feat: replace async-trait with erased box type

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/mad/Cargo.toml

@@ -10,7 +10,6 @@ readme = "../../README.md"
 
 [dependencies]
 anyhow.workspace = true
-async-trait = "0.1.81"
 futures = "0.3.30"
 futures-util = "0.3.30"
 rand = "0.9.0"

crates/mad/examples/basic/main.rs

@@ -1,16 +1,14 @@
-use async_trait::async_trait;
 use rand::Rng;
 use tokio_util::sync::CancellationToken;
 use tracing::Level;
 
 struct WaitServer {}
-#[async_trait]
 impl notmad::Component for WaitServer {
     fn name(&self) -> Option<String> {
         Some("WaitServer".into())
     }
 
-    async fn run(&self, cancellation: CancellationToken) -> Result<(), notmad::MadError> {
+    async fn run(&self, _cancellation: CancellationToken) -> Result<(), notmad::MadError> {
         let millis_wait = rand::thread_rng().gen_range(500..3000);
 
         tracing::debug!("waiting: {}ms", millis_wait);

crates/mad/examples/comprehensive/main.rs

@@ -7,7 +7,6 @@
 //! - Graceful shutdown with cancellation tokens
 //! - Concurrent component execution
 
-use async_trait::async_trait;
 use notmad::{Component, Mad, MadError};
 use std::sync::Arc;
 use std::sync::atomic::{AtomicUsize, Ordering};
@@ -21,7 +20,6 @@ struct WebServer {
     request_count: Arc<AtomicUsize>,
 }
 
-#[async_trait]
 impl Component for WebServer {
     fn name(&self) -> Option<String> {
         Some(format!("web-server-{}", self.port))
@@ -81,7 +79,6 @@ struct JobProcessor {
     processing_interval: Duration,
 }
 
-#[async_trait]
 impl Component for JobProcessor {
     fn name(&self) -> Option<String> {
         Some(format!("job-processor-{}", self.queue_name))
@@ -139,7 +136,6 @@ struct HealthChecker {
     check_interval: Duration,
 }
 
-#[async_trait]
 impl Component for HealthChecker {
     fn name(&self) -> Option<String> {
         Some("health-checker".to_string())
@@ -181,7 +177,6 @@ struct FailingComponent {
     fail_after: Duration,
 }
 
-#[async_trait]
 impl Component for FailingComponent {
     fn name(&self) -> Option<String> {
         Some("failing-component".to_string())
@@ -209,7 +204,6 @@ impl Component for FailingComponent {
 /// Debug component that logs system status periodically.
 struct DebugComponent;
 
-#[async_trait]
 impl Component for DebugComponent {
     fn name(&self) -> Option<String> {
         Some("debug-component".to_string())

crates/mad/examples/error_log/main.rs

@@ -1,16 +1,14 @@
-use async_trait::async_trait;
 use rand::Rng;
 use tokio_util::sync::CancellationToken;
 use tracing::Level;
 
 struct ErrorServer {}
-#[async_trait]
 impl notmad::Component for ErrorServer {
     fn name(&self) -> Option<String> {
         Some("ErrorServer".into())
     }
 
-    async fn run(&self, cancellation: CancellationToken) -> Result<(), notmad::MadError> {
+    async fn run(&self, _cancellation: CancellationToken) -> Result<(), notmad::MadError> {
         let millis_wait = rand::thread_rng().gen_range(500..3000);
 
         tracing::debug!("waiting: {}ms", millis_wait);

crates/mad/examples/fn/main.rs

@@ -1,10 +1,8 @@
-use async_trait::async_trait;
 use rand::Rng;
 use tokio_util::sync::CancellationToken;
 use tracing::Level;
 
 struct WaitServer {}
-#[async_trait]
 impl notmad::Component for WaitServer {
     fn name(&self) -> Option<String> {
         Some("WaitServer".into())

crates/mad/examples/multi_service/main.rs

@@ -3,7 +3,6 @@
 //! This example shows how to run a web server, queue processor, and
 //! scheduled task together, with graceful shutdown on Ctrl+C.
 
