Testing with corroutines

Let's say I have Worker class and I want to do long running tasks in the background until user stops it or it is cancelled. It changes state of the class while doing the work and I want to write tests how work progresses with each loop. For this example I want to check loopCounter value after first yield(). How can I achieve that? Or maybe I should use coroutines differently here?

class Worker(
    private val coroutineContext: CoroutineContext = Dispatchers.Default,
) {
    var loopCounter: Long = 0
        private set

    private var job: Job? = null

    fun start() {
        if (job?.isActive == true) return

        job = CoroutineScope(coroutineContext).launch {
            while (isActive && loopCounter < 100) {
                loopCounter++
                doWork()
                yield()
            }
        }
    }

    fun stop() {
        job?.cancel()
    }

    private suspend fun doWork() {
        // Your long-running task logic
        println("Loop $loopCounter running on thread: ${Thread.currentThread().name}")
    }
}

Example test:

    @Test
    fun `loopCounter increments with yield`() = runTest {
        val dispatcher = StandardTestDispatcher(testScheduler)
        val worker = Worker(dispatcher)
        worker.start()

        testScheduler.runCurrent()

        assertTrue(worker.loopCounter == 1L)
    }