diff --git a/tests/test_editblock.py b/tests/test_editblock.py
index bed2a5f18..6aea04124 100644
--- a/tests/test_editblock.py
+++ b/tests/test_editblock.py
@@ -1,11 +1,26 @@
 # flake8: noqa: E501
 
+import tempfile
 import unittest
+from pathlib import Path
+from unittest.mock import MagicMock, patch
 
+from aider import models
+from aider.coders import Coder
 from aider.coders import editblock_coder as eb
+from aider.dump import dump  # noqa: F401
+from aider.io import InputOutput
 
 
 class TestUtils(unittest.TestCase):
+    def setUp(self):
+        self.patcher = patch("aider.coders.base_coder.check_model_availability")
+        self.mock_check = self.patcher.start()
+        self.mock_check.return_value = True
+
+    def tearDown(self):
+        self.patcher.stop()
+
     def test_replace_most_similar_chunk(self):
         whole = "This is a sample text.\nAnother line of text.\nYet another line.\n"
         part = "This is a sample text"
@@ -223,6 +238,42 @@ These changes replace the `subprocess.run` patches with `subprocess.check_output
         result = eb.replace_part_with_missing_leading_whitespace(whole, part, replace)
         self.assertEqual(result, expected_output)
 
+    def test_choose_fence(self):
+        # Create a few temporary files
+        _, file1 = tempfile.mkstemp()
+
+        with open(file1, "w", encoding="utf-8") as f:
+            f.write("one\ntwo\nthree\n")
+
+        files = [file1]
+
+        # Initialize the Coder object with the mocked IO and mocked repo
+        coder = Coder.create(
+            models.GPT4, "diff", io=InputOutput(), openai_api_key="fake_key", fnames=files
+        )
+
+        def mock_send(*args, **kwargs):
+            coder.partial_response_content = f"""
+Do this:
+
+{Path(file1).name}
+<<<<<<< ORIGINAL
+two
+=======
+new
+>>>>>>> UPDATED
+
+"""
+            coder.partial_response_function_call = dict()
+
+        coder.send = MagicMock(side_effect=mock_send)
+
+        # Call the run method with a message
+        coder.run(with_message="hi")
+
+        content = open(file1, encoding="utf-8").read()
+        self.assertEqual(content, "one\nnew\nthree\n")
+
 
 if __name__ == "__main__":
     unittest.main()