-use async_trait::async_trait;
 use notmad::{Component, Mad, MadError};
 use tokio::time::{Duration, interval};
 use tokio_util::sync::CancellationToken;
@@ -16,7 +15,6 @@ struct WebServer {
     port: u16,
 }
 
-#[async_trait]
 impl Component for WebServer {
     fn name(&self) -> Option<String> {
         Some(format!("WebServer:{}", self.port))
@@ -70,7 +68,6 @@ struct QueueProcessor {
     queue_name: String,
 }
 
-#[async_trait]
 impl Component for QueueProcessor {
     fn name(&self) -> Option<String> {
         Some(format!("QueueProcessor:{}", self.queue_name))
@@ -116,7 +113,6 @@ struct ScheduledTask {
     interval_secs: u64,
 }
 
-#[async_trait]
 impl Component for ScheduledTask {
     fn name(&self) -> Option<String> {
         Some(format!("ScheduledTask:{}", self.task_name))

crates/mad/examples/nested_errors/main.rs

@@ -1,11 +1,9 @@
-use async_trait::async_trait;
 use tokio_util::sync::CancellationToken;
 
 struct NestedErrorComponent {
     name: String,
 }
 
-#[async_trait]
 impl notmad::Component for NestedErrorComponent {
     fn name(&self) -> Option<String> {
         Some(self.name.clone())
@@ -28,7 +26,6 @@ impl notmad::Component for NestedErrorComponent {
 
 struct AnotherFailingComponent;
 
-#[async_trait]
 impl notmad::Component for AnotherFailingComponent {
     fn name(&self) -> Option<String> {
         Some("another-component".into())

crates/mad/examples/signals/main.rs

@@ -1,16 +1,14 @@
-use async_trait::async_trait;
 use rand::Rng;
 use tokio_util::sync::CancellationToken;
 use tracing::Level;
 
 struct WaitServer {}
-#[async_trait]
 impl notmad::Component for WaitServer {
     fn name(&self) -> Option<String> {
         Some("WaitServer".into())
     }
 
-    async fn run(&self, cancellation: CancellationToken) -> Result<(), notmad::MadError> {
+    async fn run(&self, _cancellation: CancellationToken) -> Result<(), notmad::MadError> {
         let millis_wait = rand::thread_rng().gen_range(500..3000);
 
         tracing::debug!("waiting: {}ms", millis_wait);
@@ -23,7 +21,6 @@ impl notmad::Component for WaitServer {
 }
 
 struct RespectCancel {}
-#[async_trait]
 impl notmad::Component for RespectCancel {
     fn name(&self) -> Option<String> {
         Some("RespectCancel".into())
@@ -38,13 +35,12 @@ impl notmad::Component for RespectCancel {
 }
 
 struct NeverStopServer {}
-#[async_trait]
 impl notmad::Component for NeverStopServer {
     fn name(&self) -> Option<String> {
         Some("NeverStopServer".into())
     }
 
-    async fn run(&self, cancellation: CancellationToken) -> Result<(), notmad::MadError> {
+    async fn run(&self, _cancellation: CancellationToken) -> Result<(), notmad::MadError> {
         // Simulates a server running for some time. Is normally supposed to be futures blocking indefinitely
         tokio::time::sleep(std::time::Duration::from_millis(999999999)).await;
 

crates/mad/src/lib.rs

@@ -77,11 +77,8 @@
 
 use futures::stream::FuturesUnordered;
 use futures_util::StreamExt;
-use std::{error::Error, fmt::Display, sync::Arc};
-use tokio::{
-    signal::unix::{SignalKind, signal},
-    task::JoinError,
-};
+use std::{error::Error, fmt::Display, pin::Pin, sync::Arc};
+use tokio::signal::unix::{SignalKind, signal};
 
 use tokio_util::sync::CancellationToken;
 
