Improve error handling with forward_error macro

Signed-off-by: trivernis <trivernis@protonmail.com>

bot-serenityutils/src/lib.rs

@@ -1,4 +1,5 @@
 pub mod core;
+pub mod ephemeral_message;
 pub mod error;
+pub mod macros;
 pub mod menu;
-pub mod ephemeral_message;

bot-serenityutils/src/macros.rs

@@ -0,0 +1,16 @@
+/// Forwards the error directly to the user
+/// without having to accept it in any handler.
+/// Can only be used in async functions that return a Result.
+#[macro_export]
+macro_rules! forward_error {
+    ($ctx:expr,$channel_id:expr,$result:expr) => {
+        match $result {
+            Err(e) => {
+                use bot_serenityutils::{core::SHORT_TIMEOUT, ephemeral_message::EphemeralMessage};
+                $channel_id.say($ctx, format!("‼️ {}", e)).await?;
+                return Ok(());
+            }
+            Ok(v) => v,
+        }
+    };
+}

src/commands/misc/time.rs

@@ -17,13 +17,13 @@ async fn time(ctx: &Context, msg: &Message, mut args: Args) -> CommandResult {
     let second_timezone = args.single::<String>().ok();
 
     let from_timezone: Tz = if let Some(first) = &first_timezone {
-        first.parse::<Tz>()?
+        forward_error!(ctx, msg.channel_id, first.parse::<Tz>())
     } else {
         Tz::UTC
     };
 
     let to_timezone = if let Some(second) = &second_timezone {
-        second.parse::<Tz>()?
+        forward_error!(ctx, msg.channel_id, second.parse::<Tz>())
     } else {
         Tz::UTC
     };
@@ -33,18 +33,25 @@ async fn time(ctx: &Context, msg: &Message, mut args: Args) -> CommandResult {
     } else {
         let now = Utc::now();
         if second_timezone.is_some() {
-            from_timezone.datetime_from_str(
+            forward_error!(
-                &format!("{} {}:00", now.format("%Y-%m-%d"), &*when),
+                ctx,
-                "%Y-%m-%d %H:%M:%S",
+                msg.channel_id,
-            )?
+                from_timezone.datetime_from_str(
+                    &format!("{} {}:00", now.format("%Y-%m-%d"), &*when),
+                    "%Y-%m-%d %H:%M:%S",
+                )
+            )
         } else {
             let timezone: Tz = "UTC".parse().unwrap();
-            timezone
+            forward_error!(
-                .datetime_from_str(
+                ctx,
+                msg.channel_id,
+                timezone.datetime_from_str(
                     &format!("{} {}:00", now.format("%Y-%m-%d"), &*when),
                     "%Y-%m-%d %H:%M:%S",
-                )?
+                )
-                .with_timezone(&from_timezone)
+            )
+            .with_timezone(&from_timezone)
         }
     };
 

src/commands/music/clear_queue.rs

@@ -23,7 +23,11 @@ async fn clear_queue(ctx: &Context, msg: &Message) -> CommandResult {
     }
     log::debug!("Clearing queue for guild {}", guild.id);
 
-    let queue = get_queue_for_guild(ctx, &guild.id).await?;
+    let queue = forward_error!(
+        ctx,
+        msg.channel_id,
+        get_queue_for_guild(ctx, &guild.id).await
+    );
     {
         let mut queue_lock = queue.lock().await;
         queue_lock.clear();

src/commands/music/current.rs

@@ -19,7 +19,11 @@ async fn current(ctx: &Context, msg: &Message) -> CommandResult {
     let guild = msg.guild(&ctx.cache).await.unwrap();
 
     log::debug!("Displaying current song for queue in {}", guild.id);
-    let queue = get_queue_for_guild(ctx, &guild.id).await?;
+    let queue = forward_error!(
+        ctx,
+        msg.channel_id,
+        get_queue_for_guild(ctx, &guild.id).await
+    );
 
     let current = {
         let queue_lock = queue.lock().await;

