// being experimental. When those APIs stabilize, update these tests to reference whatever
+/// experimental properties exist at that time, or remove them entirely if no experimental
+/// APIs remain.
+/// </para>
+/// </remarks>
+public class ExperimentalPropertySerializationTests
+{
+    [Fact]
+    public void ExperimentalProperties_Dropped_WithConsumerContextOnly()
+    {
+        var options = new JsonSerializerOptions
+        {
+            TypeInfoResolverChain = { ConsumerJsonContext.Default }
+        };
+
+        var tool = new Tool
+        {
+            Name = "test-tool",
+            Execution = new ToolExecution { TaskSupport = ToolTaskSupport.Optional }
+        };
+
+        string json = JsonSerializer.Serialize(tool, options);
+        Assert.DoesNotContain("\"execution\"", json);
+        Assert.Contains("\"name\"", json);
+    }
+
+    [Fact]
+    public void ExperimentalProperties_IgnoredOnDeserialize_WithConsumerContextOnly()
+    {
+        string json = JsonSerializer.Serialize(
+            new Tool
+            {
+                Name = "test-tool",
+                Execution = new ToolExecution { TaskSupport = ToolTaskSupport.Optional }
+            },
+            McpJsonUtilities.DefaultOptions);
+        Assert.Contains("\"execution\"", json);
+
+        var options = new JsonSerializerOptions
+        {
+            TypeInfoResolverChain = { ConsumerJsonContext.Default }
+        };
+        var deserialized = JsonSerializer.Deserialize<Tool>(json, options)!;
+        Assert.Equal("test-tool", deserialized.Name);
+        Assert.Null(deserialized.Execution);
+    }
+
+    [Fact]
+    public void ExperimentalProperties_RoundTrip_WhenSdkResolverIsChained()
+    {
+        var options = new JsonSerializerOptions
+        {
+            TypeInfoResolverChain =
+            {
+                McpJsonUtilities.DefaultOptions.TypeInfoResolver!,
+                ConsumerJsonContext.Default,
+            }
+        };
+
+        var tool = new Tool
+        {
+            Name = "test-tool",
+            Execution = new ToolExecution { TaskSupport = ToolTaskSupport.Optional }
+        };
+
+        string json = JsonSerializer.Serialize(tool, options);
+        Assert.Contains("\"execution\"", json);
+        Assert.Contains("\"name\"", json);
+
+        var deserialized = JsonSerializer.Deserialize<Tool>(json, options)!;
+        Assert.Equal("test-tool", deserialized.Name);
+        Assert.NotNull(deserialized.Execution);
+        Assert.Equal(ToolTaskSupport.Optional, deserialized.Execution.TaskSupport);
+    }
+
+    [Fact]
+    public void ExperimentalProperties_RoundTrip_WithDefaultOptions()
+    {
+        var capabilities = new ServerCapabilities
+        {
+            Tasks = new McpTasksCapability()
+        };
+
+        string json = JsonSerializer.Serialize(capabilities, McpJsonUtilities.DefaultOptions);
+        Assert.Contains("\"tasks\"", json);
+
+        var deserialized = JsonSerializer.Deserialize<ServerCapabilities>(json, McpJsonUtilities.DefaultOptions)!;
+        Assert.NotNull(deserialized.Tasks);
+    }
+}
+
+[JsonSerializable(typeof(Tool))]
+[JsonSerializable(typeof(ServerCapabilities))]
+[JsonSerializable(typeof(ClientCapabilities))]
+[JsonSerializable(typeof(CallToolResult))]
+[JsonSerializable(typeof(CallToolRequestParams))]
+[JsonSerializable(typeof(CreateMessageRequestParams))]
+[JsonSerializable(typeof(ElicitRequestParams))]
+internal partial class ConsumerJsonContext : JsonSerializerContext;