# multiplatform

Jeff Lockhart

07/09/2022, 3:19 PM
How do you test async callbacks in commonTest (to run on Android and iOS)? Android tests run on TestRunner's pseudo main thread, allowing callbacks to call the real main thread in parallel. But iOS runs tests on the actual main thread, causing callbacks to deadlock while test code waits on the same thread. Is there a way to either change this behavior of which thread iOS tests are run on, or write tests in a way that works on both platforms?
I filed a YouTrack issue for this.