src/commands/music/join.rs

@@ -20,10 +20,18 @@ async fn join(ctx: &Context, msg: &Message, mut args: Args) -> CommandResult {
         if is_dj(ctx, guild.id, &msg.author).await? {
             ChannelId(arg)
         } else {
-            get_channel_for_author(&msg.author.id, &guild)?
+            forward_error!(
+                ctx,
+                msg.channel_id,
+                get_channel_for_author(&msg.author.id, &guild)
+            )
         }
     } else {
-        get_channel_for_author(&msg.author.id, &guild)?
+        forward_error!(
+            ctx,
+            msg.channel_id,
+            get_channel_for_author(&msg.author.id, &guild)
+        )
     };
     log::debug!("Joining channel {} for guild {}", channel_id, guild.id);
     join_channel(ctx, channel_id, guild.id).await;

src/commands/music/leave.rs

@@ -23,7 +23,11 @@ async fn leave(ctx: &Context, msg: &Message) -> CommandResult {
     }
 
     let manager = get_voice_manager(ctx).await;
-    let queue = get_queue_for_guild(ctx, &guild.id).await?;
+    let queue = forward_error!(
+        ctx,
+        msg.channel_id,
+        get_queue_for_guild(ctx, &guild.id).await
+    );
     let queue_lock = queue.lock().await;
     let handler = manager.get(guild.id);
 
@@ -31,11 +35,11 @@ async fn leave(ctx: &Context, msg: &Message) -> CommandResult {
         let mut handler_lock = handler.lock().await;
         handler_lock.remove_all_global_events();
     }
-    if let Some(current) = queue_lock.current() {
-        current.stop()?;
-    }
 
     if manager.get(guild.id).is_some() {
+        if let Some(current) = queue_lock.current() {
+            current.stop()?;
+        }
         manager.remove(guild.id).await?;
         EphemeralMessage::create(&ctx.http, msg.channel_id, SHORT_TIMEOUT, |m| {
             m.content("👋 Left the Voice Channel")

src/commands/music/lyrics.rs

@@ -16,7 +16,11 @@ async fn lyrics(ctx: &Context, msg: &Message) -> CommandResult {
     let guild = msg.guild(&ctx.cache).await.unwrap();
     log::debug!("Fetching lyrics for song playing in {}", guild.id);
 
-    let queue = get_queue_for_guild(ctx, &guild.id).await?;
+    let queue = forward_error!(
+        ctx,
+        msg.channel_id,
+        get_queue_for_guild(ctx, &guild.id).await
+    );
     let queue_lock = queue.lock().await;
 
     if let Some(current) = queue_lock.current() {

src/commands/music/mod.rs

@@ -194,7 +194,7 @@ fn get_channel_for_author(author_id: &UserId, guild: &Guild) -> BotResult<Channe
         .voice_states
         .get(author_id)
         .and_then(|voice_state| voice_state.channel_id)
-        .ok_or(BotError::from("Not in a voice channel."))
+        .ok_or(BotError::from("You're not in a Voice Channel"))
 }
 
 /// Returns the voice manager from the context
@@ -216,7 +216,7 @@ pub(crate) async fn get_queue_for_guild(
     let queue = store
         .music_queues
         .get(guild_id)
-        .ok_or(BotError::from("No queue for server"))?
+        .ok_or(BotError::from("I'm not in a Voice Channel"))?
         .clone();
     Ok(queue)
 }

src/commands/music/move_song.rs

@@ -28,7 +28,11 @@ async fn move_song(ctx: &Context, msg: &Message, mut args: Args) -> CommandResul
         return Ok(());
     }
     {
-        let queue = get_queue_for_guild(ctx, &guild.id).await?;
+        let queue = forward_error!(
+            ctx,
+            msg.channel_id,
+            get_queue_for_guild(ctx, &guild.id).await
+        );
         let mut queue_lock = queue.lock().await;
         queue_lock.move_position(pos1, pos2);
     }

src/commands/music/pause.rs

@@ -22,7 +22,11 @@ async fn pause(ctx: &Context, msg: &Message) -> CommandResult {
         return Ok(());
     }
 
