aider: Added a test function to test the WholeFileCoder's update_files method.

# Context:
USER: make a test for `WholeFileCoder`.updated_files
ASSISTANT: To create a test for the `WholeFileCoder`'s `update_files` method, we will add a new test function in the `tests/test_wholefile.py` file. Here's the test function:

```python
tests/test_wholefile.py
<<<<<<< ORIGINAL

=======
import os
from pathlib import Path
import tempfile
import unittest

from aider.coders.wholefile_coder import WholeFileCoder
from aider.io import InputOutput

class TestWholeFileCoder(unittest.TestCase):
    def test_update_files(self):
        with tempfile.TemporaryDirectory() as temp_dir:
            # Create a sample file in the temporary directory
            sample_file = os.path.join(temp_dir, "sample.txt")
            with open(sample_file, "w") as f:
                f.write("Original content\n")

            # Initialize WholeFileCoder with the temporary directory
            io = InputOutput()
            coder = WholeFileCoder(root=temp_dir, io=io)

            # Set the partial response content with the updated content
            coder.partial_response_content = f"{sample_file}\n```\nUpdated content\n```"

            # Call update_files method
            edited_files = coder.update_files()

            # Check if the sample file was updated
            self.assertIn("sample.txt", edited_files)

            # Check if the content of the sample file was updated
            with open(sample_file, "r") as f:
                updated_content = f.read()
            self.assertEqual(updated_content, "Updated content\n")

if __name__ == "__main__":
    unittest.main()
>>>>>>> UPDATED
```

This test function creates a temporary directory with a sample file, initializes a `WholeFileCoder` instance with the temporary directory, sets the partial response content with the updated content, calls the `update_files` method, and checks if the sample file was updated correctly.

tests/test_wholefile.py

@@ -0,0 +1,36 @@
+import os
+from pathlib import Path
+import tempfile
+import unittest
+
+from aider.coders.wholefile_coder import WholeFileCoder
+from aider.io import InputOutput
+
+class TestWholeFileCoder(unittest.TestCase):
+    def test_update_files(self):
+        with tempfile.TemporaryDirectory() as temp_dir:
+            # Create a sample file in the temporary directory
+            sample_file = os.path.join(temp_dir, "sample.txt")
+            with open(sample_file, "w") as f:
+                f.write("Original content\n")
+
+            # Initialize WholeFileCoder with the temporary directory
+            io = InputOutput()
+            coder = WholeFileCoder(root=temp_dir, io=io)
+
+            # Set the partial response content with the updated content
+            coder.partial_response_content = f"{sample_file}\n```\nUpdated content\n```"
+
+            # Call update_files method
+            edited_files = coder.update_files()
+
+            # Check if the sample file was updated
+            self.assertIn("sample.txt", edited_files)
+
+            # Check if the content of the sample file was updated
+            with open(sample_file, "r") as f:
+                updated_content = f.read()
+            self.assertEqual(updated_content, "Updated content\n")
+
+if __name__ == "__main__":
+    unittest.main()