test: MCP server tests, benchmarks, and nix build fix

- Add MCP server protocol tests (initialize, tools/list, errors)
- Add database benchmarks (batch inserts, search, children)
- Add sample options.json test fixture
- Fix flake.nix vendor hash for nix build

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/mcp/server_test.go

@@ -0,0 +1,190 @@
+package mcp
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"strings"
+	"testing"
+
+	"git.t-juice.club/torjus/labmcp/internal/database"
+)
+
+func TestServerInitialize(t *testing.T) {
+	store := setupTestStore(t)
+	server := NewServer(store, nil)
+
+	input := `{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"test","version":"1.0"}}}`
+
+	resp := runRequest(t, server, input)
+
+	if resp.Error != nil {
+		t.Fatalf("Unexpected error: %v", resp.Error)
+	}
+
+	result, ok := resp.Result.(map[string]interface{})
+	if !ok {
+		t.Fatalf("Expected map result, got %T", resp.Result)
+	}
+
+	if result["protocolVersion"] != ProtocolVersion {
+		t.Errorf("protocolVersion = %v, want %v", result["protocolVersion"], ProtocolVersion)
+	}
+
+	serverInfo := result["serverInfo"].(map[string]interface{})
+	if serverInfo["name"] != "nixos-options" {
+		t.Errorf("serverInfo.name = %v, want nixos-options", serverInfo["name"])
+	}
+}
+
+func TestServerToolsList(t *testing.T) {
+	store := setupTestStore(t)
+	server := NewServer(store, nil)
+
+	input := `{"jsonrpc":"2.0","id":1,"method":"tools/list"}`
+
+	resp := runRequest(t, server, input)
+
+	if resp.Error != nil {
+		t.Fatalf("Unexpected error: %v", resp.Error)
+	}
+
+	result, ok := resp.Result.(map[string]interface{})
+	if !ok {
+		t.Fatalf("Expected map result, got %T", resp.Result)
+	}
+
+	tools, ok := result["tools"].([]interface{})
+	if !ok {
+		t.Fatalf("Expected tools array, got %T", result["tools"])
+	}
+
+	// Should have 6 tools
+	if len(tools) != 6 {
+		t.Errorf("Expected 6 tools, got %d", len(tools))
+	}
+
+	// Check tool names
+	expectedTools := map[string]bool{
+		"search_options":  false,
+		"get_option":      false,
+		"get_file":        false,
+		"index_revision":  false,
+		"list_revisions":  false,
+		"delete_revision": false,
+	}
+
+	for _, tool := range tools {
+		toolMap := tool.(map[string]interface{})
+		name := toolMap["name"].(string)
+		if _, ok := expectedTools[name]; ok {
+			expectedTools[name] = true
+		}
+	}
+
+	for name, found := range expectedTools {
+		if !found {
+			t.Errorf("Tool %q not found in tools list", name)
+		}
+	}
+}
+
+func TestServerMethodNotFound(t *testing.T) {
+	store := setupTestStore(t)
+	server := NewServer(store, nil)
+
+	input := `{"jsonrpc":"2.0","id":1,"method":"unknown/method"}`
+
+	resp := runRequest(t, server, input)
+
+	if resp.Error == nil {
+		t.Fatal("Expected error for unknown method")
+	}
+
+	if resp.Error.Code != MethodNotFound {
+		t.Errorf("Error code = %d, want %d", resp.Error.Code, MethodNotFound)
+	}
+}
+
+func TestServerParseError(t *testing.T) {
+	store := setupTestStore(t)
+	server := NewServer(store, nil)
+
+	input := `not valid json`
+
+	resp := runRequest(t, server, input)
+
+	if resp.Error == nil {
+		t.Fatal("Expected parse error")
+	}
+
+	if resp.Error.Code != ParseError {
+		t.Errorf("Error code = %d, want %d", resp.Error.Code, ParseError)
+	}
+}
+
+func TestServerNotification(t *testing.T) {
+	store := setupTestStore(t)
+	server := NewServer(store, nil)
+
+	// Notification (no response expected)
+	input := `{"jsonrpc":"2.0","method":"notifications/initialized"}`
+
+	var output bytes.Buffer
+	ctx := context.Background()
+	err := server.Run(ctx, strings.NewReader(input+"\n"), &output)
+	if err != nil && err != io.EOF {
+		t.Fatalf("Run failed: %v", err)
+	}
+
+	// Should not produce any output for notifications
+	if output.Len() > 0 {
+		t.Errorf("Expected no output for notification, got: %s", output.String())
+	}
+}
+
+// Helper functions
+
+func setupTestStore(t *testing.T) database.Store {
+	t.Helper()
+
+	store, err := database.NewSQLiteStore(":memory:")
+	if err != nil {
+		t.Fatalf("Failed to create store: %v", err)
+	}
+
+	if err := store.Initialize(context.Background()); err != nil {
+		t.Fatalf("Failed to initialize store: %v", err)
+	}
+
+	t.Cleanup(func() {
+		store.Close()
+	})
+
+	return store
+}
+
+func runRequest(t *testing.T, server *Server, input string) *Response {
+	t.Helper()
+
+	var output bytes.Buffer
+	ctx := context.Background()
+
+	// Run with input terminated by newline
+	err := server.Run(ctx, strings.NewReader(input+"\n"), &output)
+	if err != nil && err != io.EOF {
+		t.Fatalf("Run failed: %v", err)
+	}
+
+	if output.Len() == 0 {
+		t.Fatal("Expected response, got empty output")
+	}
+
+	var resp Response
+	if err := json.Unmarshal(output.Bytes(), &resp); err != nil {
+		t.Fatalf("Failed to parse response: %v\nOutput: %s", err, output.String())
+	}
+
+	return &resp
+}