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Fix nested coroutines binding issue #133

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Fix nested coroutines binding issue #133

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e84a6d0
Fix nested coroutines binding issue
dbottillo Oct 7, 2025
c1538a6
Add nested coroutines binding test
dbottillo Oct 8, 2025
cf46eed
small fix
dbottillo Oct 8, 2025
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2 changes: 1 addition & 1 deletion ...utines/src/commonMain/kotlin/com/github/michaelbull/result/coroutines/CoroutineBinding.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -56,7 +56,7 @@ public suspend inline fun <V, E> coroutineBinding(crossinline block: suspend Cor
}
}
} catch (ex: BindCancellationException) {
receiver.result!!
receiver.result ?: throw ex
}
}

Expand Down
124 changes: 124 additions & 0 deletions ...c/commonTest/kotlin/com/github/michaelbull/result/coroutines/AsyncCoroutineBindingTest.kt
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Expand Up @@ -164,4 +164,128 @@ class AsyncCoroutineBindingTest {
assertTrue(yStateChange)
assertFalse(zStateChange)
}

@Test
fun shouldHandleNestedBindings() = runTest {
var xStateChange = false
var yStateChange = false
var zStateChange = false

suspend fun provideX(): Result<Int, BindingError> {
delay(1)
xStateChange = true
return Ok(1)
}

suspend fun provideXWrapped() = coroutineBinding {
provideX().bind()
}

suspend fun provideY(): Result<Int, BindingError.BindingErrorA> {
delay(20)
yStateChange = true
return Ok(1)
}

suspend fun provideYWrapped() = coroutineBinding {
provideY().bind()
}

suspend fun provideZ(): Result<Int, BindingError.BindingErrorB> {
delay(100)
zStateChange = true
return Ok(1)
}

suspend fun provideZWrapped() = coroutineBinding {
provideZ().bind()
}

val dispatcherA = StandardTestDispatcher(testScheduler)
val dispatcherB = StandardTestDispatcher(testScheduler)
val dispatcherC = StandardTestDispatcher(testScheduler)

val result: Result<Int, BindingError> = coroutineBinding {
val x = async(dispatcherA) { provideXWrapped().bind() }
val y = async(dispatcherB) { provideYWrapped().bind() }

testScheduler.advanceTimeBy(2)
testScheduler.runCurrent()

val z = async(dispatcherC) { provideZWrapped().bind() }

x.await() + y.await() + z.await()
}

assertEquals(
expected = Ok(3),
actual = result
)

assertTrue(xStateChange)
assertTrue(yStateChange)
assertTrue(zStateChange)
}

@Test
fun shouldHandleExceptionsWithNestedBindings() = runTest {
var xStateChange = false
var yStateChange = false
var zStateChange = false

suspend fun provideX(): Result<Int, BindingError> {
delay(1)
xStateChange = true
return Ok(1)
}

suspend fun provideXWrapped() = coroutineBinding {
provideX().bind()
}

suspend fun provideY(): Result<Int, BindingError.BindingErrorA> {
delay(20)
yStateChange = true
return Err(BindingError.BindingErrorA)
}

suspend fun provideYWrapped() = coroutineBinding {
provideY().bind()
}

suspend fun provideZ(): Result<Int, BindingError.BindingErrorB> {
delay(100)
zStateChange = true
return Ok(1)
}

suspend fun provideZWrapped() = coroutineBinding {
provideZ().bind()
}

val dispatcherA = StandardTestDispatcher(testScheduler)
val dispatcherB = StandardTestDispatcher(testScheduler)
val dispatcherC = StandardTestDispatcher(testScheduler)

val result: Result<Int, BindingError> = coroutineBinding {
val x = async(dispatcherA) { provideXWrapped().bind() }
val y = async(dispatcherB) { provideYWrapped().bind() }

testScheduler.advanceTimeBy(2)
testScheduler.runCurrent()

val z = async(dispatcherC) { provideZWrapped().bind() }

x.await() + y.await() + z.await()
}

assertEquals(
expected = Err(BindingError.BindingErrorA),
actual = result
)

assertTrue(xStateChange)
assertTrue(yStateChange)
assertFalse(zStateChange)
}
}
44 changes: 36 additions & 8 deletions ...es/src/commonTest/kotlin/com/github/michaelbull/result/coroutines/CoroutineBindingTest.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -12,7 +12,11 @@ import kotlin.test.assertTrue

class CoroutineBindingTest {

private object BindingError
private sealed interface BindingError {
data object BindingErrorA : BindingError
data object BindingErrorB : BindingError
data object BindingErrorC : BindingError
}

@Test
fun returnsOkIfAllBindsSuccessful() = runTest {
Expand Down Expand Up @@ -71,7 +75,7 @@ class CoroutineBindingTest {

suspend fun provideY(): Result<Int, BindingError> {
delay(1)
return Err(BindingError)
return Err(BindingError.BindingErrorA)
}

suspend fun provideZ(): Result<Int, BindingError> {
Expand All @@ -87,7 +91,7 @@ class CoroutineBindingTest {
}

assertEquals(
expected = Err(BindingError),
expected = Err(BindingError.BindingErrorA),
actual = result,
)
}
Expand All @@ -107,13 +111,13 @@ class CoroutineBindingTest {
suspend fun provideY(): Result<Int, BindingError> {
delay(10)
yStateChange = true
return Err(BindingError)
return Err(BindingError.BindingErrorA)
}

suspend fun provideZ(): Result<Int, BindingError> {
delay(1)
zStateChange = true
return Err(BindingError)
return Err(BindingError.BindingErrorA)
}

val result: Result<Int, BindingError> = coroutineBinding {
Expand All @@ -124,7 +128,7 @@ class CoroutineBindingTest {
}

assertEquals(
expected = Err(BindingError),
expected = Err(BindingError.BindingErrorA),
actual = result,
)

Expand All @@ -142,7 +146,7 @@ class CoroutineBindingTest {

suspend fun provideY(): Result<String, BindingError> {
delay(1)
return Err(BindingError)
return Err(BindingError.BindingErrorA)
}

suspend fun provideZ(): Result<Int, BindingError> {
Expand All @@ -158,8 +162,32 @@ class CoroutineBindingTest {
}

assertEquals(
expected = Err(BindingError),
expected = Err(BindingError.BindingErrorA),
actual = result,
)
}

@Test
fun shouldHandleExceptionsWithMultipleNestedBindings() = runTest {
val result: Result<Int, BindingError> = coroutineBinding {
val b: Result<Int, BindingError> = coroutineBinding {
val c: Result<Int, BindingError> = coroutineBinding {
Err(BindingError.BindingErrorC).bind()
}

assertEquals(Err(BindingError.BindingErrorC), c)

Ok(2).bind()
}

assertEquals(Ok(2), b)

Err(BindingError.BindingErrorB).bind()
}

assertEquals(
expected = Err(BindingError.BindingErrorB),
actual = result
)
}
}