yangre TEST for pattern, invert-match, files
diff --git a/tests/yangre/files/empty_str_err.txt b/tests/yangre/files/empty_str_err.txt
new file mode 100644
index 0000000..f48a15d
--- /dev/null
+++ b/tests/yangre/files/empty_str_err.txt
@@ -0,0 +1,2 @@
+"[0-9a-fA-F]+"
+