diff --git a/tests/basic/test_editblock.py b/tests/basic/test_editblock.py
index d4bcc89dc..1b099553c 100644
--- a/tests/basic/test_editblock.py
+++ b/tests/basic/test_editblock.py
@@ -16,6 +16,38 @@ class TestUtils(unittest.TestCase):
     def setUp(self):
         self.GPT35 = Model("gpt-3.5-turbo")
 
+    def test_find_filename(self):
+        fence = ("```", "```")
+        valid_fnames = ["file1.py", "file2.py", "dir/file3.py"]
+
+        # Test with filename on a single line
+        lines = ["file1.py", "```"]
+        self.assertEqual(eb.find_filename(lines, fence, valid_fnames), "file1.py")
+
+        # Test with filename and fence on separate lines
+        lines = ["file2.py", "```", "some content"]
+        self.assertEqual(eb.find_filename(lines, fence, valid_fnames), "file2.py")
+
+        # Test with filename in fence
+        lines = ["```python", "file3.py", "```"]
+        self.assertEqual(eb.find_filename(lines, fence, valid_fnames), "dir/file3.py")
+
+        # Test with no valid filename
+        lines = ["```", "invalid_file.py", "```"]
+        self.assertIsNone(eb.find_filename(lines, fence, valid_fnames))
+
+        # Test with multiple fences
+        lines = ["```python", "file1.py", "```", "```", "file2.py", "```"]
+        self.assertEqual(eb.find_filename(lines, fence, valid_fnames), "file2.py")
+
+        # Test with filename having extra characters
+        lines = ["# file1.py", "```"]
+        self.assertEqual(eb.find_filename(lines, fence, valid_fnames), "file1.py")
+
+        # Test with fuzzy matching
+        lines = ["file1_py", "```"]
+        self.assertEqual(eb.find_filename(lines, fence, valid_fnames), "file1.py")
+
     # fuzzy logic disabled v0.11.2-dev
     def __test_replace_most_similar_chunk(self):
         whole = "This is a sample text.\nAnother line of text.\nYet another line.\n"