allow connecting with existing mqttoptions

src/lib.rs

@@ -67,7 +67,12 @@ impl TasmotaClient {
         if let Some((username, password)) = credentials {
             mqtt_opts.set_credentials(username, password);
         }
-        let mqtt = MqttHelper::connect(mqtt_opts)?;
+        Self::from_mqtt_options(mqtt_opts).await
+    }
+
+    /// Connect to an MQTT server using an existing [`MqttOptions`].
+    pub async fn from_mqtt_options(options: MqttOptions) -> Result<Self> {
+        let mqtt = MqttHelper::connect(options);
 
         let mut lwt = mqtt.subscribe("tele/+/LWT".into()).await?;
 

src/mqtt.rs

@@ -17,7 +17,7 @@ pub struct MqttHelper {
 }
 
 impl MqttHelper {
-    pub fn connect(opts: MqttOptions) -> Result<Self> {
+    pub fn connect(opts: MqttOptions) -> Self {
         let (client, event_loop) = AsyncClient::new(opts, 10);
 
         let listeners = Arc::<Mutex<Vec<(String, Sender<_>)>>>::default();
@@ -55,7 +55,7 @@ impl MqttHelper {
             }
         });
 
-        Ok(Self { client, listeners })
+        Self { client, listeners }
     }
 
     pub async fn send<B: Serialize>(&self, topic: &str, body: &B) -> Result<()> {