test: add test to test-project

Author: Cyncrovee

test-project/src/main.rs

@@ -23,3 +23,11 @@ fn main() {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test() {
+        println!("***output test");
+    }
+}