cover raw strutils to upcase and downcase

src/plugins/str.rs

@@ -297,6 +297,20 @@ mod tests {
         assert!(strutils.filter(subject).is_err());
     }
 
+    #[test]
+    fn str_downcases() {
+        let mut strutils = Str::new();
+        strutils.for_downcase();
+        assert_eq!("andres", strutils.apply("ANDRES"));
+    }
+
+    #[test]
+    fn str_upcases() {
+        let mut strutils = Str::new();
+        strutils.for_upcase();
+        assert_eq!("ANDRES", strutils.apply("andres"));
+    }
+
     #[test]
     fn str_applies_upcase() {
         let mut strutils = Str::new();