Use format macro instead of directly concating

src/config.rs

@@ -140,7 +140,7 @@ impl PresenceDeviceConfig {
 
             // @TODO This is not perfect, if the topic is some/+/thing/# this will fail
             let offset = config.presence.topic.find('+').or(config.presence.topic.find('#')).unwrap();
-            let topic = config.presence.topic[..offset].to_owned() + class + "/" + identifier;
+            let topic = format!("{}/{class}/{identifier}", &config.presence.topic[..offset-1]);
             trace!("Setting presence mqtt topic: {topic}");
             self.mqtt = Some(MqttDeviceConfig { topic });
         }
@@ -245,9 +245,9 @@ impl Device {
             Device::AudioSetup { mqtt, mixer, speakers } => {
                 trace!(id = identifier, "AudioSetup [{}]", identifier);
                 // Create the child devices
-                let mixer_id = identifier.to_owned() + ".mixer";
+                let mixer_id = format!("{}.mixer", identifier);
                 let mixer = (*mixer).create(&mixer_id, config, client.clone()).await?;
-                let speakers_id = identifier.to_owned() + ".speakers";
+                let speakers_id = format!("{}.speakers", identifier);
                 let speakers = (*speakers).create(&speakers_id, config, client.clone()).await?;
 
                 AudioSetup::build(&identifier, mqtt, mixer, speakers, client).await

src/debug_bridge.rs

@@ -48,7 +48,7 @@ pub fn start(mut presence_rx: presence::Receiver, mut light_sensor_rx: light_sen
 impl OnPresence for DebugBridge {
     async fn on_presence(&mut self, presence: bool) {
         let message = PresenceMessage::new(presence);
-        let topic = self.topic.clone() + "/presence";
+        let topic = format!("{}/presence", self.topic);
         self.client.publish(topic, rumqttc::QoS::AtLeastOnce, true, serde_json::to_string(&message).unwrap())
             .await
             .map_err(|err| warn!("Failed to update presence on {}/presence: {err}", self.topic))
@@ -60,7 +60,7 @@ impl OnPresence for DebugBridge {
 impl OnDarkness for DebugBridge {
     async fn on_darkness(&mut self, dark: bool) {
         let message = DarknessMessage::new(dark);
-        let topic = self.topic.clone() + "/darkness";
+        let topic = format!("{}/darkness", self.topic);
         self.client.publish(topic, rumqttc::QoS::AtLeastOnce, true, serde_json::to_string(&message).unwrap())
             .await
             .map_err(|err| warn!("Failed to update presence on {}/presence: {err}", self.topic))

src/devices/audio_setup.rs

@@ -23,11 +23,13 @@ pub struct AudioSetup {
 impl AudioSetup {
     pub async fn build(identifier: &str, mqtt: MqttDeviceConfig, mixer: DeviceBox, speakers: DeviceBox, client: AsyncClient) -> Result<Self, DeviceError> {
         // We expect the children devices to implement the OnOff trait
+        let mixer_id = mixer.get_id().to_owned();
         let mixer = AsOnOff::consume(mixer)
-            .ok_or_else(|| DeviceError::OnOffExpected(identifier.to_owned() + ".mixer"))?;
+            .ok_or_else(|| DeviceError::OnOffExpected(mixer_id))?;
 
+        let speakers_id = speakers.get_id().to_owned();
         let speakers = AsOnOff::consume(speakers)
-            .ok_or_else(|| DeviceError::OnOffExpected(identifier.to_owned() + ".speakers"))?;
+            .ok_or_else(|| DeviceError::OnOffExpected(speakers_id))?;
 
         client.subscribe(mqtt.topic.clone(), rumqttc::QoS::AtLeastOnce).await?;
 

src/devices/ikea_outlet.rs

@@ -37,10 +37,11 @@ impl IkeaOutlet {
 async fn set_on(client: AsyncClient, topic: &str, on: bool) {
     let message = OnOffMessage::new(on);
 
+    let topic = format!("{}/set", topic);
     // @TODO Handle potential errors here
-    client.publish(topic.to_owned() + "/set", rumqttc::QoS::AtLeastOnce, false, serde_json::to_string(&message).unwrap())
+    client.publish(topic.clone(), rumqttc::QoS::AtLeastOnce, false, serde_json::to_string(&message).unwrap())
         .await
-        .map_err(|err| warn!("Failed to update state on {topic}/set: {err}"))
+        .map_err(|err| warn!("Failed to update state on {topic}: {err}"))
         .ok();
 }