[ISSUE mxsm#399]✅Add test case for topic_sys_flag🚀

Author: Mark32-ship

rocketmq-common/src/common/sys_flag/topic_sys_flag.rs

@@ -52,3 +52,51 @@ pub fn clear_unit_sub_flag(sys_flag: u32) -> u32 {
 pub fn has_unit_sub_flag(sys_flag: u32) -> bool {
     (sys_flag & FLAG_UNIT_SUB) == FLAG_UNIT_SUB
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn build_sys_flag_sets_correct_flags() {
+        assert_eq!(build_sys_flag(true, false), FLAG_UNIT);
+        assert_eq!(build_sys_flag(false, true), FLAG_UNIT_SUB);
+        assert_eq!(build_sys_flag(true, true), FLAG_UNIT | FLAG_UNIT_SUB);
+    }
+
+    #[test]
+    fn set_unit_flag_sets_correct_flag() {
+        let sys_flag = 0;
+        assert_eq!(set_unit_flag(sys_flag), FLAG_UNIT);
+    }
+
+    #[test]
+    fn clear_unit_flag_clears_correct_flag() {
+        let sys_flag = FLAG_UNIT;
+        assert_eq!(clear_unit_flag(sys_flag), 0);
+    }
+
+    #[test]
+    fn has_unit_flag_returns_correct_value() {
+        assert!(has_unit_flag(FLAG_UNIT));
+        assert!(!has_unit_flag(FLAG_UNIT_SUB));
+    }
+
+    #[test]
+    fn set_unit_sub_flag_sets_correct_flag() {
+        let sys_flag = 0;
+        assert_eq!(set_unit_sub_flag(sys_flag), FLAG_UNIT_SUB);
+    }
+
+    #[test]
+    fn clear_unit_sub_flag_clears_correct_flag() {
+        let sys_flag = FLAG_UNIT_SUB;
+        assert_eq!(clear_unit_sub_flag(sys_flag), 0);
+    }
+
+    #[test]
+    fn has_unit_sub_flag_returns_correct_value() {
+        assert!(has_unit_sub_flag(FLAG_UNIT_SUB));
+        assert!(!has_unit_sub_flag(FLAG_UNIT));
+    }
+}