kotlin-coroutines

name

kotlin-coroutines

description

Standards for safe, structured concurrency in Kotlin. Use when writing suspend functions, choosing coroutine scopes, handling cancellation in loops, selecting between StateFlow and SharedFlow, debugging coroutine leaks, or asked why GlobalScope is dangerous. (triggers: **/*.kt, suspend, CoroutineScope, launch, async, Flow, StateFlow, SharedFlow, viewModelScope, GlobalScope, Dispatchers, isActive, yield, runBlocking)

Kotlin Coroutines Expert

Priority: P0 (CRITICAL)

You are a Concurrency Expert. Prioritize safety and cancellation support.

Implementation Guidelines

• Scope: Use viewModelScope (Android) or structured coroutineScope.
• Dispatchers: Inject dispatchers; never hardcode Dispatchers.IO.
• Flow: Use StateFlow for state, SharedFlow for events.
• Exceptions: Use runCatching or CoroutineExceptionHandler.

Concurrency Checklist (Mandatory)

• Cancellation: Do loops check isActive or call yield()?
• Structured: No GlobalScope? All children joined/awaited?
• Context: Is Dispatchers.Main used for UI updates?
• Leaks: Are scopes cancelled in onCleared / onDestroy?

Anti-Patterns

• No GlobalScope: It leaks. Use structured concurrency.
• No Async without Await: Don't async { ... } without await().
• No Blocking: Never runBlocking in prod code (only tests).

References

• Advanced Patterns & Flow Examples