Apply suggestions from the review

- remove `username_from_bot`
- add `username_from_me`

examples/dispatching2_features.rs

@@ -7,7 +7,7 @@ use rand::Rng;
 // dispatching system, which will be deprecated in the future.
 use teloxide::{
     prelude2::*,
-    types::{Dice, Update},
+    types::{Dice, Me, Update},
     utils::command::BotCommands,
 };
 
@@ -26,28 +26,6 @@ async fn main() {
     let handler = Update::filter_message()
         // You can use branching to define multiple ways in which an update will be handled. If the
         // first branch fails, an update will be passed to the second branch, and so on.
-        .branch(
-            // Filtering allow you to filter updates by some condition.
-            dptree::filter(|msg: Message| msg.chat.is_group() || msg.chat.is_supergroup())
-                // An endpoint is the last update handler.
-                .endpoint(|msg: Message, bot: AutoSend<Bot>| async move {
-                    log::info!("Received a message from a group chat.");
-                    bot.send_message(msg.chat.id, "This is a group chat.").await?;
-                    respond(())
-                }),
-        )
-        .branch(
-            // There are some extension filtering functions on `Message`. The following filter will
-            // filter only messages with dices.
-            Message::filter_dice().endpoint(
-                |msg: Message, dice: Dice, bot: AutoSend<Bot>| async move {
-                    bot.send_message(msg.chat.id, format!("Dice value: {}", dice.value))
-                        .reply_to_message_id(msg.id)
-                        .await?;
-                    Ok(())
-                },
-            ),
-        )
         .branch(
             dptree::entry()
                 // Filter commands: the next handlers will receive a parsed `SimpleCommand`.
@@ -74,6 +52,28 @@ async fn main() {
                     }
                 },
             ),
+        )
+        .branch(
+            // Filtering allow you to filter updates by some condition.
+            dptree::filter(|msg: Message| msg.chat.is_group() || msg.chat.is_supergroup())
+                // An endpoint is the last update handler.
+                .endpoint(|msg: Message, bot: AutoSend<Bot>| async move {
+                    log::info!("Received a message from a group chat.");
+                    bot.send_message(msg.chat.id, "This is a group chat.").await?;
+                    respond(())
+                }),
+        )
+        .branch(
+            // There are some extension filtering functions on `Message`. The following filter will
+            // filter only messages with dices.
+            Message::filter_dice().endpoint(
+                |msg: Message, dice: Dice, bot: AutoSend<Bot>| async move {
+                    bot.send_message(msg.chat.id, format!("Dice value: {}", dice.value))
+                        .reply_to_message_id(msg.id)
+                        .await?;
+                    Ok(())
+                },
+            ),
         );
 
     Dispatcher::builder(bot, handler)
@@ -124,6 +124,7 @@ async fn simple_commands_handler(
     bot: AutoSend<Bot>,
     cmd: SimpleCommand,
     cfg: ConfigParameters,
+    me: Me,
 ) -> Result<(), teloxide::RequestError> {
     let text = match cmd {
         SimpleCommand::Help => {
@@ -134,7 +135,7 @@ async fn simple_commands_handler(
                     MaintainerCommands::descriptions()
                 )
             } else if msg.chat.is_group() || msg.chat.is_supergroup() {
-                SimpleCommand::descriptions().username("USERNAME_BOT").to_string()
+                SimpleCommand::descriptions().username_from_me(&me).to_string()
             } else {
                 SimpleCommand::descriptions().to_string()
             }

src/utils/command.rs

@@ -51,16 +51,12 @@
 
 use core::fmt;
 use std::{
-    borrow::Cow,
     error::Error,
     fmt::{Display, Formatter, Write},
 };
 
 use std::marker::PhantomData;
-use teloxide_core::{
-    requests::{Request, Requester},
-    types::{BotCommand, Me},
-};
+use teloxide_core::types::{BotCommand, Me};
 #[cfg(feature = "macros")]
 pub use teloxide_macros::BotCommands;
 
@@ -282,7 +278,7 @@ pub enum ParseError {
 pub struct CommandDescriptions<'a> {
     global_description: Option<&'a str>,
     descriptions: &'a [CommandDescription<'a>],
-    bot_username: Option<Cow<'a, str>>,
+    bot_username: Option<&'a str>,
 }
 
 /// Description of a particular command, used in [`CommandDescriptions`].
@@ -331,21 +327,17 @@ impl<'a> CommandDescriptions<'a> {
     /// );
     /// ```
     pub fn username(self, bot_username: &'a str) -> Self {
-        Self { bot_username: Some(Cow::Borrowed(bot_username)), ..self }
+        Self { bot_username: Some(bot_username), ..self }
     }
 
     /// Sets the username of the bot.
     ///
-    /// This is the same as [`username`], but uses `get_me` method of the bot to
-    /// get the username.
+    /// This is the same as [`username`], but uses value returned from `get_me`
+    /// method to get the username.
     ///
     /// [`username`]: self::CommandDescriptions::username
-    pub async fn username_from_bot(self, bot: &impl Requester) -> CommandDescriptions<'a> {
-        let Me { user, .. } = bot.get_me().send().await.expect("get_me failed");
-        Self {
-            bot_username: Some(Cow::Owned(user.username.expect("Bots must have usernames"))),
-            ..self
-        }
+    pub fn username_from_me(self, me: &'a Me) -> CommandDescriptions<'a> {
+        self.username(me.user.username.as_deref().expect("Bots must have usernames"))
     }
 }