Add client completion notification and details (#1368)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tests/ModelContextProtocol.Tests/Client/ClientCompletionDetailsTests.cs

@@ -0,0 +1,95 @@
+using ModelContextProtocol.Client;
+
+namespace ModelContextProtocol.Tests.Client;
+
+public class ClientCompletionDetailsTests
+{
+    [Fact]
+    public void ClientCompletionDetails_PropertiesRoundtrip()
+    {
+        var exception = new InvalidOperationException("test");
+        var details = new ClientCompletionDetails
+        {
+            Exception = exception,
+        };
+
+        Assert.Same(exception, details.Exception);
+    }
+
+    [Fact]
+    public void ClientCompletionDetails_DefaultsToNull()
+    {
+        var details = new ClientCompletionDetails();
+        Assert.Null(details.Exception);
+    }
+
+    [Fact]
+    public void StdioClientCompletionDetails_PropertiesRoundtrip()
+    {
+        var exception = new IOException("process exited");
+        string[] stderrLines = ["error line 1", "error line 2"];
+
+        var details = new StdioClientCompletionDetails
+        {
+            Exception = exception,
+            ProcessId = 12345,
+            ExitCode = 42,
+            StandardErrorTail = stderrLines,
+        };
+
+        Assert.Same(exception, details.Exception);
+        Assert.Equal(12345, details.ProcessId);
+        Assert.Equal(42, details.ExitCode);
+        Assert.Same(stderrLines, details.StandardErrorTail);
+    }
+
+    [Fact]
+    public void StdioClientCompletionDetails_DefaultsToNull()
+    {
+        var details = new StdioClientCompletionDetails();
+        Assert.Null(details.Exception);
+        Assert.Null(details.ProcessId);
+        Assert.Null(details.ExitCode);
+        Assert.Null(details.StandardErrorTail);
+    }
+
+    [Fact]
+    public void StdioClientCompletionDetails_IsClientCompletionDetails()
+    {
+        ClientCompletionDetails details = new StdioClientCompletionDetails { ExitCode = 1 };
+        var stdio = Assert.IsType<StdioClientCompletionDetails>(details);
+        Assert.Equal(1, stdio.ExitCode);
+    }
+
+    [Fact]
+    public void HttpClientCompletionDetails_PropertiesRoundtrip()
+    {
+        var exception = new HttpRequestException("connection refused");
+
+        var details = new HttpClientCompletionDetails
+        {
+            Exception = exception,
+            HttpStatusCode = System.Net.HttpStatusCode.NotFound,
+        };
+
+        Assert.Same(exception, details.Exception);
+        Assert.Equal(System.Net.HttpStatusCode.NotFound, details.HttpStatusCode);
+    }
+
+    [Fact]
+    public void HttpClientCompletionDetails_DefaultsToNull()
+    {
+        var details = new HttpClientCompletionDetails();
+        Assert.Null(details.Exception);
+        Assert.Null(details.HttpStatusCode);
+    }
+
+    [Fact]
+    public void HttpClientCompletionDetails_IsClientCompletionDetails()
+    {
+        ClientCompletionDetails details = new HttpClientCompletionDetails { HttpStatusCode = System.Net.HttpStatusCode.NotFound };
+        var http = Assert.IsType<HttpClientCompletionDetails>(details);
+        Assert.Equal(System.Net.HttpStatusCode.NotFound, http.HttpStatusCode);
+    }
+
+}