Test Robot with Execute around example

ArticleListViewModelRobot.kt

class ArticleListViewModelRobot private constructor() {

    private lateinit var viewModel: ArticleListViewModel
    private val fakeRepository = FakeArticleRepository()
    
    private fun setup() {
        buildViewModel()
    }

    fun buildViewModel() = apply {
        viewModel = ArticleListViewModel(
            articleRepository = fakeRepository
        )
    }

    // actions
    suspend fun emitArticles(articles: List<Article>) = apply {
        fakeRepository.emitArticles(articles)
    }
    
    // all assert functions

    fun assertArticleWasPersisted(article: Article) = apply {
        // assert
    }

    private fun cleanUp() = apply {
        fakeRepository.closeChannel()
    }

    companion object {
        fun test(action: suspend (ArticleListViewModelRobot) -> Unit) {

            val testRobot = ArticleListViewModelRobot()
			testRobot.setup()
            runBlockingTest {
                action(testRobot)
            }
            testRobot.cleanUp()
        }
    }
}

ArticleListViewModelTest.kt

@ExperimentalCoroutinesApi
class ArticleListViewModelTest {
		@Test
    fun successfulRequest() = runBlockingTest {
        val testArticles = listOf(
            Article(
                htmlTitle = HtmlString("Test String"),
                author = "",
                url = ""
            )
        )

	// notice the user of TestRobot doesn't have to worry about setups and cleanups/teardowns
        ArticleListViewModelRobot.test {
            it.assertViewState(
                    expectedViewState = ArticleListViewState.Loading
                )
                .emitArticles(testArticles)
                .assertViewState(
                    expectedViewState = ArticleListViewState.Success(testArticles)
                )
                .assertNumberOfCallsToFetchArticles(1)
        }
    }
}