Update tests/server/test_id_generator.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: didier-durand

tests/server/test_id_generator.py

@@ -34,9 +34,11 @@ def test_context_mutability(self):
         assert context.task_id == "task_456"
 
     def test_context_validation(self):
-        """Test that context validates field types."""
-        context = IDGeneratorContext(task_id="valid_string")
-        assert isinstance(context.task_id, str)
+        """Test that context raises validation error for invalid types."""
+        from pydantic import ValidationError
+
+        with pytest.raises(ValidationError):
+            IDGeneratorContext(task_id={"not": "a string"})
 
 
 class TestIDGenerator: