ActivityScenario is null when executing the test

[dawidhyzy]

I get a null pointer exception when executing the tests. If I write the same test without Cucumber and use plain AndroidJUnitRunner the test as supposed to

👓 What did you see?

java.lang.NullPointerException
at androidx.test.internal.util.Checks.checkNotNull(Checks.java:38)
at androidx.test.ext.junit.rules.ActivityScenarioRule.getScenario(ActivityScenarioRule.java:125)
at androidx.compose.ui.test.junit4.AndroidComposeTestRule_androidKt.getActivityFromTestRule(AndroidComposeTestRule.android.kt:345)
at androidx.compose.ui.test.junit4.AndroidComposeTestRule_androidKt.access$getActivityFromTestRule(AndroidComposeTestRule.android.kt:1)
at androidx.compose.ui.test.junit4.AndroidComposeTestRule_androidKt$createAndroidComposeRule$1.invoke(AndroidComposeTestRule.android.kt:116)
at androidx.compose.ui.test.junit4.AndroidComposeTestRule_androidKt$createAndroidComposeRule$1.invoke(AndroidComposeTestRule.android.kt:116)
at androidx.compose.ui.test.junit4.AndroidComposeTestRule$special$$inlined$AndroidComposeUiTestEnvironment$1.getActivity(ComposeUiTest.android.kt:559)
at androidx.compose.ui.test.AndroidComposeUiTestEnvironment$AndroidComposeUiTestImpl.getActivity(ComposeUiTest.android.kt:389)
at androidx.compose.ui.test.AndroidComposeUiTestEnvironment$AndroidComposeUiTestImpl.setContent(ComposeUiTest.android.kt:466)
at androidx.compose.ui.test.junit4.AndroidComposeTestRule.setContent(AndroidComposeTestRule.android.kt:340)
at my.test.steps.Steps.I_open_the_App(Steps.kt:41)
at ✽.I open the App(file:/features/app-startup.feature:4)

✅ What did you expect to see?

Test runs

📦 Which tool/library version are you using?

io.cucumber:cucumber-android io.cucumber:cucumber-android-hilt

🔬 How could we reproduce it?

//Steps.kt
@HiltAndroidTest
class Steps : SemanticsNodeInteractionsProvider {
    @get:Rule(order = 0)
    val hiltRule = HiltAndroidRule(this)
    @get:Rule(order = 1)
    val composeTestRule = createAndroidComposeRule<HiltAppCompatActivity>()

    @Before
    fun setup() {
        hiltRule.inject()
    }

    @Given("I open the App")
    fun I_open_the_App() {
        composeTestRule.setContent {
            Box(Modifier.testTag("Tv").fillMaxSize()) {
                Box(
                    modifier = Modifier
                        .size(100.dp)
                        .align(Alignment.Center)
                        .background(Color.Blue)
                )
            }
        }
    }

    @Then("The TV tab is displayed")
    fun Then_the_TV_tab_is_displayed() {
        onNodeWithTag("Tv").assertIsDisplayed()
    }

    override fun onAllNodes(
        matcher: SemanticsMatcher,
        useUnmergedTree: Boolean
    ): SemanticsNodeInteractionCollection = composeTestRule.onAllNodes(matcher, useUnmergedTree)

    override fun onNode(
        matcher: SemanticsMatcher,
        useUnmergedTree: Boolean
    ): SemanticsNodeInteraction = composeTestRule.onNode(matcher, useUnmergedTree)
}

// HiltAppCompatActivity.kt
@AndroidEntryPoint
class HiltAppCompatActivity : AppCompatActivity()

// TestRunner.kt
@CucumberOptions(glue = ["my.test.steps"], features = ["features"])
class TestRunner : CucumberAndroidJUnitRunner() {
    override fun newApplication(cl: ClassLoader, className: String, context: Context): Application =
        super.newApplication(cl, HiltTestApplication::class.java.name, context)
}

Feature file

Feature: App startup

  Scenario: User opens the App
    Given I open the App
    Then The TV tab is displayed

Steps to reproduce the behavior:

1. Run test
2. See NullPointerException

📚 Any additional context?

