feat: Add test for processing reasoning content in <think> tags

tests/basic/test_reasoning.py

@@ -64,6 +64,71 @@ class TestReasoning(unittest.TestCase):
                 reasoning_pos, main_pos, "Reasoning content should appear before main content"
             )
             
+    def test_send_with_think_tags(self):
+        """Test that <think> tags are properly processed and formatted."""
+        # Setup IO with no pretty
+        io = InputOutput(pretty=False)
+        io.assistant_output = MagicMock()
+
+        # Setup model and coder
+        model = Model("gpt-3.5-turbo")
+        model.remove_reasoning = "think"  # Set to remove <think> tags
+        coder = Coder.create(model, None, io=io, stream=False)
+
+        # Test data
+        reasoning_content = "My step-by-step reasoning process"
+        main_content = "Final answer after reasoning"
+        
+        # Create content with think tags
+        combined_content = f"""<think>
+{reasoning_content}
+</think>
+
+{main_content}"""
+
+        # Mock completion response with think tags in content
+        class MockCompletion:
+            def __init__(self, content):
+                self.content = content
+                # Add required attributes expected by show_send_output
+                self.choices = [MagicMock()]
+                self.choices[0].message.content = content
+                self.choices[0].message.reasoning_content = None  # No separate reasoning_content
+                self.finish_reason = "stop"
+
+        mock_completion = MockCompletion(combined_content)
+
+        # Create a mock hash object
+        mock_hash = MagicMock()
+        mock_hash.hexdigest.return_value = "mock_hash_digest"
+
+        # Mock the model's send_completion method to return the expected tuple format
+        with patch.object(model, "send_completion", return_value=(mock_hash, mock_completion)):
+            # Call send with a simple message
+            messages = [{"role": "user", "content": "test prompt"}]
+            list(coder.send(messages))
+
+            # Now verify ai_output was called with the right content
+            io.assistant_output.assert_called_once()
+            output = io.assistant_output.call_args[0][0]
+
+            dump(output)
+
+            # Output should contain formatted reasoning tags
+            self.assertIn("Thinking ...", output)
+            self.assertIn("... done thinking", output)
+
+            # Output should include both reasoning and main content
+            self.assertIn(reasoning_content, output)
+            self.assertIn(main_content, output)
+
+            # Ensure proper order: reasoning first, then main content
+            reasoning_pos = output.find(reasoning_content)
+            main_pos = output.find(main_content)
+            self.assertLess(
+                reasoning_pos, main_pos, "Reasoning content should appear before main content"
+            )
+
 
 if __name__ == "__main__":
     unittest.main()