diff --git a/tests/run.rbc b/tests/run.rbc
index b40d1c6..d222341 100644
--- a/tests/run.rbc
+++ b/tests/run.rbc
@@ -52,6 +52,11 @@
 assert_eq([], rblf.filter(["a", "", "b"], "f"))
 assert_eq(["", "b"], rblf.filter_out(["a", "" ], ["a", "", "b"] ))
 
+assert_eq("foo.c no_folder", rblf.notdir(["src/foo.c", "no_folder"]))
+assert_eq("foo.c no_folder", rblf.notdir("src/foo.c no_folder"))
+assert_eq("", rblf.notdir("/"))
+assert_eq("", rblf.notdir(""))
+
 (globals, config, globals_base) = rblf.product_configuration("test/device", init, version_defaults)
 assert_eq(
     {