Accept empty stdin (close #2337) (#2346)

[etc/vim.git] / src / black / __init__.py

diff --git a/src/black/__init__.py b/src/black/__init__.py
index a985926afa52384d414e0073e8d7a48c11632b43..8e2123d50cca8b01759d14cda6d4de6b6fb1259a 100644 (file)
--- a/src/black/__init__.py
+++ b/src/black/__init__.py
@@ -803,7 +803,8 @@ def format_stdin_to_stdout(
         )
         if write_back == WriteBack.YES:
             # Make sure there's a newline after the content
-            dst += "" if dst[-1] == "\n" else "\n"
+            if dst and dst[-1] != "\n":
+                dst += "\n"
             f.write(dst)
         elif write_back in (WriteBack.DIFF, WriteBack.COLOR_DIFF):
             now = datetime.utcnow()