kotlin-coroutines

name	kotlin-coroutines
description	Kotlin coroutines - structured concurrency, Flows, exception handling
version	1.0.0
sasmp_version	1.3.0
bonded_agent	03-kotlin-coroutines
bond_type	PRIMARY_BOND
execution	{"timeout_ms":30000,"retry":{"max_attempts":3,"backoff":"exponential","initial_delay_ms":1000}}
parameters	{"required":[{"name":"pattern","type":"string","validation":"^(basic|structured|exception|testing)$"}],"optional":[{"name":"dispatcher","type":"string","default":"Default"}]}
logging	{"level":"info","events":["skill_invoked","pattern_loaded","error_occurred"]}

Kotlin Coroutines Skill

Master asynchronous programming with structured concurrency.

Topics Covered

Structured Concurrency

// ✅ Structured - cancellation propagates
class Repository(private val scope: CoroutineScope) {
    suspend fun load() = withContext(Dispatchers.IO) { fetch() }
}

// ❌ Avoid GlobalScope
GlobalScope.launch { /* leaks */ }

Exception Handling

suspend fun loadData() = supervisorScope {
    val a = async { fetchA() }
    val b = async { fetchB() }
    Result(a.awaitOrNull(), b.awaitOrNull())
}

// Never swallow CancellationException
catch (e: Exception) {
    if (e is CancellationException) throw e
}

Testing

@Test
fun test() = runTest {
    val vm = ViewModel(testDispatcher)
    vm.load()
    advanceUntilIdle()
    assertThat(vm.state.value.data).isNotNull()
}

Troubleshooting

Issue	Resolution
Coroutine leak	Use structured scopes, not GlobalScope
Test hangs	Inject TestDispatcher, use advanceUntilIdle()

Usage

Skill("kotlin-coroutines")