diff --git a/tests/test_commands.py b/tests/test_commands.py
index e69de29bb..cf4a5700e 100644
--- a/tests/test_commands.py
+++ b/tests/test_commands.py
@@ -0,0 +1,23 @@
+import os
+import tempfile
+from unittest import TestCase
+from aider.io import InputOutput
+from aider.coder import Coder
+from aider.commands import Commands
+
+class TestCommands(TestCase):
+    def test_cmd_add(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            original_cwd = os.getcwd()
+            os.chdir(tmpdir)
+
+            io = InputOutput()
+            coder = Coder(io)
+            commands = Commands(io, coder)
+
+            commands.cmd_add(['foo.txt', 'bar.txt'])
+
+            self.assertTrue(os.path.exists('foo.txt'))
+            self.assertTrue(os.path.exists('bar.txt'))
+
+            os.chdir(original_cwd)