ExposingEffectsTest.kt

    @Test
    fun channelShareInTest() {

        val scope = TestCoroutineScope()
        val _channel = Channel<Int>(capacity = 2, onBufferOverflow = BufferOverflow.DROP_OLDEST)
        val exposedFlow: SharedFlow<Int> = _channel
            .consumeAsFlow().shareIn(scope, SharingStarted.WhileSubscribed())

        val testResults = mutableListOf<Int>()
        val testResults2 = mutableListOf<Int>()

        runBlockingTest {
            _channel.send(0)
            _channel.send(1)
            _channel.send(2)
            val observer1 = exposedFlow

            val job1 = launch {
                observer1.toList(testResults)
            }

            val observer2 = exposedFlow

            val job2 = launch {
                observer2.toList(testResults2)
            }

            _channel.send(3)

            job1.cancel()
            job2.cancel()

            // The first observer gets buffer + new updates
            assertEquals(listOf(1, 2, 3), testResults)
            // Second observer only gets new updates
            assertEquals(listOf(3), testResults2)
        }
    }