improve error handling in update stream (vercel/turborepo#4705)

### Description

Handle fatal errors in update stream, by sending an not found update
with issues.

---------

Co-authored-by: Alex Kirszenberg <alex.kirszenberg@vercel.com>

Author: sokra

crates/turbopack-dev-server/src/http.rs

@@ -42,30 +42,27 @@ enum GetFromSourceResult {
 async fn get_from_source(
     source: ContentSourceVc,
     request: TransientInstance<SourceRequest>,
-    issue_repoter: IssueReporterVc,
 ) -> Result<GetFromSourceResultVc> {
-    Ok(
-        match &*resolve_source_request(source, request, issue_repoter).await? {
-            ResolveSourceRequestResult::Static(static_content_vc, header_overwrites) => {
-                let static_content = static_content_vc.await?;
-                if let AssetContent::File(file) = &*static_content.content.content().await? {
-                    GetFromSourceResult::Static {
-                        content: file.await?,
-                        status_code: static_content.status_code,
-                        headers: static_content.headers.await?,
-                        header_overwrites: header_overwrites.await?,
-                    }
-                } else {
-                    GetFromSourceResult::NotFound
+    Ok(match &*resolve_source_request(source, request).await? {
+        ResolveSourceRequestResult::Static(static_content_vc, header_overwrites) => {
+            let static_content = static_content_vc.await?;
+            if let AssetContent::File(file) = &*static_content.content.content().await? {
+                GetFromSourceResult::Static {
+                    content: file.await?,
+                    status_code: static_content.status_code,
+                    headers: static_content.headers.await?,
+                    header_overwrites: header_overwrites.await?,
                 }
+            } else {
+                GetFromSourceResult::NotFound
             }
-            ResolveSourceRequestResult::HttpProxy(proxy) => {
-                GetFromSourceResult::HttpProxy(proxy.await?)
-            }
-            ResolveSourceRequestResult::NotFound => GetFromSourceResult::NotFound,
         }
-        .cell(),
-    )
+        ResolveSourceRequestResult::HttpProxy(proxy) => {
+            GetFromSourceResult::HttpProxy(proxy.await?)
+        }
+        ResolveSourceRequestResult::NotFound => GetFromSourceResult::NotFound,
+    }
+    .cell())
 }
 
 /// Processes an HTTP request within a given content source and returns the
@@ -77,7 +74,7 @@ pub async fn process_request_with_content_source(
 ) -> Result<Response<hyper::Body>> {
     let original_path = request.uri().path().to_string();
     let request = http_request_to_source_request(request).await?;
-    let result = get_from_source(source, TransientInstance::new(request), issue_reporter);
+    let result = get_from_source(source, TransientInstance::new(request));
     handle_issues(result, &original_path, "get_from_source", issue_reporter).await?;
     match &*result.strongly_consistent().await? {
         GetFromSourceResult::Static {

crates/turbopack-dev-server/src/source/resolve.rs

@@ -6,7 +6,6 @@ use std::{
 use anyhow::{bail, Result};
 use hyper::Uri;
 use turbo_tasks::{TransientInstance, Value};
-use turbopack_core::issue::IssueReporterVc;
 
 use super::{
     headers::{HeaderValue, Headers},
@@ -15,10 +14,7 @@ use super::{
     ContentSourceContent, ContentSourceDataVary, ContentSourceResult, ContentSourceVc,
     HeaderListVc, ProxyResultVc, StaticContentVc,
 };
-use crate::{
-    handle_issues,
-    source::{ContentSource, ContentSourceData, GetContentSourceContent},
-};
+use crate::source::{ContentSource, ContentSourceData, GetContentSourceContent};
 
 /// The result of [`resolve_source_request`]. Similar to a
 /// `ContentSourceContent`, but without the `Rewrite` variant as this is taken
@@ -36,7 +32,6 @@ pub enum ResolveSourceRequestResult {
 pub async fn resolve_source_request(
     source: ContentSourceVc,
     request: TransientInstance<SourceRequest>,
-    issue_reporter: IssueReporterVc,
 ) -> Result<ResolveSourceRequestResultVc> {
     let mut data = ContentSourceData::default();
     let mut current_source = source;
@@ -47,14 +42,6 @@ pub async fn resolve_source_request(
     let mut response_header_overwrites = Vec::new();
     loop {
         let result = current_source.get(&current_asset_path, Value::new(data));
-        handle_issues(
-            result,
-            &original_path,
-            "get content from source",
-            issue_reporter,
-        )
-        .await?;
-
         match &*result.strongly_consistent().await? {
             ContentSourceResult::NotFound => break Ok(ResolveSourceRequestResult::NotFound.cell()),
             ContentSourceResult::NeedData(needed) => {

