This Day In History Jetpack Compose App - Welcome Screen UI Tests

Objective:

Add android UI tests for the Welcome Screen. At the end of this exercise, all individual tests within the Welcome Screen scenario should succeed.

Components built

We will add or modify the following components:

• testExtensions.kt: Helper methods for asserting navigation test scenarios
• introNavGraphTest.kt: test graph for testing navigation
• WelcomeScreenScenarioTest.kt: Class for testing Welcome Screen

Code

testExtensions.kt

Modify testExtensions.kt in the com.coroutines.thisdayinhistory.helpers package in the androidTest source set:

// add:
fun NavController.assertCurrentRouteName(expectedRouteName: String) {
    Assert.assertEquals(expectedRouteName, currentBackStackEntry?.destination?.route)
}

introGraphTest.kt

Add introGraphTest.kt to the com.coroutines.thisdayinhistory.graph package in the androidTest source set:

package com.coroutines.thisdayinhistory.graph


import androidx.compose.runtime.collectAsState
import androidx.navigation.NavController
import androidx.navigation.NavGraphBuilder
import androidx.navigation.compose.composable
import androidx.navigation.navigation
import com.coroutines.thisdayinhistory.ui.screens.language.LanguageScreen
import com.coroutines.thisdayinhistory.ui.screens.welcome.WelcomeScreen
import com.coroutines.thisdayinhistory.ui.viewmodels.ISettingsViewModel
import com.coroutines.thisdayinhistory.ui.viewmodels.IWelcomeViewModel


fun NavGraphBuilder.introGraphTest(navController: NavController, viewModel: ISettingsViewModel, welcomeViewModel: IWelcomeViewModel) {
    navigation(startDestination = IntroNavOption.WelcomeScreen.name, route = NavRoutes.IntroRoute.name) {
        composable(IntroNavOption.WelcomeScreen.name){
            val appConfState = viewModel.appConfigurationState.collectAsState().value
            WelcomeScreen(navController, appConfState, welcomeViewModel)
        }
        composable(IntroNavOption.LanguagesScreen.name + "/{prompt}"){ backStackEntry ->
            val prompt = backStackEntry.arguments?.getString("prompt") ?: "Please choose your language"
            LanguageScreen(navController= navController,
                viewModel = viewModel,
                languagePrompt =  prompt)
        }
    }
}

Welcome Screen Test Scenario

Add WelcomeScreenScenarioTest.kt to the com.coroutines.thisdayinhistory.screens.about package in the androidTest sourceset:

package com.coroutines.thisdayinhistory.screens.welcome


import androidx.compose.ui.test.assertIsDisplayed
import androidx.compose.ui.test.assertTextContains
import androidx.compose.ui.test.junit4.createComposeRule
import androidx.compose.ui.test.onAllNodesWithTag
import androidx.compose.ui.test.onAllNodesWithText
import androidx.compose.ui.test.onNodeWithTag
import androidx.navigation.NavHostController
import androidx.navigation.compose.NavHost
import androidx.navigation.compose.rememberNavController
import assertCurrentRouteName
import com.coroutines.thisdayinhistory.graph.IntroNavOption
import com.coroutines.thisdayinhistory.graph.MainNavOption
import com.coroutines.thisdayinhistory.graph.NavRoutes
import com.coroutines.thisdayinhistory.graph.introGraphTest
import com.coroutines.thisdayinhistory.ui.constants.LANGUAGE_SELECTION_TEXT_TAG
import com.coroutines.thisdayinhistory.ui.constants.WELCOME_MESSAGE_TEXT_TAG
import com.coroutines.thisdayinhistory.ui.screens.welcome.WelcomeScreen
import com.coroutines.thisdayinhistory.ui.state.WelcomeScreenUiState
import com.coroutines.thisdayinhistory.ui.theme.ThisDayInHistoryTheme
import com.coroutines.thisdayinhistory.ui.viewmodels.SettingsViewModelMock
import com.coroutines.thisdayinhistory.ui.viewmodels.WelcomeViewModelMock
import org.junit.Rule
import org.junit.Test

class WelcomeScreenScenarioTest {

    @get:Rule
    val composeTestRule = createComposeRule()
    private lateinit var navController: NavHostController// TestNavHostController
    private val welcomeScreenTag = WELCOME_MESSAGE_TEXT_TAG
    private val expectedDefaultText = "Welcome to our app!"
    private val settingsViewModel = SettingsViewModelMock()


