test: add withTimeoutSafe and delaySafe as a safe replacements fo…

…r `withTimeout`/`delay` when used inside `TestScope` More info: Kotlin/kotlinx.coroutines#3588 https://github.com/Kotlin/kotlinx.coroutines/blob/dea2ca5/kotlinx-coroutines-test/README.md#using-withtimeout-inside-runtest Signed-off-by: Artyom Shendrik <[email protected]>
fluxo-kt · Feb 27, 2023 · 8367b2f · 8367b2f
1 parent 5f389a1
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Showing 10 changed files with 269 additions and 33 deletions.
diff --git a/fluxo-core/src/commonTest/kotlin/kt/fluxo/test/DelaySafe.kt b/fluxo-core/src/commonTest/kotlin/kt/fluxo/test/DelaySafe.kt
@@ -0,0 +1,26 @@
+package kt.fluxo.test
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.test.TestScope
+import kotlinx.coroutines.test.runTest
+import kotlinx.coroutines.withContext
+
+/**
+ * Use as a safe replacement for [delay] when used inside a [runTest]/[TestScope].
+ *
+ * Delays coroutine for a given time without blocking a thread and resumes it after a specified time.
+ *
+ * [Documentation on delay-skipping in tests](https://github.com/Kotlin/kotlinx.coroutines/blob/81e17dd/kotlinx-coroutines-test/README.md#delay-skipping)
+ *
+ * @param timeMillis timeout time in milliseconds.
+ *
+ * @see delay
+ * @see withTimeoutSafe
+ */
+@Suppress("MaxLineLength")
+suspend fun delaySafe(timeMillis: Long) {
+    withContext(Dispatchers.Default) {
+        delay(timeMillis)
+    }
+}
diff --git a/fluxo-core/src/commonTest/kotlin/kt/fluxo/test/TestFlowObserver.kt b/fluxo-core/src/commonTest/kotlin/kt/fluxo/test/TestFlowObserver.kt
@@ -7,11 +7,8 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.TimeoutCancellationException
 import kotlinx.coroutines.cancel
-import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.launch
-import kotlinx.coroutines.withContext
-import kotlinx.coroutines.withTimeout
 
 
 /**
@@ -45,18 +42,15 @@ class TestFlowObserver<T>(flow: Flow<T>) {
      * @param throwTimeout Throw if timed out (by default)
      */
     suspend fun awaitFor(timeout: Long = 5000L, throwTimeout: Boolean = true, condition: TestFlowObserver<T>.() -> Boolean) {
-        // https://github.com/Kotlin/kotlinx.coroutines/blob/master/kotlinx-coroutines-test/README.md#using-withtimeout-inside-runtest
-        withContext(Dispatchers.Default) {
-            try {
-                withTimeout(timeout) {
-                    @Suppress("UNUSED_EXPRESSION")
-                    while (!condition()) {
-                        delay(AWAIT_TIMEOUT_MS)
-                    }
+        try {
+            withTimeoutSafe(timeout) {
+                @Suppress("UNUSED_EXPRESSION")
+                while (!condition()) {
+                    delaySafe(AWAIT_TIMEOUT_MS)
                 }
-            } catch (e: TimeoutCancellationException) {
-                if (throwTimeout) throw e
             }
+        } catch (e: TimeoutCancellationException) {
+            if (throwTimeout) throw e
         }
     }
 

diff --git a/fluxo-core/src/commonTest/kotlin/kt/fluxo/test/WithTimeoutSafe.kt b/fluxo-core/src/commonTest/kotlin/kt/fluxo/test/WithTimeoutSafe.kt
@@ -0,0 +1,42 @@
+package kt.fluxo.test
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.TimeoutCancellationException
+import kotlinx.coroutines.currentCoroutineContext
+import kotlinx.coroutines.test.TestScope
+import kotlinx.coroutines.test.runTest
+import kotlinx.coroutines.withContext
+import kotlinx.coroutines.withTimeout
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
+
+/**
+ * Use as a safe replacement for [withTimeout] when used inside a [runTest]/[TestScope].
+ *
+ * Runs a given suspending [block] of code inside a coroutine with a specified [timeout][timeMillis] and throws
+ * a [TimeoutCancellationException] if the timeout was exceeded.
+ *
+ * [Issue with the problem](https://github.com/Kotlin/kotlinx.coroutines/issues/3588)
+ *
+ * [Documented as intended behavior](https://github.com/Kotlin/kotlinx.coroutines/blob/master/kotlinx-coroutines-test/README.md#using-withtimeout-inside-runtest)
+ *
+ * @param timeMillis timeout time in milliseconds.
+ *
+ * @see withTimeout
+ * @see delaySafe
+ */
+@Suppress("MaxLineLength")
+suspend inline fun <T> withTimeoutSafe(timeMillis: Long, crossinline block: suspend CoroutineScope.() -> T): T {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    val context = currentCoroutineContext()
+    return withContext(Dispatchers.Default) {
+        withTimeout(timeMillis) {
+            withContext(context) {
+                block()
+            }
+        }
+    }
+}
diff --git a/fluxo-core/src/commonTest/kotlin/kt/fluxo/tests/ContainerExceptionHandlerTest.kt b/fluxo-core/src/commonTest/kotlin/kt/fluxo/tests/ContainerExceptionHandlerTest.kt
@@ -2,22 +2,20 @@ package kt.fluxo.tests
 
