Fix handling of empty files

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

diff --git a/tests/test_black.py b/tests/test_black.py
index f6952c721ccd0ba64f8c921e3dd10d2a75c1d6c1..e98f019e6808335e5176040e19cd8fcb945b64c0 100644 (file)
--- a/tests/test_black.py
+++ b/tests/test_black.py
@@ -100,6 +100,25 @@ class BlackTestCase(unittest.TestCase):
                 black.err(str(ve))
         self.assertEqual(expected, actual)
 
+    @patch("black.dump_to_file", dump_to_stderr)
+    def test_empty(self) -> None:
+        source = expected = ""
+        actual = fs(source)
+        self.assertFormatEqual(expected, actual)
+        black.assert_equivalent(source, actual)
+        black.assert_stable(source, actual, line_length=ll)
+
+    def test_empty_ff(self) -> None:
+        expected = ""
+        tmp_file = Path(black.dump_to_file())
+        try:
+            self.assertFalse(ff(tmp_file, write_back=black.WriteBack.YES))
+            with open(tmp_file, encoding="utf8") as f:
+                actual = f.read()
+        finally:
+            os.unlink(tmp_file)
+        self.assertFormatEqual(expected, actual)
+
     @patch("black.dump_to_file", dump_to_stderr)
     def test_self(self) -> None:
         source, expected = read_data("test_black")