feat: use thiserror for better error handling

Cargo.lock

@@ -617,6 +617,7 @@ dependencies = [
  "clap",
  "console-subscriber",
  "once_cell",
+ "thiserror",
  "tokio",
  "tracing",
  "tracing-subscriber",
@@ -1089,6 +1090,26 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bf256ce5efdfa370213c1dabab5935a12e49f2c58d15e9eac2870d3b4f27263"
 
+[[package]]
+name = "thiserror"
+version = "2.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f63587ca0f12b72a0600bcba1d40081f830876000bb46dd2337a3051618f4fc8"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "2.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ff15c8ecd7de3849db632e14d18d2571fa09dfc5ed93479bc4485c7a517c913"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "thread_local"
 version = "1.1.9"

Cargo.toml

@@ -4,7 +4,6 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-anyhow = "1.0.100"
 async-trait = "0.1.89"
 clap = { version = "4.5.48", features = ["derive"] }
 once_cell = "1.21.3"
@@ -12,6 +11,8 @@ tokio = { version = "1.47.1", features = ["full"] }
 console-subscriber = { version = "0.4.1", optional = true }
 tracing = "0.1.41"
 tracing-subscriber = "0.3.20"
+thiserror = "2.0.17"
+anyhow = "1.0.100"
 
 [features]
 tokio-console = ["tokio/tracing", "console-subscriber"]

src/channels.rs

@@ -1,9 +1,8 @@
 use std::collections::BTreeSet;
 
-use anyhow::Result;
 use tokio::{io::BufWriter, net::TcpStream};
 
-use crate::{sender::IrcResponseCodes, user::User};
+use crate::{error_structs::SenderError, sender::IrcResponseCodes, user::User};
 
 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
 pub struct Channel {
@@ -28,7 +27,7 @@ impl Channel {
         user: User,
         writer: &mut BufWriter<TcpStream>,
         hostname: &str,
-    ) -> Result<()> {
+    ) -> Result<(), SenderError> {
         let mut members = Vec::new();
 
         for member in self.clone().joined_users {
@@ -58,7 +57,7 @@ impl Channel {
         user: User,
         writer: &mut BufWriter<TcpStream>,
         hostname: &str,
-    ) -> Result<()> {
+    ) -> Result<(), SenderError> {
         IrcResponseCodes::NoTopic
             .into_irc_response(
                 user.nickname.clone().unwrap(),

src/commands/mod.rs

@@ -1,7 +1,6 @@
 #![allow(dead_code)]
 use std::collections::HashMap;
 
-use anyhow::{Result, anyhow};
 use async_trait::async_trait;
 use tokio::{io::BufWriter, net::TcpStream, sync::broadcast::Sender};
 
@@ -11,6 +10,7 @@ use crate::{
     commands::{
         cap::Cap, join::Join, nick::Nick, ping::Ping, privmsg::PrivMsg, user::User as UserHandler,
     },
+    error_structs::CommandExecError,
     messages::Message,
     sender::IrcResponse,
     user::User,
@@ -94,7 +94,7 @@ impl IrcCommand {
         writer: &mut BufWriter<TcpStream>,
         hostname: &str,
         user_state: &mut User,
-    ) -> Result<()> {
+    ) -> Result<(), CommandExecError> {
         let mut command_map: HashMap<String, &dyn IrcHandler> = HashMap::new();
         let broadcast_sender = SENDER.lock().await.clone().unwrap();
 
@@ -111,7 +111,7 @@ impl IrcCommand {
         let command_to_execute = command_map
             .get(&self.command.to_uppercase())
             .map(|v| *v)
-            .ok_or(anyhow!("unknown command!"))?;
+            .ok_or(CommandExecError::NonexistantCommand)?;
 
         let action = command_to_execute
             .handle(

src/error_structs.rs

@@ -0,0 +1,43 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum HandlerError {
+    #[error("std::io error")]
+    StdIoError(#[from] std::io::Error),
+}
+
+#[derive(Error, Debug)]
+pub enum ListenerError {
+    #[error("connection error")]
+    ConnectionError,
+
+    #[error("user has not identified yet")]
+    UserIsUnidentified,
+}
+
+#[derive(Error, Debug)]
+pub enum SenderError {
+    #[error("std::io error")]
+    StdIoError(#[from] std::io::Error),
+}
+
+#[derive(Error, Debug)]
+pub enum CommandExecError {
+    #[error("command does not exist")]
+    NonexistantCommand,
+}
+
+// Conversion impls here
+impl From<SenderError> for ListenerError {
+    fn from(value: SenderError) -> Self {
+        match value {
+            SenderError::StdIoError(_) => Self::ConnectionError,
+        }
+    }
+}
+
+impl From<std::io::Error> for ListenerError {
+    fn from(_: std::io::Error) -> Self {
+        Self::ConnectionError
+    }
+}

src/login.rs

@@ -1,13 +1,12 @@
-use anyhow::Result;
 use tokio::{io::BufWriter, net::TcpStream};
 