 import kotlinx.coroutines.CoroutineExceptionHandler
 import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
-import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.test.TestScope
-import kotlinx.coroutines.withContext
 import kotlinx.coroutines.yield
 import kt.fluxo.core.FluxoClosedException
 import kt.fluxo.core.closeAndWait
 import kt.fluxo.core.container
 import kt.fluxo.core.updateState
+import kt.fluxo.test.delaySafe
 import kt.fluxo.test.getValue
 import kt.fluxo.test.runUnitTest
 import kt.fluxo.test.setValue
@@ -116,9 +114,7 @@ class ContainerExceptionHandlerTest {
                 flow {
                     while (true) {
                         emit(Unit)
-                        withContext(Dispatchers.Default) {
-                            delay(1000)
-                        }
+                        delaySafe(1000)
                     }
                 }.collect()
             } catch (ce: CancellationException) {

diff --git a/fluxo-core/src/commonTest/kotlin/kt/fluxo/tests/ContainerThreadingTest.kt b/fluxo-core/src/commonTest/kotlin/kt/fluxo/tests/ContainerThreadingTest.kt
@@ -1,13 +1,13 @@
 package kt.fluxo.tests
 
 import kotlinx.coroutines.coroutineScope
-import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.test.runTest
 import kt.fluxo.core.Container
 import kt.fluxo.core.container
 import kt.fluxo.core.updateState
 import kt.fluxo.test.CoroutineScopeAwareTest
+import kt.fluxo.test.delaySafe
 import kt.fluxo.test.test
 import kotlin.random.Random
 import kotlin.test.Test
@@ -24,7 +24,7 @@ internal class ContainerThreadingTest : CoroutineScopeAwareTest() {
         val newState = Random.nextInt()
 
         container.send {
-            delay(Long.MAX_VALUE)
+            delaySafe(Long.MAX_VALUE)
         }
         container.send {
             updateState { newState }
@@ -104,7 +104,7 @@ internal class ContainerThreadingTest : CoroutineScopeAwareTest() {
 
     private fun Container<TestState, Nothing>.one(delay: Boolean = false) = send {
         if (delay) {
-            delay(Random.nextLong(20))
+            delaySafe(Random.nextLong(20))
         }
         updateState {
             it.copy(ids = value.ids + 1)
@@ -113,7 +113,7 @@ internal class ContainerThreadingTest : CoroutineScopeAwareTest() {
 
     private fun Container<TestState, Nothing>.two(delay: Boolean = false) = send {
         if (delay) {
-            delay(Random.nextLong(20))
+            delaySafe(Random.nextLong(20))
         }
         updateState {
             it.copy(ids = value.ids + 2)
@@ -122,7 +122,7 @@ internal class ContainerThreadingTest : CoroutineScopeAwareTest() {
 
     private fun Container<TestState, Nothing>.three(delay: Boolean = false) = send {
         if (delay) {
-            delay(Random.nextLong(20))
+            delaySafe(Random.nextLong(20))
         }
         updateState {
             it.copy(ids = value.ids + 3)

diff --git a/fluxo-core/src/commonTest/kotlin/kt/fluxo/tests/InputStrategyTest.kt b/fluxo-core/src/commonTest/kotlin/kt/fluxo/tests/InputStrategyTest.kt
@@ -5,7 +5,6 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers.Unconfined
 import kotlinx.coroutines.channels.BufferOverflow
 import kotlinx.coroutines.channels.Channel
-import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.flow.first
@@ -30,6 +29,7 @@ import kt.fluxo.test.IgnoreNativeAndJs
 import kt.fluxo.test.KMM_PLATFORM
 import kt.fluxo.test.Platform
 import kt.fluxo.test.TestLoggingStoreFactory
+import kt.fluxo.test.delaySafe
 import kt.fluxo.test.runUnitTest
 import kotlin.random.Random
 import kotlin.test.Ignore
@@ -80,7 +80,7 @@ internal class InputStrategyTest : CoroutineScopeAwareTest() {
                         finishLock.unlock()
                     }
                 } else if (intent == lastValue) {
-                    if (generic) delay(timeMillis = 25)
+                    if (generic) delaySafe(timeMillis = 25)
                     finishLock.unlock()
                 }
             },
@@ -95,7 +95,7 @@ internal class InputStrategyTest : CoroutineScopeAwareTest() {
         if ((generic || parallel) && (nonOrderedEqual || equal)) {
             // TODO: Store.awaitIdle()
             while (results.size < NUMBER_OF_ITEMS) {
-                delay(timeMillis = 10)
+                delaySafe(timeMillis = 10)
             }
         }
         store.closeAndWait()

diff --git a/fluxo-core/src/commonTest/kotlin/kt/fluxo/tests/SideJobTest.kt b/fluxo-core/src/commonTest/kotlin/kt/fluxo/tests/SideJobTest.kt
@@ -11,6 +11,7 @@ import kt.fluxo.core.dsl.accept
 import kt.fluxo.core.intent
 import kt.fluxo.core.store
 import kt.fluxo.core.updateState
+import kt.fluxo.test.delaySafe
 import kt.fluxo.test.runUnitTest
 import kotlin.test.Ignore
 import kotlin.test.Test
@@ -135,9 +136,7 @@ internal class SideJobTest {
         store.intent {
             sideJob { wasRestarted ->
                 assertFalse(wasRestarted)
-                withContext(Dispatchers.Default) {
-                    delay(timeMillis = 1_000)
-                }
+                delaySafe(timeMillis = 1_000)
                 updateState { "a" }
             }
             sideJob { wasRestarted ->