在单元测试中调用Dispatchers.setMain()时出错

已经开始尝试使用 kotlinx-coroutines-test ( https://github.com/Kotlin/kotlinx.coroutines/blob/master/core/kotlinx-coroutines-test/README.md 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) 而且还经过 val mainThreadSurrogate = newSingleThreadContext("UI thread") . 看起来问题并不是因为传递了值,而是因为它被绊倒了 mainDispatcher 测试如下

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)
}