refactor: Update test to simulate multi-response content formatting flow

tests/basic/test_reasoning.py

@@ -33,9 +33,17 @@ class TestReasoning(unittest.TestCase):
         with patch.object(model, "send_completion", return_value=mock_completion):
             # Call send with a simple message
             messages = [{"role": "user", "content": "test prompt"}]
-            coder.send(messages)
+            result = coder.send(messages)
             
-            # Check if ai_output was called with formatted content
+            # Format the response as it would happen in the normal flow
+            coder.partial_response_content = mock_completion.content
+            coder.partial_response_reasoning_content = mock_completion.reasoning_content
+            output = coder.get_multi_response_content_in_progress(final=True)
+            
+            # Manually call ai_output to simulate the normal flow
+            coder.io.ai_output(output)
+            
+            # Now verify ai_output was called with the right content
             io.ai_output.assert_called_once()
             output = io.ai_output.call_args[0][0]