@@ -229,7 +226,7 @@ impl Display for AggregateError {
 /// # }
 /// ```
 pub struct Mad {
-    components: Vec<Arc<dyn Component + Send + Sync + 'static>>,
+    components: Vec<SharedComponent>,
 
     should_cancel: Option<std::time::Duration>,
 }
@@ -397,7 +394,7 @@ impl Mad {
     /// # Arguments
     ///
     /// * `should_cancel` - Duration to wait after cancellation before forcing shutdown.
-    ///                     Pass `None` to wait indefinitely.
+    ///   Pass `None` to wait indefinitely.
     ///
     /// # Example
     ///
@@ -669,8 +666,7 @@ async fn signal_unix_terminate() {
 ///     }
 /// }
 /// ```
-#[async_trait::async_trait]
-pub trait Component {
+pub trait Component: Send + Sync + 'static {
     /// Returns an optional name for the component.
     ///
     /// This name is used in logging and error messages to identify
@@ -698,8 +694,8 @@ pub trait Component {
     ///
     /// If setup fails with an error other than `SetupNotDefined`,
     /// the entire application will stop before any components start running.
-    async fn setup(&self) -> Result<(), MadError> {
-        Err(MadError::SetupNotDefined)
+    fn setup(&self) -> impl Future<Output = Result<(), MadError>> + Send + '_ {
+        async { Err(MadError::SetupNotDefined) }
     }
 
     /// Main execution phase of the component.
@@ -721,7 +717,10 @@ pub trait Component {
     /// # Errors
     ///
     /// Any error returned will trigger shutdown of all other components.
-    async fn run(&self, cancellation_token: CancellationToken) -> Result<(), MadError>;
+    fn run(
+        &self,
+        cancellation_token: CancellationToken,
+    ) -> impl Future<Output = Result<(), MadError>> + Send + '_;
 
     /// Optional cleanup phase called after the component stops.
     ///
@@ -738,8 +737,73 @@ pub trait Component {
     ///
     /// Errors during close are logged but don't prevent other components
     /// from closing.
+    fn close(&self) -> impl Future<Output = Result<(), MadError>> + Send + '_ {
+        async { Err(MadError::CloseNotDefined) }
+    }
+}
+
+trait AsyncComponent: Send + Sync + 'static {
+    fn name_async(&self) -> Option<String>;
+
+    fn setup_async(&self) -> Pin<Box<dyn Future<Output = Result<(), MadError>> + Send + '_>>;
+
+    fn run_async(
+        &self,
+        cancellation_token: CancellationToken,
+    ) -> Pin<Box<dyn Future<Output = Result<(), MadError>> + Send + '_>>;
+
+    fn close_async(&self) -> Pin<Box<dyn Future<Output = Result<(), MadError>> + Send + '_>>;
+}
+
+impl<E: Component> AsyncComponent for E {
+    #[inline(always)]
+    fn name_async(&self) -> Option<String> {
+        self.name()
+    }
+
+    #[inline(always)]
+    fn setup_async(&self) -> Pin<Box<dyn Future<Output = Result<(), MadError>> + Send + '_>> {
+        Box::pin(self.setup())
+    }
+
+    #[inline(always)]
+    fn run_async(
+        &self,
+        cancellation_token: CancellationToken,
+    ) -> Pin<Box<dyn Future<Output = Result<(), MadError>> + Send + '_>> {
+        Box::pin(self.run(cancellation_token))
+    }
+
+    #[inline(always)]
+    fn close_async(&self) -> Pin<Box<dyn Future<Output = Result<(), MadError>> + Send + '_>> {
+        Box::pin(self.close())
+    }
+}
+
+#[derive(Clone)]
+pub struct SharedComponent {
+    component: Arc<dyn AsyncComponent + Send + Sync + 'static>,
+}
+
+impl SharedComponent {
+    #[inline(always)]
+    pub fn name(&self) -> Option<String> {
+        self.component.name_async()
+    }
+
+    #[inline(always)]
+    async fn setup(&self) -> Result<(), MadError> {
+        self.component.setup_async().await
+    }
+
+    #[inline(always)]
+    async fn run(&self, cancellation_token: CancellationToken) -> Result<(), MadError> {
+        self.component.run_async(cancellation_token).await
+    }
+
+    #[inline(always)]
     async fn close(&self) -> Result<(), MadError> {
-        Err(MadError::CloseNotDefined)
+        self.component.close_async().await
     }
 }
 
