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)，但在调用 Dispatchers.setMain()

时出现以下错误

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)

我试过调用 Dispatchers.setMain(Dispatchers.Unconfined) 并传入 val mainThreadSurrogate = newSingleThreadContext("UI thread")。看起来问题不在于传入的值，而是在接下来的 mainDispatcher 测试中被绊倒了

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

尝试将核心添加为测试的依赖项。它解决了我的问题。

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

Answer 2

原来的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 帮助触发了这个实现！）

在单元测试中调用 Dispatchers.setMain() 时出错

Error calling Dispatchers.setMain() in unit test

android

coroutine

kotlin

kotlinx.coroutines