The thread running

foo()

returns right away (

launch

starts the coroutine but then returns immediately). Once it's done, process ends.

If you want the process to live on, then you need to force a non-daemon thread to wait:

@Test 
fun foo() {
	runBlocking { //This blocks test thread
		intervalFlow(10)
	        .collect {
	            log("---- INTERVAL=$it")
	        }
    }
}

I haven't come across a unit testing framework that creates a process for each test execution. This means that any threads or coroutines you create in one test could still be running when other tests run if you don't clean up and wait for them.