feat: update metadata property in RequestContext to use type hints and add tests

Author: fernando-torres-blip-ai

src/a2a/server/agent_execution/context.py

@@ -1,4 +1,5 @@
 import uuid
+from typing import Any
 
 from a2a.server.context import ServerCallContext
 from a2a.types import (
@@ -135,7 +136,7 @@ def call_context(self) -> ServerCallContext | None:
         return self._call_context
 
     @property
-    def metadata(self) -> dict:
+    def metadata(self) -> dict[str, Any]:
         """Metadata associated with the request, if available."""
         if not self._params:
             return {}

tests/server/agent_execution/test_context.py

@@ -211,6 +211,17 @@ def test_message_property_with_params(self, mock_params):
         context = RequestContext(request=mock_params)
         assert context.message == mock_params.message
 
+    def test_metadata_property_without_content(self):
+        """Test metadata property returns empty dict when no content are provided."""
+        context = RequestContext()
+        assert context.metadata == {}
+
+    def test_metadata_property_with_content(self, mock_params):
+        """Test metadata property returns the metadata from params."""
+        mock_params.metadata = {'key': 'value'}
+        context = RequestContext(request=mock_params)
+        assert context.metadata == {'key': 'value'}
+
     def test_init_with_existing_ids_in_message(self, mock_message, mock_params):
         """Test initialization with existing IDs in the message."""
         mock_message.taskId = 'existing-task-id'