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/*
* Copyright 2016-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
*/
package kotlinx.coroutines.flow
import kotlinx.coroutines.*
import kotlinx.coroutines.channels.*
import kotlin.test.*
class FlowOnTest : TestBase() {
@Test
fun testFlowOn() = runTest {
val source = Source(42)
val consumer = Consumer(42)
val flow = source::produce.asFlow()
flow.flowOn(NamedDispatchers("ctx1")).launchIn(this) {
onEach { consumer.consume(it) }
}.join()
assertEquals("ctx1", source.contextName)
assertEquals("main", consumer.contextName)
flow.flowOn(NamedDispatchers("ctx2")).launchIn(this) {
onEach { consumer.consume(it) }
}.join()
assertEquals("ctx2", source.contextName)
assertEquals("main", consumer.contextName)
}
@Test
fun testFlowOnAndOperators() = runTest {
val source = Source(42)
val consumer = Consumer(42)
val captured = ArrayList<String>()
val mapper: suspend (Int) -> Int = {
captured += NamedDispatchers.nameOr("main")
it
}
val flow = source::produce.asFlow()
flow.map(mapper)
.flowOn(NamedDispatchers("ctx1"))
.map(mapper)
.flowOn(NamedDispatchers("ctx2"))
.map(mapper)
.launchIn(this) {
onEach { consumer.consume(it) }
}.join()
assertEquals(listOf("ctx1", "ctx2", "main"), captured)
assertEquals("ctx1", source.contextName)
assertEquals("main", consumer.contextName)
}
@Test
public fun testFlowOnThrowingSource() = runTest {
val flow = flow {
expect(1)
emit(NamedDispatchers.name())
expect(3)
throw TestException()
}.map {
expect(2)
assertEquals("throwing", it)
it
}.flowOn(NamedDispatchers("throwing"))
assertFailsWith<TestException> { flow.single() }
ensureActive()
finish(4)
}
@Test
public fun testFlowOnThrowingOperator() = runTest {
val flow = flow {
expect(1)
emit(NamedDispatchers.name())
expectUnreached()
}.map {
expect(2)
assertEquals("throwing", it)
throw TestException(); it
}.flowOn(NamedDispatchers("throwing"))
assertFailsWith<TestException>(flow)
ensureActive()
finish(3)
}
@Test
public fun testFlowOnDownstreamOperator() = runTest() {
val flow = flow {
expect(2)
emit(NamedDispatchers.name())
hang { expect(5) }
delay(Long.MAX_VALUE)
}.map {
expect(3)
it
}.flowOn(NamedDispatchers("throwing"))
.map<String, String> {
expect(4);
throw TestException()
}
expect(1)
assertFailsWith<TestException> { flow.single() }
ensureActive()
finish(6)
}
@Test
public fun testFlowOnThrowingConsumer() = runTest {
val flow = flow {
expect(2)
emit(NamedDispatchers.name())
hang { expect(4) }
}
expect(1)
flow.flowOn(NamedDispatchers("...")).launchIn(this + NamedDispatchers("launch")) {
onEach {
expect(3)
throw TestException()
}
catch<Throwable> { expect(5) }
}.join()
ensureActive()
finish(6)
}
@Test
fun testFlowOnWithJob() = runTest({ it is IllegalArgumentException }) {
flow {
emit(1)
}.flowOn(NamedDispatchers("foo") + Job())
}
@Test
fun testFlowOnCancellation() = runTest {
val latch = Channel<Unit>()
expect(1)
val job = launch(NamedDispatchers("launch")) {
flow<Int> {
expect(2)
latch.send(Unit)
expect(3)
hang {
assertEquals("cancelled", NamedDispatchers.name())
expect(5)
}
}.flowOn(NamedDispatchers("cancelled")).single()
}
latch.receive()
expect(4)
job.cancel()
job.join()
ensureActive()
finish(6)
}
@Test
fun testFlowOnCancellationHappensBefore() = runTest {
launch {
try {
flow<Int> {
expect(1)
val flowJob = kotlin.coroutines.coroutineContext[Job]!!
launch {
expect(2)
flowJob.cancel()
}
hang { expect(3) }
}.flowOn(NamedDispatchers("upstream")).single()
} catch (e: CancellationException) {
expect(4)
}
}.join()
ensureActive()
finish(5)
}
@Test
fun testIndependentOperatorContext() = runTest {
val value = flow {
assertEquals("base", NamedDispatchers.nameOr("main"))
expect(1)
emit(-239)
}.map {
assertEquals("base", NamedDispatchers.nameOr("main"))
expect(2)
it
}.flowOn(NamedDispatchers("base"))
.map {
assertEquals("main", NamedDispatchers.nameOr("main"))
expect(3)
it
}.single()
assertEquals(-239, value)
finish(4)
}
@Test
fun testMultipleFlowOn() = runTest {
flow {
assertEquals("ctx1", NamedDispatchers.nameOr("main"))
expect(1)
emit(1)
}.map {
assertEquals("ctx1", NamedDispatchers.nameOr("main"))
expect(2)
}.flowOn(NamedDispatchers("ctx1"))
.map {
assertEquals("ctx2", NamedDispatchers.nameOr("main"))
expect(3)
}.flowOn(NamedDispatchers("ctx2"))
.map {
assertEquals("ctx3", NamedDispatchers.nameOr("main"))
expect(4)
}.flowOn(NamedDispatchers("ctx3"))
.map {
assertEquals("main", NamedDispatchers.nameOr("main"))
expect(5)
}
.single()
finish(6)
}
@Test
fun testTimeoutExceptionUpstream() = runTest {
val flow = flow {
emit(1)
yield()
withTimeout(-1) {}
emit(42)
}.flowOn(NamedDispatchers("foo")).onEach {
expect(1)
}
assertFailsWith<TimeoutCancellationException>(flow)
finish(2)
}
@Test
fun testTimeoutExceptionDownstream() = runTest {
val flow = flow {
emit(1)
hang { expect(2) }
}.flowOn(NamedDispatchers("foo")).onEach {
expect(1)
withTimeout(-1) {}
}
assertFailsWith<TimeoutCancellationException>(flow)
finish(3)
}
@Test
fun testCancellation() = runTest {
val result = flow {
emit(1)
emit(2)
emit(3)
expectUnreached()
emit(4)
}.flowOn(wrapperDispatcher())
.buffer(0)
.take(2)
.toList()
assertEquals(listOf(1, 2), result)
}
@Test
fun testException() = runTest {
val flow = flow {
emit(314)
delay(Long.MAX_VALUE)
}.flowOn(NamedDispatchers("upstream"))
.map {
throw TestException()
}
assertFailsWith<TestException> { flow.single() }
assertFailsWith<TestException>(flow)
ensureActive()
}
@Test
fun testIllegalArgumentException() {
val flow = emptyFlow<Int>()
assertFailsWith<IllegalArgumentException> { flow.flowOn(Job()) }
}
private inner class Source(private val value: Int) {
public var contextName: String = "unknown"
fun produce(): Int {
contextName = NamedDispatchers.nameOr("main")
return value
}
}
private inner class Consumer(private val expected: Int) {
public var contextName: String = "unknown"
fun consume(value: Int) {
contextName = NamedDispatchers.nameOr("main")
assertEquals(expected, value)
}
}
}
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