diff -r 0f4de9c27973 -r 40c7347f6848 tests/test-annotate.t
--- a/tests/test-annotate.t	Thu Mar 15 21:09:37 2018 +0900
+++ b/tests/test-annotate.t	Sat Mar 17 23:34:38 2018 +0900
@@ -105,6 +105,8 @@
 
 several filters can be applied to '{lines}'
 
+  $ hg annotate -T'{lines|json}\n' a
+  [{"line": "a\n", "rev": 0}, {"line": "a\n", "rev": 1}, {"line": "a\n", "rev": 1}]
   $ hg annotate -T'{lines|stringify}' a
   0: a
   1: a