Plain Compose test to compare.

@HiltAndroidTest
class ComposeTest {
    @get:Rule(order = 0)
    val hiltRule = HiltAndroidRule(this)
    @get:Rule(order = 1)
    val composeTestRule = createAndroidComposeRule<HiltAppCompatActivity>()

    @Test
    fun I_open_the_App() {
        composeTestRule.setContent {
            Box(Modifier.testTag("Tv").fillMaxSize()) {
                Box(
                    modifier = Modifier
                        .size(100.dp)
                        .align(Alignment.Center)
                        .background(Color.Blue)
                )
            }
        }
        composeTestRule.onNodeWithTag("Tv").assertIsDisplayed()
    }
}

[lsuski]

You are missing @WithJunitRule annotation. Also better place rules in separate file. Check readme and cuculator sample

[dawidhyzy]

I checked cukeulator before but it's hard to understand which steps are needed and which are showcase of different approach. I moved the Compose rule to a separate class:

// ComposeRuleHolder.kt
@WithJunitRule
@Singleton
class ComposeRuleHolder @Inject constructor() {
    @get:Rule(order = 1)
    val composeTestRule = createAndroidComposeRule<HiltAppCompatActivity>()
}

And updated the steps accordingly:

@HiltAndroidTest
class Steps(
    val composeRuleHolder: ComposeRuleHolder
) : SemanticsNodeInteractionsProvider by composeRuleHolder.composeTestRule {

    private val composeTestRule
        get() = composeRuleHolder.composeTestRule

    @Given("I open the App")
    fun I_open_the_App() {
        composeTestRule.setContent {
            Box(Modifier.testTag("Tv").fillMaxSize()) {
                Box(
                    modifier = Modifier
                        .size(100.dp)
                        .align(Alignment.Center)
                        .background(Color.Blue)
                )
            }
        }
    }

    @Then("The TV tab is displayed")
    fun Then_the_TV_tab_is_displayed() {
        onNodeWithTag("Tv").assertIsDisplayed()
    }
}

I keep getting the same exception. I tried adding @WithJunitRule to both rule holder and steps class but id didn't help.

[lsuski]

I need to check if createAndroidComposeRule could be somehow incompatible. Can you check with createComposeRule. I'm not sure why you need specific activity while you're setting custom composable in test

[dawidhyzy]

I tried createAndroidComposeRule and got the same result.

There are two reasons for using a specific activity

1. It's a workaround for this issue: https://github.com/google/dagger/issues/3394
2. I will have in-app language change test cases and for that, I need the host Activity to extend AppCompatActivity https://developer.android.com/guide/topics/resources/app-languages

For backward compatibility with previous Android versions, equivalent APIs are also available in AndroidX. However, the backward compatible APIs work with the AppCompatActivity context

I was checking the pull request and it looks like the cukeulator uses the latest changes that I think are not part of version 7.14.0 could that be a problem?

[lsuski]

Could be, I've tested locally with latest version and createAndroidComposeRule works fine

[lsuski]

But imho the only difference is that @Singleton and @Inject annotation in ComposeRuleHolder is actually ignored in version 7.14.0

[dawidhyzy]

@lsuski I found the problem. I had my steps in my.test.steps and test rules holder in my.test.rule packages. This was causing the NullPointerException despite options pointing to the right package @CucumberOptions(glue = ["my.test.steps"], features = ["features"]). After moving everything to the same package as the test runner and removing glue from the options everything works as expected. Is that a bug or my mistake? If it is a bug I can create a branch which reproduces this behaviour or provide more info.

[lsuski]

it is a mistake, glue points to package where cucumber can find steps, hooks, rules etc.. You can specify more than one package if you want