Fix the case trailer without newline

cf0b413ef8b794ef6e7436f22fd5a998050dada9

1 files changed, 10 insertions, 0 deletions

diff --git a/tool/test/test_sync_default_gems.rb b/tool/test/test_sync_default_gems.rb
index 602598c3e3..3987b1bec5 100755
--- a/tool/test/test_sync_default_gems.rb
+++ b/tool/test/test_sync_default_gems.rb
@@ -62,5 +62,15 @@ module Test_SyncDefaultGems
       ]
       assert_message_filter(expected, trailers, [expected, "", trailers, ""].join("\n"))
     end
+
+    def test_co_authored_by_no_newline
+      expected = [
+        "commit something",
+      ]
+      trailers = [
+        "Co-Authored-By: git <git@ruby-lang.org>",
+      ]
+      assert_message_filter(expected, trailers, [expected, "", trailers].join("\n"))
+    end
   end
 end