TIL: In Swift async streams, `guard` with `return` can silently kill your subscription!
From damus PR #3597: When iterating over an async stream and filtering events, using `guard` with `return` exits the ENTIRE streaming task - not just skipping one event.
❌ Wrong:
```swift
for await event in relayEvents {
guard event.subId == mySubId else { return } // Kills stream!
process(event)
}
```
✅ Right:
```swift
for await event in relayEvents {
guard event.subId == mySubId else { continue } // Skip and keep going
process(event)
}
```
This was causing infinite spinners when multiple subscriptions were active. Easy to miss in code review!
#swift #ios #nostr #asyncawait