crates/turbopack-dev-server/src/update/server.rs

@@ -67,12 +67,11 @@ impl<P: SourceProvider + Clone + Send + Sync> UpdateServer<P> {
                                     let source = source_provider.get_source();
                                     resolve_source_request(
                                         source,
-                                        TransientInstance::new(request),
-                                        self.issue_reporter
+                                        TransientInstance::new(request)
                                     )
                                 }
                             };
-                            match UpdateStream::new(TransientInstance::new(Box::new(get_content))).await {
+                            match UpdateStream::new(resource.to_string(), TransientInstance::new(Box::new(get_content))).await {
                                 Ok(stream) => {
                                     streams.insert(resource, stream);
                                 }
@@ -94,7 +93,14 @@ impl<P: SourceProvider + Clone + Send + Sync> UpdateServer<P> {
                     }
                 }
                 Some((resource, update)) = streams.next() => {
-                    Self::send_update(&mut client, &mut streams, resource, &update).await?;
+                    match update {
+                        Ok(update) => {
+                            Self::send_update(&mut client, &mut streams, resource, &update).await?;
+                        }
+                        Err(err) => {
+                            eprintln!("Failed to get update for {resource}: {}", PrettyPrintError(&err));
+                        }
+                    }
                 }
                 else => break
             }

crates/turbopack-dev-server/src/update/stream.rs

@@ -1,12 +1,20 @@
 use std::pin::Pin;
 
-use anyhow::{bail, Result};
+use anyhow::Result;
 use futures::{prelude::*, Stream};
 use tokio::sync::mpsc::Sender;
 use tokio_stream::wrappers::ReceiverStream;
-use turbo_tasks::{CollectiblesSource, IntoTraitRef, State, TraitRef, TransientInstance};
+use turbo_tasks::{
+    primitives::StringVc, CollectiblesSource, IntoTraitRef, State, TraitRef, TransientInstance,
+};
+use turbo_tasks_fs::{FileSystem, FileSystemPathVc};
 use turbopack_core::{
-    issue::{IssueVc, PlainIssueReadRef},
+    error::PrettyPrintError,
+    issue::{
+        Issue, IssueSeverity, IssueSeverityVc, IssueVc, OptionIssueProcessingPathItemsVc,
+        PlainIssueReadRef,
+    },
+    server_fs::ServerFileSystemVc,
     version::{
         NotFoundVersionVc, PartialUpdate, TotalUpdate, Update, UpdateReadRef, VersionVc,
         VersionedContent,
@@ -38,12 +46,43 @@ fn extend_issues(issues: &mut Vec<PlainIssueReadRef>, new_issues: Vec<PlainIssue
 
 #[turbo_tasks::function]
 async fn get_update_stream_item(
+    resource: &str,
     from: VersionStateVc,
     get_content: TransientInstance<GetContentFn>,
 ) -> Result<UpdateStreamItemVc> {
     let content = get_content();
+    let mut plain_issues = peek_issues(content).await?;
+
+    let content_value = match content.await {
+        Ok(content) => content,
+        Err(e) => {
+            plain_issues.push(
+                FatalStreamIssue {
+                    resource: resource.to_string(),
+                    description: StringVc::cell(format!("{}", PrettyPrintError(&e))),
+                }
+                .cell()
+                .as_issue()
+                .into_plain(OptionIssueProcessingPathItemsVc::none())
+                .await?,
+            );
+
+            let update = Update::Total(TotalUpdate {
+                to: NotFoundVersionVc::new()
+                    .as_version()
+                    .into_trait_ref()
+                    .await?,
+            })
+            .cell();
+            return Ok(UpdateStreamItem::Found {
+                update: update.await?,
+                issues: plain_issues,
+            }
+            .cell());
+        }
+    };
 
-    match *content.await? {
+    match *content_value {
         ResolveSourceRequestResult::Static(static_content_vc, _) => {
             let static_content = static_content_vc.await?;
 
@@ -56,8 +95,7 @@ async fn get_update_stream_item(
             let from = from.get();
             let update = resolved_content.update(from);
 
-            let mut plain_issues = peek_issues(update).await?;
-            extend_issues(&mut plain_issues, peek_issues(content).await?);
+            extend_issues(&mut plain_issues, peek_issues(update).await?);
 
             let update = update.await?;
 
@@ -74,7 +112,7 @@ async fn get_update_stream_item(
                 return Ok(UpdateStreamItem::NotFound.cell());
             }
 
-            let plain_issues = peek_issues(proxy_result).await?;
+            extend_issues(&mut plain_issues, peek_issues(proxy_result).await?);
 
             let from = from.get();
             if let Some(from) = ProxyResultVc::resolve_from(from).await? {
@@ -98,8 +136,6 @@ async fn get_update_stream_item(
             .cell())
         }
         _ => {
-            let plain_issues = peek_issues(content).await?;
-
             let update = if plain_issues.is_empty() {
                 // Client requested a non-existing asset
                 // It might be removed in meantime, reload client
@@ -127,19 +163,17 @@ async fn get_update_stream_item(
 
