<https://kotlinlang.slack.com/archives/C1CFAFJSK/p1551199064120900>

# multiplatform

[pardom]

https://kotlinlang.slack.com/archives/C1CFAFJSK/p1551199064120900

[basher]

I think it is in common. I'm currently running tests using it

[basher]

I have fun into IDE issues before getting it to be recognized

[pardom]

It’s in JVM and Native, but not core. https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines/run-blocking.html

[basher]

Huh. I guess we only build for JVM and native, which explains why that works

[basher]

Sorry!

[pardom]

Using an instance of CoroutineDispatcher local to the test class did the trick: https://gist.github.com/pardom/74a9f1abc17688badf6b8dc06e13b1d2#file-runtimetest-kt-L13-L17

[nestserau]

You can reimplement runBlocking:

common

expect fun <T> runBlocking(block: suspend () -> T): T

ios

actual fun <T> runBlocking(block: suspend () -> T): T {
    val expectation = Expectation<T>()

    GlobalScope.launch(MainRunLoopDispatcher) {
        expectation.fulfill(block.invoke())
    }

    return expectation.wait() ?: throw RuntimeException("runBlocking failed")
}

private object MainRunLoopDispatcher : CoroutineDispatcher() {
    override fun dispatch(context: CoroutineContext, block: Runnable) {
        NSRunLoop.mainRunLoop().performBlock {
            block.run()
        }
    }
}

android

actual fun <T> runBlocking(block: suspend () -> T): T = kotlinx.coroutines.runBlocking { block.invoke() }

I’m not the original author, but I don’t remember the original author unfortunately. Hope that helps.

[jw]

the common pattern is to expect/actual it

[russhwolf]

If you don't need js, you can add your own expect/actual declarations to get runblocking in jvm/native.

[jw]

even in JS is still works because you can return a promise from the test APIs

[jw]

and the runner will wait

[jw]

this will all be obviated once @Test suspend fun lands though

[russhwolf]

Yeah the ticket for @Test suspend has more details on workarounds: https://youtrack.jetbrains.com/issue/KT-22228

[jw]

1.3.30 🤞