Output something when no files are reformatted (#190)

[etc/vim.git] / tests / test_black.py

diff --git a/tests/test_black.py b/tests/test_black.py
index 02926d1ae4a9fb5248390a35a2c57ceda8539f67..5e17faf1f5f6ee48c3e7e593984dd6d564b1c971 100644 (file)
--- a/tests/test_black.py
+++ b/tests/test_black.py
@@ -636,6 +636,12 @@ class BlackTestCase(unittest.TestCase):
             )
             self.assertEqual(result.exit_code, 1)
 
+    def test_no_files(self) -> None:
+        with cache_dir():
+            # Without an argument, black exits with error code 0.
+            result = CliRunner().invoke(black.main, [])
+            self.assertEqual(result.exit_code, 0)
+
     def test_read_cache_line_lengths(self) -> None:
         with cache_dir() as workspace:
             path = (workspace / "file.py").resolve()