add test for cycle tags

Author: griccardos

src/pure/stack_set.rs

@@ -1309,6 +1309,26 @@ pub mod tests {
 
         assert!(matches!(res, Err(Error::NoScreens)));
     }
+
+
+    #[test_case(true,1,1; "forward")]
+    #[test_case(false,1,3; "backward")]
+    #[test_case(true,4,0; "forward loop to start")]
+    #[test]
+    fn tag_cycle_focuses_correct_tag(forward: bool,count:usize, expected_index: usize) {
+        let mut s = test_stack_set(4,2);
+
+        for _ in 0..count{
+        if forward {
+            s.next_tag()
+        } else {
+            s.previous_tag()
+        }
+    }
+        let tags=s.ordered_tags();
+
+        assert_eq!(s.current_tag(), tags[expected_index]);
+    }
 }
 
 #[cfg(test)]