-use crate::{ServerInfo, sender::IrcResponseCodes, user::User};
+use crate::{ServerInfo, error_structs::SenderError, sender::IrcResponseCodes, user::User};
 
 pub async fn send_motd(
     server_info: ServerInfo,
     user_info: User,
     writer: &mut BufWriter<TcpStream>,
-) -> Result<()> {
+) -> Result<(), SenderError> {
     let user_info = user_info.unwrap_all();
     let server_version = &format!("IRS-v{}", env!("CARGO_PKG_VERSION")) as &str;
 

src/main.rs

@@ -4,7 +4,7 @@ use std::{
     str::FromStr,
 };
 
-use anyhow::{Result, bail};
+use anyhow::Error as AnyhowError;
 use once_cell::sync::Lazy;
 use tokio::{
     io::{AsyncBufReadExt, BufReader as TokioBufReader, BufWriter as TokioBufWriter},
@@ -19,6 +19,7 @@ use tracing::instrument;
 
 use crate::{
     channels::Channel,
+    error_structs::{HandlerError, ListenerError},
     login::send_motd,
     messages::Message,
     sender::{IrcResponse, IrcResponseCodes},
@@ -27,6 +28,7 @@ use crate::{
 
 mod channels;
 mod commands;
+mod error_structs;
 mod login;
 mod messages;
 mod sender;
@@ -49,7 +51,7 @@ struct ServerInfo {
 }
 
 #[tokio::main]
-async fn main() -> Result<()> {
+async fn main() -> Result<(), AnyhowError> {
     #[cfg(feature = "tokio-console")]
     console_subscriber::init();
 
@@ -83,7 +85,11 @@ async fn main() -> Result<()> {
 }
 
 #[instrument]
-async fn handle_connection(stream: TcpStream, info: ServerInfo, tx: Sender<Message>) -> Result<()> {
+async fn handle_connection(
+    stream: TcpStream,
+    info: ServerInfo,
+    tx: Sender<Message>,
+) -> Result<(), HandlerError> {
     let stream_tcp = stream.try_clone()?;
     let mut message_receiver = tx.clone().subscribe();
     let mut tcp_reader = TokioBufReader::new(TokioTcpStream::from_std(stream.try_clone()?)?);
@@ -106,8 +112,14 @@ async fn handle_connection(stream: TcpStream, info: ServerInfo, tx: Sender<Messa
             result = message_listener(&state, &mut message_receiver, &mut tcp_writer) => {
                 match result {
                     Ok(_) => {},
-                    Err(_) => {
-                        // break;
+                    Err(err) => {
+                        match err {
+                            ListenerError::ConnectionError => {
+                                break;
+                            }
+
+                            _ => {}
+                        };
                     }
                 }
             },
@@ -124,21 +136,21 @@ async fn tcp_listener(
     mut state: User,
     info: &ServerInfo,
     reader: &mut TokioBufReader<TokioTcpStream>,
-) -> Result<User> {
+) -> Result<User, ListenerError> {
     let mut buffer = String::new();
 
     let mut writer = TokioBufWriter::new(TokioTcpStream::from_std(stream.try_clone()?)?);
 
     buffer.clear();
     match reader.read_line(&mut buffer).await {
-        Ok(0) => bail!("invalid response"),
+        Ok(0) => return Err(ListenerError::ConnectionError),
         Ok(_) => {}
 
         Err(_) => {
             let mut conneted_users = CONNECTED_USERS.lock().await;
             let _ = conneted_users.remove(&state.clone().unwrap_all());
 
-            bail!("client disconnected")
+            return Err(ListenerError::ConnectionError);
         }
     }
 
@@ -177,9 +189,9 @@ async fn message_listener(
     user_wrapped: &User,
     receiver: &mut Receiver<Message>,
     writer: &mut TokioBufWriter<TokioTcpStream>,
-) -> Result<()> {
+) -> Result<(), ListenerError> {
     if !user_wrapped.is_populated() {
-        bail!("user has not registered yet, returning...");
+        return Err(ListenerError::UserIsUnidentified);
     }
 
     let user = user_wrapped.clone().unwrap_all();

src/sender.rs

@@ -1,9 +1,10 @@
-use anyhow::Result;
 use tokio::{
     io::{AsyncWriteExt, BufWriter},
     net::TcpStream,
 };
 
+use crate::error_structs::SenderError;
+
 #[derive(Clone)]
 pub struct IrcResponse {
     pub sender: Option<String>,
@@ -32,7 +33,7 @@ impl IrcResponse {
         hostname: &str,
         writer: &mut BufWriter<TcpStream>,
         prepend_column: bool,
-    ) -> Result<()> {
+    ) -> Result<(), SenderError> {
         let sender = format!(":{}", self.sender.clone().unwrap_or(hostname.to_string()));
         let mut full_response = Vec::new();