在单元测试中调用Dispatchers.setMain()时出错

Question

已开始尝试在JUnit单元测试中使用kotlinx-coroutines-test(https://github.com/Kotlin/kotlinx.coroutines/blob/master/core/kotlinx-coroutines-test/README.md)但在我调用时遇到以下错误Dispatchers.setMain()

java.lang.IllegalArgumentException: TestMainDispatcher is not set as main dispatcher, have Main[missing, cause=java.lang.AbstractMethodError: kotlinx.coroutines.test.internal.TestMainDispatcherFactory.createDispatcher()Lkotlinx/coroutines/MainCoroutineDispatcher;] instead.

    at kotlinx.coroutines.test.TestDispatchers.setMain(TestDispatchers.kt:22)

我试过打电话Dispatchers.setMain(Dispatchers.Unconfined)也传入了val mainThreadSurrogate = newSingleThreadContext("UI thread").看起来似乎问题不是传递价值,而是mainDispatcher在接下来的测试中绊倒

public fun Dispatchers.setMain(dispatcher: CoroutineDispatcher) {
    require(dispatcher !is TestMainDispatcher) { "Dispatchers.setMain(Dispatchers.Main) is prohibited, probably Dispatchers.resetMain() should be used instead" }
    val mainDispatcher = Dispatchers.Main
    require(mainDispatcher is TestMainDispatcher) { "TestMainDispatcher is not set as main dispatcher, have $mainDispatcher instead." }
    mainDispatcher.setDispatcher(dispatcher)
}

Answer 1

尝试添加核心作为测试的依赖项.它解决了我的问题.

testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.1.0")

Answer 2

结果问题是我使用的是旧版本的kotlinx-coroutines-core依赖项。当我更新到 v1.1.0 时，它起作用了（感谢 @vigit 帮助触发了这一实现！）