diff --git a/tests/test_source_repo_flattener.py b/tests/test_source_repo_flattener.py
index e5b0e7c..6db555e 100644
--- a/tests/test_source_repo_flattener.py
+++ b/tests/test_source_repo_flattener.py
@@ -1,6 +1,10 @@
 import os
 import tempfile
+import shutil
+from unittest.mock import patch
+from git import Repo
 from coderoller.source_repo_flattener import flatten_repo
+from coderoller.flatten_repo import main
 
 
 def test_flatten_repo():
@@ -82,3 +86,67 @@ def test_hidden_files_and_directories():
         assert (
             ".hidden_file.py" not in flattened_content
         ), "Hidden file should be excluded"
+
+
+@patch.object(Repo, "clone_from")
+def test_flatten_repo_from_git(mock_clone_from):
+    with tempfile.TemporaryDirectory() as temp_dir:
+        # Mock the clone_from method to copy a local repository structure instead
+        def mock_clone(repo_url, to_path):
+            shutil.copytree(temp_dir, to_path, dirs_exist_ok=True)
+
+        mock_clone_from.side_effect = mock_clone
+
+        # Create a mock repository structure
+        os.makedirs(os.path.join(temp_dir, "src"))
+
+        readme_content = "# This is the README"
+        with open(os.path.join(temp_dir, "README.md"), "w") as f:
+            f.write(readme_content)
+
+        python_content = 'print("Hello, World!")'
+        with open(os.path.join(temp_dir, "src", "main.py"), "w") as f:
+            f.write(python_content)
+
+        json_content = '{"key": "value"}'
+        with open(os.path.join(temp_dir, "config.json"), "w") as f:
+            f.write(json_content)
+
+        # Test the CLI with a mock GitHub URL
+        with patch(
+            "sys.argv", ["coderoller-flatten-repo", "https://github.com/mock/repo.git"]
+        ):
+            main()
+
+        # Check if the flattened file is created
+        flattened_file_path = os.path.join(os.getcwd(), "repo.flat.md")
+        assert os.path.exists(flattened_file_path), "Flattened file was not created"
+
+        with open(flattened_file_path, "r") as f:
+            flattened_content = f.read()
+
+        # Check if the README content is included
+        assert "## README" in flattened_content, "README section is missing"
+        assert (
+            "```markdown" in flattened_content
+        ), "README content is not properly formatted"
+        assert readme_content in flattened_content, "README content is incorrect"
+
+        # Check if the Python file content is included
+        assert (
+            "## File: src/main.py" in flattened_content
+        ), "Python file section is missing"
+        assert (
+            "```python" in flattened_content
+        ), "Python content is not properly formatted"
+        assert python_content in flattened_content, "Python content is incorrect"
+
+        # Check if the JSON file content is included
+        assert (
+            "## File: config.json" in flattened_content
+        ), "JSON file section is missing"
+        assert "```json" in flattened_content, "JSON content is not properly formatted"
+        assert json_content in flattened_content, "JSON content is incorrect"
+
+        # Clean up the flattened file
+        os.remove(flattened_file_path)