| commit | 1245d7edb0ec61848b620691406b79c370d706d5 | [log] [tgz] |
|---|---|---|
| author | Dmitry Khalanskiy <[email protected]> | Fri Feb 24 20:45:49 2023 +0300 |
| committer | GitHub <[email protected]> | Fri Feb 24 20:45:49 2023 +0300 |
| tree | 2ce59da800296b92a93dc6daa82c52668c8a9b32 | |
| parent | 747db9e47c44eeb2de4830cde34e0fde6f40b44a [diff] |
Attempt to report uncaught exceptions in the test module (#3449) When when a `Job` doesn't have a parent, failures in it can not be reported via structured concurrency. Instead, the mechanism of unhandled exceptions is used. If there is a `CoroutineExceptionHandler` in the coroutine context or registered as a `ServiceLoader` service, this gets notified, and otherwise, something platform-specific happens: on Native, the program crashes, and on the JVM, by default, the exception is just logged, though this is configurable via `Thread.setUncaughtExceptionHandler`. With tests on the JVM, this is an issue: we want exceptions not simply *logged*, we want them to fail the test, and this extends beyond just coroutines. However, JUnit does not override the uncaught exception handler, and uncaught exceptions do just get logged: <https://stackoverflow.com/questions/36648317/how-to-capture-all-uncaucht-exceptions-on-junit-tests> This is a problem with a widely-used `viewModelScope` on Android. This is a scope without a parent, and so the exceptions in it are uncaught. On Android, such uncaught exceptions crash the app by default, but in tests, they just get logged. Clearly, without overriding the behavior of uncaught exceptions, the tests are lacking. This can be solved on the test writers' side via `setUncaughtExceptionHandler`, but one has to remember to do that. In this commit, we attempt to solve this issue for the overwhelming majority of users. To that end, when the test framework is used, we collect the uncaught exceptions and report them at the end of a test. This approach is marginally less robust than `setUncaughtExceptionHandler`: if an exception happened after the last test using `kotlinx-coroutines-test`, it won't get reported, for example. `CoroutineExceptionHandler` is designed in such a way that, when it is used in a coroutine context, its presence means that the exceptions are safe in its care and will not be propagated further, but when used as a service, it has no such property. We, however, know that our `CoroutineExceptionHandler` reports the exceptions properly and they don't need to be further logged, and so we had to extend the behavior of mechanism for uncaught exception handling so that the handler throws a new kind of exception if the exception was processed successfully. Also, because there's no `ServiceLoader` mechanism on JS or Native, we had to refactor the whole uncaught exception handling mechanism a bit in the same vein as we had to adapt the `Main` dispatcher to `Dispatchers.setMain`: by introducing internal setter APIs that services have to call manually to register in. Fixes #1205 as thoroughly as we can, given the circumstances.
Library support for Kotlin coroutines with multiplatform support. This is a companion version for the Kotlin 1.8.10 release.
suspend fun main() = coroutineScope { launch { delay(1000) println("Kotlin Coroutines World!") } println("Hello") }
Play with coroutines online here
CompletableFuture and JVM-specific extensions.Promise via Promise.await and promise builder;Window via Window.asCoroutineDispatcher, etc.Add dependencies (you can also add other modules that you need):
<dependency> <groupId>org.jetbrains.kotlinx</groupId> <artifactId>kotlinx-coroutines-core</artifactId> <version>1.6.4</version> </dependency>
And make sure that you use the latest Kotlin version:
<properties> <kotlin.version>1.8.10</kotlin.version> </properties>
Add dependencies (you can also add other modules that you need):
dependencies { implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4") }
And make sure that you use the latest Kotlin version:
plugins { // For build.gradle.kts (Kotlin DSL) kotlin("jvm") version "1.8.10" // For build.gradle (Groovy DSL) id "org.jetbrains.kotlin.jvm" version "1.8.10" }
Make sure that you have mavenCentral() in the list of repositories:
repositories { mavenCentral() }
Add kotlinx-coroutines-android module as a dependency when using kotlinx.coroutines on Android:
implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.4")
This gives you access to the Android Dispatchers.Main coroutine dispatcher and also makes sure that in case of a crashed coroutine with an unhandled exception that this exception is logged before crashing the Android application, similarly to the way uncaught exceptions in threads are handled by the Android runtime.
R8 and ProGuard rules are bundled into the kotlinx-coroutines-android module. For more details see “Optimization” section for Android.
The kotlinx-coroutines-core artifact contains a resource file that is not required for the coroutines to operate normally and is only used by the debugger. To exclude it at no loss of functionality, add the following snippet to the android block in your Gradle file for the application subproject:
packagingOptions { resources.excludes += "DebugProbesKt.bin" }
Core modules of kotlinx.coroutines are also available for Kotlin/JS and Kotlin/Native.
In common code that should get compiled for different platforms, you can add a dependency to kotlinx-coroutines-core right to the commonMain source set:
commonMain { dependencies { implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4") } }
No more additional dependencies are needed, platform-specific artifacts will be resolved automatically via Gradle metadata available since Gradle 5.3.
Platform-specific dependencies are recommended to be used only for non-multiplatform projects that are compiled only for target platform.
Kotlin/JS version of kotlinx.coroutines is published as kotlinx-coroutines-core-js (follow the link to get the dependency declaration snippet) and as kotlinx-coroutines-core NPM package.
Kotlin/Native version of kotlinx.coroutines is published as kotlinx-coroutines-core-$platform where $platform is the target Kotlin/Native platform. List of currently supported targets.