-    let queue = get_queue_for_guild(ctx, &guild.id).await?;
+    let queue = forward_error!(
+        ctx,
+        msg.channel_id,
+        get_queue_for_guild(ctx, &guild.id).await
+    );
     let mut queue_lock = queue.lock().await;
 
     if let Some(_) = queue_lock.current() {

src/commands/music/play.rs

@@ -33,7 +33,11 @@ async fn play(ctx: &Context, msg: &Message, args: Args) -> CommandResult {
         handler = Some(join_channel(ctx, channel_id, guild.id).await);
     }
 
-    let handler_lock = handler.ok_or(CommandError::from("Not in a voice channel"))?;
+    let handler_lock = forward_error!(
+        ctx,
+        msg.channel_id,
+        handler.ok_or(CommandError::from("I'm not in a voice channel"))
+    );
 
     let songs = get_songs_for_query(&ctx, msg, query).await?;
 

src/commands/music/play_next.rs

@@ -35,7 +35,11 @@ async fn play_next(ctx: &Context, msg: &Message, args: Args) -> CommandResult {
         handler = Some(join_channel(ctx, channel_id, guild.id).await);
     }
 
-    let handler = handler.ok_or(CommandError::from("Not in a voice channel"))?;
+    let handler = forward_error!(
+        ctx,
+        msg.channel_id,
+        handler.ok_or(CommandError::from("I'm not in a voice channel"))
+    );
 
     let mut songs = get_songs_for_query(&ctx, msg, query).await?;
 

src/commands/music/queue.rs

@@ -23,7 +23,11 @@ async fn queue(ctx: &Context, msg: &Message, mut args: Args) -> CommandResult {
         .map(|s| s.unwrap().to_lowercase())
         .collect::<Vec<String>>();
 
-    let queue = get_queue_for_guild(ctx, &guild.id).await?;
+    let queue = forward_error!(
+        ctx,
+        msg.channel_id,
+        get_queue_for_guild(ctx, &guild.id).await
+    );
     let queue_lock = queue.lock().await;
     let songs: Vec<(usize, Song)> = queue_lock
         .entries()

src/commands/music/remove_song.rs

@@ -27,7 +27,11 @@ async fn remove_song(ctx: &Context, msg: &Message, mut args: Args) -> CommandRes
         return Ok(());
     }
     {
-        let queue = get_queue_for_guild(ctx, &guild.id).await?;
+        let queue = forward_error!(
+            ctx,
+            msg.channel_id,
+            get_queue_for_guild(ctx, &guild.id).await
+        );
         let mut queue_lock = queue.lock().await;
         queue_lock.remove(pos);
     }

src/commands/music/shuffle.rs

@@ -22,7 +22,11 @@ async fn shuffle(ctx: &Context, msg: &Message) -> CommandResult {
         msg.channel_id.say(ctx, "Requires DJ permissions").await?;
         return Ok(());
     }
-    let queue = get_queue_for_guild(ctx, &guild.id).await?;
+    let queue = forward_error!(
+        ctx,
+        msg.channel_id,
+        get_queue_for_guild(ctx, &guild.id).await
+    );
     {
         let mut queue_lock = queue.lock().await;
         queue_lock.shuffle();

src/commands/music/skip.rs

@@ -21,7 +21,11 @@ async fn skip(ctx: &Context, msg: &Message) -> CommandResult {
         return Ok(());
     }
     log::debug!("Skipping song for guild {}", guild.id);
-    let queue = get_queue_for_guild(ctx, &guild.id).await?;
+    let queue = forward_error!(
+        ctx,
+        msg.channel_id,
+        get_queue_for_guild(ctx, &guild.id).await
+    );
     let queue_lock = queue.lock().await;
 
     if let Some(current) = queue_lock.current() {

src/main.rs

@@ -1,6 +1,9 @@
 use crate::client::get_client;
 use crate::utils::logging::init_logger;
 
+#[macro_use]
+extern crate bot_serenityutils;
+
 pub mod client;
 mod commands;
 pub mod handler;