    @Test
    fun screenInitialStateTest() {
        composeTestRule.setContent {
            val navController = rememberNavController()
            val appSettingsState = settingsViewModel.appConfigurationState.value
            val viewModel = WelcomeViewModelMock(WelcomeScreenUiState.Initial(expectedDefaultText))
            ThisDayInHistoryTheme(viewModel = settingsViewModel) {
                WelcomeScreen(navController, appSettingsState, viewModel)
            }
        }

        composeTestRule.onNodeWithTag(welcomeScreenTag)
            .assertIsDisplayed()
            .assertTextContains(expectedDefaultText, true)
    }


    @Test
    fun welcomeTransitionsToLanguagesOnErrorTest() {
        composeTestRule.setContent {
            navController = rememberNavController()
            val welcomeViewModel = WelcomeViewModelMock(WelcomeScreenUiState.Error("error"))
            ThisDayInHistoryTheme(viewModel = settingsViewModel) {
                NavHost(
                    navController = navController,
                    startDestination = NavRoutes.IntroRoute.name
                ) {
                    introGraphTest(navController, settingsViewModel, welcomeViewModel)
                }
            }
        }


        composeTestRule.mainClock.advanceTimeBy(3999)

        composeTestRule.waitUntil(timeoutMillis = 5900) {
            composeTestRule
                .onAllNodesWithTag(LANGUAGE_SELECTION_TEXT_TAG)
                .fetchSemanticsNodes().size == 9
        }
        navController.assertCurrentRouteName(IntroNavOption.LanguagesScreen.name + "/{prompt}")


    }


    @Test
    fun welcomeTransitionsToLanguagesOnSuccessTest() {
        composeTestRule.setContent {
            navController = rememberNavController()
            val welcomeViewModel = WelcomeViewModelMock(WelcomeScreenUiState.Success("translated"))
            ThisDayInHistoryTheme(viewModel = settingsViewModel) {
                NavHost(
                    navController = navController,
                    startDestination = NavRoutes.IntroRoute.name
                ) {
                    introGraphTest(navController, settingsViewModel, welcomeViewModel)
                }
            }
        }

        composeTestRule.mainClock.advanceTimeBy(3999)

        composeTestRule.waitUntil(timeoutMillis = 5900) {
            composeTestRule
                .onAllNodesWithTag(LANGUAGE_SELECTION_TEXT_TAG)
                .fetchSemanticsNodes().size == 9

        }
        navController.assertCurrentRouteName(IntroNavOption.LanguagesScreen.name + "/{prompt}")
    }


    @Test
    fun welcomeOnInitialStateTest() {
        composeTestRule.setContent {
            navController = rememberNavController()
            val welcomeViewModel = WelcomeViewModelMock(WelcomeScreenUiState.Initial("welcome"))
            ThisDayInHistoryTheme(viewModel = settingsViewModel) {
                NavHost(
                    navController = navController,
                    startDestination = NavRoutes.IntroRoute.name
                ) {
                    introGraphTest(navController, settingsViewModel, welcomeViewModel)
                }
            }
        }

        composeTestRule.mainClock.advanceTimeByFrame()

        navController.assertCurrentRouteName(IntroNavOption.WelcomeScreen.name)
    }

    @Test
     fun welcomeOnSuccessStateStaysOnWelcomeForAtLeast2SecondsTest() {
        composeTestRule.setContent {
            navController = rememberNavController()
            val welcomeViewModel = WelcomeViewModelMock(WelcomeScreenUiState.Success("translated"))
            ThisDayInHistoryTheme(viewModel = settingsViewModel) {
                NavHost(
                    navController = navController,
                    startDestination = NavRoutes.IntroRoute.name
                ) {
                    introGraphTest(navController, settingsViewModel, welcomeViewModel)
                }
            }
        }

        composeTestRule.mainClock.advanceTimeBy(1800)
        composeTestRule.runOnIdle {
            navController.assertCurrentRouteName(IntroNavOption.WelcomeScreen.name)
        }
    }

    @Test
    fun welcomeOnSuccessStateTransitions2LanguagesAfter3SecondsTest() {


        composeTestRule.setContent {
            navController = rememberNavController()
            val welcomeViewModel = WelcomeViewModelMock(WelcomeScreenUiState.Success("translated"))
            ThisDayInHistoryTheme(viewModel = settingsViewModel) {
                NavHost(
                    navController = navController,
                    startDestination = NavRoutes.IntroRoute.name
                ) {
                    introGraphTest(navController, settingsViewModel, welcomeViewModel)
                }
            }
        }

        composeTestRule.waitUntil(timeoutMillis = 5100) {
            composeTestRule
                .onAllNodesWithTag(LANGUAGE_SELECTION_TEXT_TAG)
                .fetchSemanticsNodes().size == 9

        }

        navController.assertCurrentRouteName(IntroNavOption.LanguagesScreen.name + "/{prompt}")
    }
}