feat: mad not properly surfaces panics

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

crates/mad/src/lib.rs

@@ -77,8 +77,11 @@
 
 use futures::stream::FuturesUnordered;
 use futures_util::StreamExt;
-use std::{fmt::Display, sync::Arc, error::Error};
+use std::{error::Error, fmt::Display, sync::Arc};
-use tokio::signal::unix::{SignalKind, signal};
+use tokio::{
+    signal::unix::{SignalKind, signal},
+    task::JoinError,
+};
 
 use tokio_util::sync::CancellationToken;
 
@@ -101,15 +104,13 @@ pub enum MadError {
 
     /// Error that occurred during the run phase of a component.
     #[error(transparent)]
-    RunError { 
+    RunError { run: anyhow::Error },
-        run: anyhow::Error 
-    },
 
     /// Error that occurred during the close phase of a component.
     #[error("component(s) failed during close")]
     CloseError {
         #[source]
-        close: anyhow::Error 
+        close: anyhow::Error,
     },
 
     /// Multiple errors from different components.
@@ -501,11 +502,32 @@ impl Mad {
 
                 tracing::debug!(component = name, "mad running");
 
+                let handle = tokio::spawn(async move { comp.run(job_cancellation).await });
+
                 tokio::select! {
                     _ = cancellation_token.cancelled() => {
                         error_tx.send(CompletionResult { res: Ok(()) , name  }).await
                     }
-                    res = comp.run(job_cancellation) => {
+                    res = handle => {
+                     let res = match res {
+                         Ok(res) => res,
+                         Err(join) => {
+                             match join.source() {
+                                 Some(error) => {
+                                     Err(MadError::RunError{run: anyhow::anyhow!("component aborted: {:?}", error)})
+                                 },
+                                 None => {
+                                     if join.is_panic(){
+                                         Err(MadError::RunError { run: anyhow::anyhow!("component panicked: {}", join) })
+                                     } else {
+                                         Err(MadError::RunError { run: anyhow::anyhow!("component faced unknown error: {}", join) })
+                                     }
+                                 },
+                             }
+                         },
+                     };
+
+
                         error_tx.send(CompletionResult { res , name  }).await
                     }
                 }
@@ -818,13 +840,13 @@ mod tests {
     fn test_aggregate_error_display() {
         let error1 = MadError::Inner(
             anyhow::anyhow!("database connection failed")
-                .context("failed to connect to PostgreSQL")
+                .context("failed to connect to PostgreSQL"),
         );
 
         let error2 = MadError::Inner(
             anyhow::anyhow!("port already in use")
                 .context("failed to bind to port 8080")
-                .context("web server initialization failed")
+                .context("web server initialization failed"),
         );
 
         let aggregate = MadError::AggregateError(AggregateError {
@@ -864,7 +886,7 @@ mod tests {
         let error = MadError::Inner(
             anyhow::anyhow!("root cause")
                 .context("middle layer")
-                .context("top layer")
+                .context("top layer"),
         );
 
         // Test that we can access the error chain

crates/mad/tests/mod.rs

@@ -138,6 +138,30 @@ async fn test_can_shutdown_gracefully() -> anyhow::Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+#[traced_test]
+async fn test_component_panics_shutdowns_cleanly() -> anyhow::Result<()> {
+    let res = Mad::builder()
+        .add_fn({
+            move |_cancel| async move {
+                panic!("my inner panic");
+            }
+        })
+        .add_fn(|cancel| async move {
+            cancel.cancelled().await;
+
+            Ok(())
+        })
+        .run()
+        .await;
+
+    let err_content = res.unwrap_err().to_string();
+    assert!(err_content.contains("component panicked"));
+    assert!(err_content.contains("my inner panic"));
+
+    Ok(())
+}
+
 #[test]
 fn test_can_easily_transform_error() -> anyhow::Result<()> {
     fn fallible() -> anyhow::Result<()> {