Add renice

Co-authored-by: Sylvestre Ledru <sylvestre@debian.org>

tests/by-util/test_renice.rs

@@ -0,0 +1,12 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+// spell-checker:ignore (words) symdir somefakedir
+
+use crate::common::util::TestScenario;
+
+#[test]
+fn test_invalid_arg() {
+    new_ucmd!().arg("--definitely-invalid").fails().code_is(1);
+}

tests/tests.rs

@@ -33,6 +33,10 @@ mod test_blockdev;
 #[path = "by-util/test_ctrlaltdel.rs"]
 mod test_ctrlaltdel;
 
+#[cfg(feature = "renice")]
+#[path = "by-util/test_renice.rs"]
+mod test_renice;
+
 #[cfg(feature = "rev")]
 #[path = "by-util/test_rev.rs"]
 mod test_rev;