Merge pull request #913 from jrouaix/tryable_bot

triable bot

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Add `MessageToCopyNotFound` error to `teloxide::errors::ApiError` ([PR 917](https://github.com/teloxide/teloxide/pull/917)) 
+- `Dispatcher::try_dispatch_with_listener` ([PR 913](https://github.com/teloxide/teloxide/pull/913))
 
 ### Fixed
 

crates/teloxide/src/dispatching/dispatcher.rs

@@ -277,7 +277,6 @@ where
     ///  - An update from Telegram;
     ///  - [`crate::types::Me`] (can be used in [`HandlerExt::filter_command`]).
     ///
-    /// [`shutdown`]: ShutdownToken::shutdown
     /// [`HandlerExt::filter_command`]: crate::dispatching::HandlerExt::filter_command
     pub async fn dispatch(&mut self)
     where
@@ -295,19 +294,39 @@ where
     /// `update_listener_error_handler`.
     ///
     /// This method adds the same dependencies as [`Dispatcher::dispatch`].
-    ///
-    /// [`shutdown`]: ShutdownToken::shutdown
     pub async fn dispatch_with_listener<'a, UListener, Eh>(
         &'a mut self,
-        mut update_listener: UListener,
+        update_listener: UListener,
         update_listener_error_handler: Arc<Eh>,
     ) where
         UListener: UpdateListener + 'a,
         Eh: ErrorHandler<UListener::Err> + 'a,
         UListener::Err: Debug,
+    {
+        self.try_dispatch_with_listener(update_listener, update_listener_error_handler)
+            .await
+            .expect("Couldn't prepare dispatching context")
+    }
+
+    /// Same as `dispatch_with_listener` but returns a `Err(_)` instead of
+    /// panicking when the initial telegram api call (`get_me`) fails.
+    ///
+    /// Starts your bot with custom `update_listener` and
+    /// `update_listener_error_handler`.
+    ///
+    /// This method adds the same dependencies as [`Dispatcher::dispatch`].
+    pub async fn try_dispatch_with_listener<'a, UListener, Eh>(
+        &'a mut self,
+        mut update_listener: UListener,
+        update_listener_error_handler: Arc<Eh>,
+    ) -> Result<(), R::Err>
+    where
+        UListener: UpdateListener + 'a,
+        Eh: ErrorHandler<UListener::Err> + 'a,
+        UListener::Err: Debug,
     {
         // FIXME: there should be a way to check if dependency is already inserted
-        let me = self.bot.get_me().send().await.expect("Failed to retrieve 'me'");
+        let me = self.bot.get_me().send().await?;
         self.dependencies.insert(me);
         self.dependencies.insert(self.bot.clone());
 
@@ -360,6 +379,7 @@ where
             .await;
 
         self.state.done();
+        Ok(())
     }
 
     async fn process_update<LErr, LErrHandler>(
@@ -462,9 +482,8 @@ where
         }
     }
 
-    /// Setups the `^C` handler that [`shutdown`]s dispatching.
-    ///
-    /// [`shutdown`]: ShutdownToken::shutdown
+    /// Setups the `^C` handler in order to call [`ShutdownToken::shutdown`]
+    /// when pressed.
     #[cfg(feature = "ctrlc_handler")]
     #[deprecated(since = "0.10.0", note = "use `enable_ctrlc_handler` on builder instead")]
     pub fn setup_ctrlc_handler(&mut self) -> &mut Self {
@@ -472,8 +491,8 @@ where
         self
     }
 
-    /// Returns a shutdown token, which can later be used to shutdown
-    /// dispatching.
+    /// Returns a shutdown token, which can later be used to
+    /// [`ShutdownToken::shutdown`].
     pub fn shutdown_token(&self) -> ShutdownToken {
         self.state.clone()
     }