[session-resources] fixes

Author: jaredly

server/server.go

@@ -2,10 +2,12 @@
 package server
 
 import (
+	"cmp"
 	"context"
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
+	"maps"
 	"slices"
 	"sort"
 	"sync"
@@ -826,20 +828,9 @@ func (s *MCPServer) handleListResources(
 	request mcp.ListResourcesRequest,
 ) (*mcp.ListResourcesResult, *requestError) {
 	s.resourcesMu.RLock()
-	resources := make([]mcp.Resource, 0, len(s.resources))
-
-	// Get all resource URIs for consistent ordering
-	resourceURIs := make([]string, 0, len(s.resources))
-	for uri := range s.resources {
-		resourceURIs = append(resourceURIs, uri)
-	}
-
-	// Sort the resource URIs for consistent ordering
-	sort.Strings(resourceURIs)
-
-	// Add resources in sorted order
-	for _, uri := range resourceURIs {
-		resources = append(resources, s.resources[uri].resource)
+	resourceMap := make(map[string]mcp.Resource, len(s.resources))
+	for uri, entry := range s.resources {
+		resourceMap[uri] = entry.resource
 	}
 	s.resourcesMu.RUnlock()
 
@@ -848,34 +839,19 @@ func (s *MCPServer) handleListResources(
 	if session != nil {
 		if sessionWithResources, ok := session.(SessionWithResources); ok {
 			if sessionResources := sessionWithResources.GetSessionResources(); sessionResources != nil {
-				// Override or add session-specific resources
-				// We need to create a map first to merge the resources properly
-				resourceMap := make(map[string]mcp.Resource)
-
-				// Add global resources first
-				for _, resource := range resources {
-					resourceMap[resource.URI] = resource
-				}
-
-				// Then override with session-specific resources
+				// Merge session-specific resources with global resources
 				for uri, serverResource := range sessionResources {
 					resourceMap[uri] = serverResource.Resource
 				}
-
-				// Convert back to slice
-				resources = make([]mcp.Resource, 0, len(resourceMap))
-				for _, resource := range resourceMap {
-					resources = append(resources, resource)
-				}
-
-				// Sort again to maintain consistent ordering
-				sort.Slice(resources, func(i, j int) bool {
-					return resources[i].URI < resources[j].URI
-				})
 			}
 		}
 	}
 
+	// Sort the resources by name
+	resources := slices.SortedFunc(maps.Values(resourceMap), func(a, b mcp.Resource) int {
+		return cmp.Compare(a.Name, b.Name)
+	})
+
 	// Apply pagination
 	resourcesToReturn, nextCursor, err := listByPagination(
 		ctx,

server/streamable_http.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"maps"
 	"mime"
 	"net/http"
 	"net/http/httptest"
@@ -798,13 +799,17 @@ func newSessionResourcesStore() *sessionResourcesStore {
 func (s *sessionResourcesStore) get(sessionID string) map[string]ServerResource {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
-	return s.resources[sessionID]
+	cloned := make(map[string]ServerResource, len(s.resources[sessionID]))
+	maps.Copy(cloned, s.resources[sessionID])
+	return cloned
 }
 
 func (s *sessionResourcesStore) set(sessionID string, resources map[string]ServerResource) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	s.resources[sessionID] = resources
+	cloned := make(map[string]ServerResource, len(resources))
+	maps.Copy(cloned, resources)
+	s.resources[sessionID] = cloned
 }
 
 func (s *sessionResourcesStore) delete(sessionID string) {
@@ -827,13 +832,17 @@ func newSessionToolsStore() *sessionToolsStore {
 func (s *sessionToolsStore) get(sessionID string) map[string]ServerTool {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
-	return s.tools[sessionID]
+	cloned := make(map[string]ServerTool, len(s.tools[sessionID]))
+	maps.Copy(cloned, s.tools[sessionID])
+	return cloned
 }
 
 func (s *sessionToolsStore) set(sessionID string, tools map[string]ServerTool) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	s.tools[sessionID] = tools
+	cloned := make(map[string]ServerTool, len(tools))
+	maps.Copy(cloned, tools)
+	s.tools[sessionID] = cloned
 }
 
 func (s *sessionToolsStore) delete(sessionID string) {
@@ -886,7 +895,7 @@ func newStreamableHttpSession(sessionID string, toolStore *sessionToolsStore, re
 		sessionID:              sessionID,
 		notificationChannel:    make(chan mcp.JSONRPCNotification, 100),
 		tools:                  toolStore,
-		resources:           resourcesStore,
+		resources:              resourcesStore,
 		logLevels:              levels,
 		samplingRequestChan:    make(chan samplingRequestItem, 10),
 		elicitationRequestChan: make(chan elicitationRequestItem, 10),