 #[turbo_tasks::function]
 async fn compute_update_stream(
+    resource: &str,
     from: VersionStateVc,
     get_content: TransientInstance<GetContentFn>,
-    sender: TransientInstance<Sender<UpdateStreamItemReadRef>>,
-) -> Result<()> {
-    let item = get_update_stream_item(from, get_content)
+    sender: TransientInstance<Sender<Result<UpdateStreamItemReadRef>>>,
+) {
+    let item = get_update_stream_item(resource, from, get_content)
         .strongly_consistent()
-        .await?;
-
-    if sender.send(item).await.is_err() {
-        bail!("channel closed");
-    }
+        .await;
 
-    Ok(())
+    // Send update. Ignore channel closed error.
+    let _ = sender.send(item).await;
 }
 
 #[turbo_tasks::value]
@@ -172,10 +206,15 @@ impl VersionStateVc {
     }
 }
 
-pub(super) struct UpdateStream(Pin<Box<dyn Stream<Item = UpdateStreamItemReadRef> + Send + Sync>>);
+pub(super) struct UpdateStream(
+    Pin<Box<dyn Stream<Item = Result<UpdateStreamItemReadRef>> + Send + Sync>>,
+);
 
 impl UpdateStream {
-    pub async fn new(get_content: TransientInstance<GetContentFn>) -> Result<UpdateStream> {
+    pub async fn new(
+        resource: String,
+        get_content: TransientInstance<GetContentFn>,
+    ) -> Result<UpdateStream> {
         let (sx, rx) = tokio::sync::mpsc::channel(32);
 
         let content = get_content();
@@ -190,13 +229,18 @@ impl UpdateStream {
         };
         let version_state = VersionStateVc::new(version.into_trait_ref().await?).await?;
 
-        compute_update_stream(version_state, get_content, TransientInstance::new(sx));
+        compute_update_stream(
+            &resource,
+            version_state,
+            get_content,
+            TransientInstance::new(sx),
+        );
 
         let mut last_had_issues = false;
 
         let stream = ReceiverStream::new(rx).filter_map(move |item| {
             let (has_issues, issues_changed) =
-                if let UpdateStreamItem::Found { issues, .. } = &*item {
+                if let Some(UpdateStreamItem::Found { issues, .. }) = item.as_deref().ok() {
                     let has_issues = !issues.is_empty();
                     let issues_changed = has_issues != last_had_issues;
                     last_had_issues = has_issues;
@@ -206,12 +250,8 @@ impl UpdateStream {
                 };
 
             async move {
-                match &*item {
-                    UpdateStreamItem::NotFound => {
-                        // Propagate not found updates so we can drop this update stream.
-                        Some(item)
-                    }
-                    UpdateStreamItem::Found { update, .. } => {
+                match item.as_deref() {
+                    Ok(UpdateStreamItem::Found { update, .. }) => {
                         match &**update {
                             Update::Partial(PartialUpdate { to, .. })
                             | Update::Total(TotalUpdate { to }) => {
@@ -232,6 +272,10 @@ impl UpdateStream {
                             }
                         }
                     }
+                    _ => {
+                        // Propagate other updates
+                        Some(item)
+                    }
                 }
             }
         });
@@ -241,7 +285,7 @@ impl UpdateStream {
 }
 
 impl Stream for UpdateStream {
-    type Item = UpdateStreamItemReadRef;
+    type Item = Result<UpdateStreamItemReadRef>;
 
     fn poll_next(
         self: Pin<&mut Self>,
@@ -260,3 +304,37 @@ pub enum UpdateStreamItem {
         issues: Vec<PlainIssueReadRef>,
     },
 }
+
+#[turbo_tasks::value(serialization = "none")]
+struct FatalStreamIssue {
+    description: StringVc,
+    resource: String,
+}
+
+#[turbo_tasks::value_impl]
+impl Issue for FatalStreamIssue {
+    #[turbo_tasks::function]
+    fn severity(&self) -> IssueSeverityVc {
+        IssueSeverity::Fatal.into()
+    }
+
+    #[turbo_tasks::function]
+    fn context(&self) -> FileSystemPathVc {
+        ServerFileSystemVc::new().root().join(&self.resource)
+    }
+
+    #[turbo_tasks::function]
+    fn category(&self) -> StringVc {
+        StringVc::cell("websocket".to_string())
+    }
+
+    #[turbo_tasks::function]
+    fn title(&self) -> StringVc {
+        StringVc::cell("Fatal error while getting content to stream".to_string())
+    }
+
+    #[turbo_tasks::function]
+    fn description(&self) -> StringVc {
+        self.description
+    }
+}