added more helper func, cfg validation and testing

src/output.rs

@@ -10,3 +10,55 @@ pub struct WaybarOutput {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub percentage: Option<u8>,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_full_output_serialization() {
+        let output = WaybarOutput {
+            text: "CPU: 50%".to_string(),
+            tooltip: Some("Details".to_string()),
+            class: Some("normal".to_string()),
+            percentage: Some(50),
+        };
+        let json = serde_json::to_string(&output).unwrap();
+        let val: serde_json::Value = serde_json::from_str(&json).unwrap();
+        assert_eq!(val["text"], "CPU: 50%");
+        assert_eq!(val["tooltip"], "Details");
+        assert_eq!(val["class"], "normal");
+        assert_eq!(val["percentage"], 50);
+    }
+
+    #[test]
+    fn test_optional_fields_omitted() {
+        let output = WaybarOutput {
+            text: "test".to_string(),
+            tooltip: None,
+            class: None,
+            percentage: None,
+        };
+        let json = serde_json::to_string(&output).unwrap();
+        let val: serde_json::Value = serde_json::from_str(&json).unwrap();
+        assert_eq!(val["text"], "test");
+        assert!(val.get("tooltip").is_none());
+        assert!(val.get("class").is_none());
+        assert!(val.get("percentage").is_none());
+    }
+
+    #[test]
+    fn test_partial_optional_fields() {
+        let output = WaybarOutput {
+            text: "test".to_string(),
+            tooltip: Some("tip".to_string()),
+            class: None,
+            percentage: Some(75),
+        };
+        let json = serde_json::to_string(&output).unwrap();
+        let val: serde_json::Value = serde_json::from_str(&json).unwrap();
+        assert_eq!(val["tooltip"], "tip");
+        assert!(val.get("class").is_none());
+        assert_eq!(val["percentage"], 75);
+    }
+}