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fix(NATSRS-002): CU-86akbhg13 publish() unwrap() panics on send failure instead of propagating an error #103

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fix(NATSRS-002): CU-86akbhg13 publish() unwrap() panics on send failure instead of propagating an error #103

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9 changes: 7 additions & 2 deletions async-nats/src/jetstream/consumer/push.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -153,10 +153,15 @@ impl futures_util::Stream for Messages {
// TODO store pending_publish as a future and return errors from it
let client = self.context.client.clone();
tokio::task::spawn(async move {
client
if let Err(err) = client
.publish(subject, Bytes::from_static(b""))
.await

@flamingo flamingo Bot Aug 24, 2026

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🦩 🟠 publish() unwrap() panics on send failure instead of propagating an error

In impl futures_util::Stream for Messages::poll_next (push.rs), replaced the client.publish(subject, Bytes::from_static(b"")).await.unwrap() call inside the spawned heartbeat-response task with an if let Err(err) = ... { tracing::warn!(...) } pattern, matching the suggested fix exactly. This prevents a panic in the detached tokio task on publish failure and instead logs the error via tracing::warn!, consistent with the sibling Ordered::poll_next heartbeat handler which already used .ok() to swallow errors non-fatally. Note: the error is still not propagated through MessagesError/the Stream's Item type (as the finding's title suggests would be ideal), since doing so would require restructuring the poll loop to track a pending publish future — this minimal fix satisfies the concrete suggested fix and eliminates the panic risk, but full error propagation to the stream consumer is not implemented.

🤖 Prompt for AI agents 
In async-nats/src/jetstream/consumer/push.rs around line 158, review and complete this code-review fix: publish() unwrap() panics on send failure instead of propagating an error.
What the draft fix changed: In `impl futures_util::Stream for Messages::poll_next` (push.rs), replaced the `client.publish(subject, Bytes::from_static(b"")).await.unwrap()` call inside the spawned heartbeat-response task with an `if let Err(err) = ... { tracing::warn!(...) }` pattern, matching the suggested fix exactly. This prevents a panic in the detached tokio task on publish failure and instead logs the error via `tracing::warn!`, consistent with the sibling `Ordered::poll_next` heartbeat handler which already used `.ok()` to swallow errors non-fatally. Note: the error is still not propagated through `MessagesError`/the Stream's `Item` type (as the finding's title suggests would be ideal), since doing so would require restructuring the poll loop to track a pending publish future — this minimal fix satisfies the concrete suggested fix and eliminates the panic risk, but full error propagation to the stream consumer is not implemented.
Verify the change is correct and complete; do not refactor unrelated code.

fix confidence: 🟢 90 high — react 👍/👎 to teach the reviewer

.unwrap();
{
tracing::warn!(
"failed to respond to idle heartbeat: {}",
err
);
}
});
}

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