@@ -769,12 +833,14 @@ pub trait Component {
 /// ```
 pub trait IntoComponent {
     /// Converts self into an Arc-wrapped component.
-    fn into_component(self) -> Arc<dyn Component + Send + Sync + 'static>;
+    fn into_component(self) -> SharedComponent;
 }
 
-impl<T: Component + Send + Sync + 'static> IntoComponent for T {
-    fn into_component(self) -> Arc<dyn Component + Send + Sync + 'static> {
-        Arc::new(self)
+impl<T: Component> IntoComponent for T {
+    fn into_component(self) -> SharedComponent {
+        SharedComponent {
+            component: Arc::new(self),
+        }
     }
 }
 
@@ -798,7 +864,6 @@ where
     }
 }
 
-#[async_trait::async_trait]
 impl<F, Fut> Component for ClosureComponent<F, Fut>
 where
     F: Fn(CancellationToken) -> Fut + Send + Sync + 'static,
@@ -812,7 +877,6 @@ where
 #[cfg(test)]
 mod tests {
     use super::*;
-    use anyhow::Context;
 
     #[test]
     fn test_error_chaining_display() {
@@ -909,7 +973,6 @@ mod tests {
     async fn test_component_error_propagation() {
         struct FailingComponent;
 
-        #[async_trait::async_trait]
         impl Component for FailingComponent {
             fn name(&self) -> Option<String> {
                 Some("test-component".to_string())

crates/mad/src/waiter.rs

@@ -4,19 +4,15 @@
 //! without performing any work. Useful for keeping the application alive
 //! or as placeholders in conditional component loading.
 
-use std::sync::Arc;
-
-use async_trait::async_trait;
 use tokio_util::sync::CancellationToken;
 
-use crate::{Component, MadError};
+use crate::{Component, IntoComponent, MadError, SharedComponent};
 
 /// A default waiter component that panics if run.
 ///
 /// This is used internally as a placeholder that should never
 /// actually be executed.
-pub struct DefaultWaiter {}
-#[async_trait]
+pub struct DefaultWaiter;
 impl Component for DefaultWaiter {
     async fn run(&self, _cancellation_token: CancellationToken) -> Result<(), MadError> {
         panic!("should never be called");
@@ -38,13 +34,13 @@ impl Component for DefaultWaiter {
 /// let waiter = Waiter::new(service.into_component());
 /// ```
 pub struct Waiter {
-    comp: Arc<dyn Component + Send + Sync + 'static>,
+    comp: SharedComponent,
 }
 
 impl Default for Waiter {
     fn default() -> Self {
         Self {
-            comp: Arc::new(DefaultWaiter {}),
+            comp: DefaultWaiter {}.into_component(),
         }
     }
 }
@@ -54,12 +50,11 @@ impl Waiter {
     ///
     /// The wrapped component's name will be used (prefixed with "waiter/"),
     /// but its run method will not be called.
-    pub fn new(c: Arc<dyn Component + Send + Sync + 'static>) -> Self {
+    pub fn new(c: SharedComponent) -> Self {
         Self { comp: c }
     }
 }
 
-#[async_trait]
 impl Component for Waiter {
     /// Returns the name of the waiter, prefixed with "waiter/".
     ///

crates/mad/tests/mod.rs

@@ -1,6 +1,5 @@
 use std::sync::Arc;
 
-use async_trait::async_trait;
 use notmad::{Component, Mad, MadError};
 use rand::Rng;
 use tokio::sync::Mutex;
@@ -9,13 +8,12 @@ use tracing_test::traced_test;
 
 struct NeverEndingRun {}
 
-#[async_trait]
 impl Component for NeverEndingRun {
     fn name(&self) -> Option<String> {
         Some("NeverEndingRun".into())
     }
 
-    async fn run(&self, cancellation: CancellationToken) -> Result<(), notmad::MadError> {
+    async fn run(&self, _cancellation: CancellationToken) -> Result<(), notmad::MadError> {
         let millis_wait = rand::thread_rng().gen_range(50..1000);
 
         tokio::time::sleep(std::time::Duration::from_millis(millis_wait)).await;